:root {
    /* Colors */
    --primary: #4F46E5;
    --primary-light: #818CF8;
    --primary-dark: #3730A3;
    --secondary: #06B6D4;
    --accent: #F59E0B;
    --success: #10B981;
    --danger: #EF4444;
    --warning: #F59E0B;
    --dark: #1F2937;
    --gray: #6B7280;
    --light: #F3F4F6;
    --white: #FFFFFF;
    
    /* Shadows */
    --shadow-sm: 0 1px 2px 0 rgba(0, 0, 0, 0.05);
    --shadow: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -1px rgba(0, 0, 0, 0.06);
    --shadow-md: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -2px rgba(0, 0, 0, 0.05);
    --shadow-lg: 0 15px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    --shadow-xl: 0 20px 25px -5px rgba(0, 0, 0, 0.1), 0 10px 10px -5px rgba(0, 0, 0, 0.04);
    
    /* Border radius */
    --radius-sm: 6px;
    --radius: 8px;
    --radius-md: 12px;
    --radius-lg: 16px;
    --radius-xl: 24px;
    
    /* Transitions */
    --transition-fast: 150ms ease;
    --transition: 200ms ease;
    --transition-slow: 300ms ease;
    
    /* Typography */
    --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans SC', sans-serif;
    --font-mono: 'SF Mono', 'Fira Code', monospace;
}
* { margin: 0; padding: 0; box-sizing: border-box; }
body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Noto Sans SC', sans-serif;
    background: linear-gradient(135deg, #f5f7fa 0%, #e4e8ec 100%);
    color: var(--dark);
    line-height: 1.6;
    min-height: 100vh;
}
a { color: var(--primary); text-decoration: none; transition: var(--transition); }
a:hover { color: var(--primary-dark); }
.header {
    background: var(--white);
    padding: 12px 0;
    box-shadow: var(--shadow);
    position: sticky;
    top: 0;
    z-index: 1000;
}

/* Button System */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius);
    border: none;
    cursor: pointer;
    transition: all var(--transition);
    text-decoration: none;
}

.btn:hover {
    transform: translateY(-2px);
    box-shadow: var(--shadow-md);
}

.btn:active {
    transform: translateY(0);
}

.btn-primary {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white);
}

.btn-secondary {
    background: linear-gradient(135deg, var(--secondary) 0%, #0891B2 100%);
    color: var(--white);
}

.btn-success {
    background: linear-gradient(135deg, var(--success) 0%, #059669 100%);
    color: var(--white);
}

.btn-danger {
    background: linear-gradient(135deg, var(--danger) 0%, #DC2626 100%);
    color: var(--white);
}

.btn-warning {
    background: linear-gradient(135deg, var(--warning) 0%, #D97706 100%);
    color: var(--white);
}

.btn-outline {
    background: transparent;
    border: 2px solid var(--primary);
    color: var(--primary);
}

.btn-outline:hover {
    background: var(--primary);
    color: var(--white);
}

.btn-sm {
    padding: 6px 12px;
    font-size: 12px;
}

.btn-lg {
    padding: 14px 28px;
    font-size: 16px;
}

.btn i {
    font-size: 1.1em;
}

/* Card System */
.card {
    background: var(--white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow);
    overflow: hidden;
    transition: all var(--transition);
}

.card:hover {
    box-shadow: var(--shadow-lg);
    transform: translateY(-4px);
}

.card-flat {
    box-shadow: none;
    border: 1px solid #E5E7EB;
}

.card-flat:hover {
    box-shadow: var(--shadow);
}

.card-header {
    padding: 16px 20px;
    border-bottom: 1px solid #E5E7EB;
    background: var(--light);
}

.card-body {
    padding: 20px;
}

.card-footer {
    padding: 16px 20px;
    border-top: 1px solid #E5E7EB;
    background: var(--light);
}

/* Stat Card */
.stat-card {
    background: var(--white);
    border-radius: var(--radius-md);
    padding: 24px;
    text-align: center;
    box-shadow: var(--shadow);
    transition: all var(--transition);
    border: 1px solid rgba(0,0,0,0.05);
}

.stat-card:hover {
    transform: translateY(-6px);
    box-shadow: var(--shadow-lg);
}

.stat-card .stat-icon {
    font-size: 48px;
    margin-bottom: 16px;
}

.stat-card .stat-value {
    font-size: 36px;
    font-weight: 800;
    color: var(--primary);
}

.stat-card .stat-title {
    color: var(--gray);
    margin-top: 8px;
    font-weight: 500;
    font-size: 14px;
}

/* Course Card */
.course-card {
    background: var(--white);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all var(--transition);
    border: 1px solid rgba(0,0,0,0.05);
}

.course-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.course-card .course-cover {
    position: relative;
    height: 180px;
    overflow: hidden;
}

.course-card .course-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.course-card:hover .course-cover img {
    transform: scale(1.05);
}

.course-card .course-cover-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 48px;
}

.course-card .course-type {
    position: absolute;
    top: 12px;
    right: 12px;
    background: rgba(0,0,0,0.7);
    color: var(--white);
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}

.course-card .course-info {
    padding: 16px;
}

.course-card .course-title {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--dark);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.course-card .course-meta {
    font-size: 12px;
    color: var(--gray);
    display: flex;
    justify-content: space-between;
}

/* School Card */
.school-card {
    background: var(--white);
    border-radius: var(--radius-md);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: all var(--transition);
    border: 1px solid rgba(0,0,0,0.05);
}

.school-card:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-lg);
}

.school-card .school-cover {
    height: 150px;
    overflow: hidden;
}

.school-card .school-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform var(--transition-slow);
}

.school-card:hover .school-cover img {
    transform: scale(1.05);
}

.school-card .school-cover-placeholder {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--accent) 0%, #D97706 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--white);
    font-size: 48px;
}

.school-card .school-info {
    padding: 16px;
}

.school-card .school-name {
    font-size: 15px;
    font-weight: 600;
    margin-bottom: 8px;
    color: var(--dark);
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}

.school-card .school-meta {
    font-size: 12px;
    color: var(--gray);
    display: flex;
    justify-content: space-between;
}

/* Form System */
.form-control {
    display: block;
    width: 100%;
    padding: 12px 16px;
    font-size: 14px;
    font-weight: 500;
    line-height: 1.5;
    color: var(--dark);
    background-color: var(--white);
    border: 2px solid #E5E7EB;
    border-radius: var(--radius);
    transition: all var(--transition);
}

.form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
    outline: none;
}

.form-control::placeholder {
    color: #9CA3AF;
}

.form-label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 600;
    color: var(--dark);
}

.form-group {
    margin-bottom: 20px;
}

.form-control.is-valid {
    border-color: var(--success);
}

.form-control.is-invalid {
    border-color: var(--danger);
}

select.form-control {
    appearance: none;
    background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 16 16'%3e%3cpath fill='none' stroke='%23343a40' stroke-linecap='round' stroke-linejoin='round' stroke-width='2' d='M2 5l6 6 6-6'/%3e%3c/svg%3e");
    background-repeat: no-repeat;
    background-position: right 12px center;
    background-size: 16px 12px;
    padding-right: 36px;
}

.input-icon {
    position: relative;
}

.input-icon .form-control {
    padding-left: 44px;
}

.input-icon i {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #9CA3AF;
    font-size: 16px;
}

.form-check {
    display: flex;
    align-items: center;
    gap: 8px;
}

.form-check input {
    width: 18px;
    height: 18px;
    cursor: pointer;
}

textarea.form-control {
    min-height: 100px;
    resize: vertical;
}

/* Table System */
.table {
    width: 100%;
    border-collapse: collapse;
}

.table th {
    padding: 12px 16px;
    font-size: 12px;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--gray);
    background: var(--light);
    border-bottom: 2px solid #E5E7EB;
    text-align: left;
}

.table td {
    padding: 14px 16px;
    font-size: 14px;
    color: var(--dark);
    border-bottom: 1px solid #F3F4F6;
    vertical-align: middle;
}

.table tbody tr {
    transition: background-color var(--transition-fast);
}

.table tbody tr:hover {
    background-color: #F9FAFB;
}

.table-striped tbody tr:nth-child(odd) {
    background-color: #FAFBFC;
}

.table-container {
    background: var(--white);
    border-radius: var(--radius-md);
    box-shadow: var(--shadow);
    overflow: hidden;
}

.table-container .table {
    margin-bottom: 0;
}

.table-container h3 {
    padding: 20px;
    margin: 0;
    font-size: 18px;
    font-weight: 700;
    border-bottom: 3px solid var(--primary);
}

.table-responsive {
    overflow-x: auto;
    -webkit-overflow-scrolling: touch;
}

.table-actions {
    display: flex;
    gap: 8px;
}

.table-actions .btn {
    padding: 6px 10px;
    font-size: 12px;
}

/* Navigation System */
.main-nav {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    box-shadow: var(--shadow);
}

.nav-category {
    background: rgba(255,255,255,0.15);
    color: var(--white);
    padding: 14px 20px;
    font-size: 15px;
    font-weight: 600;
    cursor: pointer;
    border-radius: var(--radius);
    margin: 8px 0;
    transition: var(--transition);
}

.nav-category:hover {
    background: rgba(255,255,255,0.25);
}

.nav-links {
    display: flex;
    align-items: center;
    padding: 0;
}

.nav-links a {
    color: rgba(255,255,255,0.9);
    padding: 14px 20px;
    font-size: 15px;
    font-weight: 500;
    border-radius: var(--radius);
    margin: 8px 4px;
    transition: var(--transition);
    text-decoration: none;
}

.nav-links a:hover,
.nav-links a.active {
    background: rgba(255,255,255,0.2);
    color: var(--white);
}

/* Admin Sidebar */
.admin-layout {
    display: flex;
    min-height: 100vh;
}

.admin-sidebar {
    width: 260px;
    background: linear-gradient(180deg, var(--dark) 0%, #111827 100%);
    color: var(--white);
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.admin-sidebar .logo {
    padding: 24px 20px;
    text-align: center;
    border-bottom: 1px solid rgba(255,255,255,0.1);
}

.admin-sidebar .logo a {
    color: var(--white);
    font-size: 20px;
    font-weight: 700;
    text-decoration: none;
}

.admin-menu {
    list-style: none;
    padding: 16px 0;
}

.admin-menu li a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 24px;
    color: #9CA3AF;
    transition: var(--transition);
    text-decoration: none;
}

.admin-menu li a:hover,
.admin-menu li a.active {
    background: rgba(255,255,255,0.1);
    color: var(--white);
    border-left: 4px solid var(--primary);
}

.admin-menu li a i {
    width: 20px;
    text-align: center;
}

.admin-content {
    margin-left: 260px;
    flex: 1;
    padding: 24px;
    background: var(--light);
}

.admin-header {
    background: var(--white);
    padding: 16px 24px;
    margin: -24px -24px 24px;
    border-bottom: 1px solid #E5E7EB;
    display: flex;
    justify-content: space-between;
    align-items: center;
    box-shadow: var(--shadow-sm);
}

/* Modal System */
.modal-content {
    border-radius: var(--radius-lg);
    border: none;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    border-bottom: 1px solid #E5E7EB;
    padding: 20px 24px;
}

.modal-header .modal-title {
    font-size: 18px;
    font-weight: 700;
}

.modal-body {
    padding: 24px;
}

.modal-footer {
    border-top: 1px solid #E5E7EB;
    padding: 16px 24px;
}

/* Alert System */
.alert {
    border-radius: var(--radius);
    border: none;
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 12px;
}

.alert i {
    font-size: 20px;
}

.alert-success {
    background: rgba(16, 185, 129, 0.1);
    color: #065F46;
}

.alert-danger {
    background: rgba(239, 68, 68, 0.1);
    color: #991B1B;
}

.alert-warning {
    background: rgba(245, 158, 11, 0.1);
    color: #92400E;
}

.alert-info {
    background: rgba(6, 182, 212, 0.1);
    color: #155E75;
}

/* Tooltips */
.tooltip {
    font-size: 12px;
}

.tooltip-inner {
    background: var(--dark);
    border-radius: var(--radius-sm);
    padding: 8px 12px;
}

/* Responsive Design */
@media (max-width: 1200px) {
    .container {
        max-width: 960px;
    }
}

@media (max-width: 992px) {
    .course-detail-header {
        flex-direction: column;
    }
    
    .course-detail-cover {
        width: 100%;
    }
    
    .school-detail-header {
        flex-direction: column;
        align-items: center;
        text-align: center;
    }
    
    .admin-sidebar {
        width: 80px;
    }
    
    .admin-sidebar .logo a {
        font-size: 0;
    }
    
    .admin-sidebar .logo a::before {
        content: "📚";
        font-size: 24px;
    }
    
    .admin-content {
        margin-left: 80px;
    }
    
    .admin-menu li a span {
        display: none;
    }
}

@media (max-width: 768px) {
    .logo-text {
        font-size: 16px;
    }
    
    .search-box {
        display: none;
    }
    
    .nav-links a {
        padding: 10px 12px;
        font-size: 13px;
    }
    
    .stat-number {
        font-size: 32px;
    }
    
    .feature-icon {
        font-size: 42px;
    }
    
    .course-card .course-cover {
        height: 150px;
    }
    
    .school-card .school-cover {
        height: 120px;
    }
    
    .footer {
        text-align: center;
    }
    
    .footer-links {
        display: inline-block;
        text-align: left;
    }
    
    .footer-social {
        justify-content: center;
    }
}

@media (max-width: 576px) {
    .container {
        padding: 0 15px;
    }
    
    .stat-card {
        padding: 16px;
    }
    
    .course-card .course-info {
        padding: 12px;
    }
    
    .school-card .school-info {
        padding: 12px;
    }
    
    .btn {
        padding: 8px 16px;
        font-size: 13px;
    }
}

/* Animation System */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(20px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.fade-in {
    animation: fadeIn 0.5s ease forwards;
}

@keyframes slideIn {
    from {
        opacity: 0;
        transform: translateX(-20px);
    }
    to {
        opacity: 1;
        transform: translateX(0);
    }
}

.slide-in {
    animation: slideIn 0.5s ease forwards;
}

@keyframes scaleIn {
    from {
        opacity: 0;
        transform: scale(0.9);
    }
    to {
        opacity: 1;
        transform: scale(1);
    }
}

.scale-in {
    animation: scaleIn 0.3s ease forwards;
}

.course-card,
.school-card,
.stat-card {
    animation: fadeIn 0.5s ease forwards;
}

.stagger > *:nth-child(1) { animation-delay: 0.1s; }
.stagger > *:nth-child(2) { animation-delay: 0.2s; }
.stagger > *:nth-child(3) { animation-delay: 0.3s; }
.stagger > *:nth-child(4) { animation-delay: 0.4s; }

.hover-lift {
    transition: transform var(--transition), box-shadow var(--transition);
}

.hover-lift:hover {
    transform: translateY(-4px);
    box-shadow: var(--shadow-lg);
}

.spinner {
    width: 40px;
    height: 40px;
    border: 4px solid var(--light);
    border-top-color: var(--primary);
    border-radius: 50%;
    animation: spin 1s linear infinite;
}

@keyframes spin {
    to {
        transform: rotate(360deg);
    }
}

@keyframes pulse {
    0%, 100% {
        opacity: 1;
    }
    50% {
        opacity: 0.5;
    }
}

.pulse {
    animation: pulse 2s ease-in-out infinite;
}

.logo a { display: flex; align-items: center; }
.logo-icon { font-size: 36px; margin-right: 10px; }
.logo-text {
    font-size: 20px;
    font-weight: 700;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.search-box { padding-top: 6px; }
.search-box .form-control {
    border: 2px solid #E5E7EB;
    border-radius: 25px 0 0 25px;
    padding: 8px 16px;
    transition: var(--transition);
}
.search-box .form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1);
}
.search-box select {
    border: 2px solid #E5E7EB;
    border-right: none;
    border-radius: 25px 0 0 25px;
    padding: 8px 12px;
}
.search-box .btn {
    border-radius: 0 25px 25px 0;
    padding: 8px 18px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    border: none;
}
.user-info { padding-top: 6px; line-height: 32px; }
.user-greeting { color: var(--gray); font-size: 13px; margin-right: 10px; }
.user-info .btn { margin-left: 5px; }
.btn-outline {
    background: transparent;
    border: 1px solid #E5E7EB;
    color: var(--gray);
    border-radius: 20px;
}
.btn-outline:hover { background: var(--light); color: var(--dark); }
.btn-outline-danger {
    background: transparent;
    border: 1px solid var(--danger);
    color: var(--danger);
    border-radius: 20px;
}
.btn-outline-danger:hover { background: var(--danger); color: var(--white); }
.main-nav {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    box-shadow: var(--shadow);
}
.nav-category {
    background: rgba(255,255,255,0.15);
    color: var(--white);
    padding: 12px 18px;
    font-size: 14px;
    font-weight: 600;
    border-radius: var(--radius-sm);
    margin: 6px 0;
}
.nav-links { display: flex; align-items: center; padding: 0; }
.nav-links a {
    color: rgba(255,255,255,0.9);
    padding: 12px 18px;
    font-size: 14px;
    font-weight: 500;
    border-radius: var(--radius-sm);
    margin: 6px 2px;
}
.nav-links a:hover, .nav-links a.active {
    background: rgba(255,255,255,0.2);
    color: var(--white);
}
.stats-section {
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    padding: 45px 0;
    color: var(--white);
    margin: 25px 0;
    border-radius: var(--radius);
    box-shadow: var(--shadow-xl);
}
.stat-item { text-align: center; padding: 15px; }
.stat-number { font-size: 48px; font-weight: 800; margin-bottom: 5px; }
.stat-label { font-size: 15px; opacity: 0.9; }
.feature-section {
    background: var(--white);
    padding: 50px 0;
    margin: 25px 0;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.feature-item {
    text-align: center;
    padding: 25px 15px;
    border-radius: var(--radius);
    transition: var(--transition);
}
.feature-item:hover { transform: translateY(-8px); box-shadow: var(--shadow-xl); }
.feature-icon { font-size: 56px; margin-bottom: 15px; }
.feature-item h4 { margin-bottom: 8px; font-weight: 700; }
.feature-item p { color: var(--gray); font-size: 14px; }
.course-section, .school-section {
    background: var(--white);
    padding: 35px 0;
    margin-bottom: 25px;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}
.section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 25px;
    padding-bottom: 12px;
    border-bottom: 3px solid var(--primary);
}
.section-header h3 { font-size: 24px; font-weight: 700; margin: 0; }
.more-link {
    color: var(--primary);
    font-size: 13px;
    font-weight: 600;
    padding: 6px 14px;
    border: 2px solid var(--primary);
    border-radius: 20px;
}
.more-link:hover { background: var(--primary); color: var(--white); }
.course-card {
    background: var(--white);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    margin-bottom: 20px;
    transition: var(--transition);
    border: 1px solid rgba(0,0,0,0.05);
}
.course-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-xl); }
.course-cover { position: relative; height: 150px; overflow: hidden; }
.course-cover img { width: 100%; height: 100%; object-fit: cover; transition: var(--transition); }
.course-card:hover .course-cover img { transform: scale(1.08); }
.course-cover-placeholder {
    width: 100%; height: 100%;
    background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%);
    display: flex; align-items: center; justify-content: center;
    color: var(--white); font-size: 45px;
}
.course-type {
    position: absolute; top: 0; right: 0;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white); padding: 5px 14px;
    border-bottom-left-radius: 15px; font-size: 11px; font-weight: 600;
}
.course-info { padding: 15px; }
.course-title {
    font-size: 14px; margin-bottom: 10px;
    overflow: hidden; text-overflow: ellipsis; white-space: nowrap;
    font-weight: 600; color: var(--dark);
}
.course-meta { font-size: 11px; color: var(--gray); display: flex; justify-content: space-between; }
.school-card {
    background: var(--white); border-radius: var(--radius);
    overflow: hidden; box-shadow: var(--shadow); margin-bottom: 20px;
    transition: var(--transition); border: 1px solid rgba(0,0,0,0.05);
}
.school-card:hover { transform: translateY(-6px); box-shadow: var(--shadow-xl); }
.school-cover { height: 130px; overflow: hidden; }
.school-cover img { width: 100%; height: 100%; object-fit: cover; transition: var(--transition); }
.school-card:hover .school-cover img { transform: scale(1.08); }
.school-cover-placeholder {
    width: 100%; height: 100%;
    background: linear-gradient(135deg, var(--accent) 0%, #D97706 100%);
    display: flex; align-items: center; justify-content: center;
    color: var(--white); font-size: 40px;
}
.school-info { padding: 15px; }
.school-name { font-size: 14px; margin-bottom: 8px; font-weight: 600; }
.school-meta { font-size: 11px; color: var(--gray); display: flex; justify-content: space-between; }
.rating { color: var(--accent); }
.news-section {
    background: var(--white); padding: 35px 0;
    margin-bottom: 25px; border-radius: var(--radius); box-shadow: var(--shadow);
}
.news-list { list-style: none; padding: 0; }
.news-list li {
    padding: 12px 0; border-bottom: 1px dashed #E5E7EB;
    display: flex; align-items: center; transition: var(--transition);
}
.news-list li:hover { padding-left: 8px; }
.news-date {
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: var(--white); padding: 3px 10px;
    border-radius: 12px; margin-right: 12px; font-size: 11px; font-weight: 600;
}
.news-list a { color: var(--dark); flex: 1; font-weight: 500; }
.login-box {
    background: var(--light); padding: 20px;
    border-radius: var(--radius); box-shadow: var(--shadow);
}
.login-tabs { margin-bottom: 15px; border-bottom: 3px solid var(--primary); padding-bottom: 10px; }
.login-tabs a { font-size: 18px; font-weight: 700; color: var(--primary); }
.footer {
    background: linear-gradient(135deg, var(--dark) 0%, #111827 100%);
    color: var(--white); padding: 45px 0 20px; margin-top: 40px;
}
.footer h4 { margin-bottom: 18px; font-size: 16px; font-weight: 600; }
.footer p { color: #9CA3AF; margin-bottom: 10px; font-size: 13px; }
.footer-links { list-style: none; padding: 0; }
.footer-links li { margin-bottom: 10px; }
.footer-links a { color: #9CA3AF; font-size: 13px; transition: var(--transition); }
.footer-links a:hover { color: var(--white); padding-left: 5px; }
.footer-social { margin-top: 15px; }
.footer-social a {
    display: inline-flex; width: 36px; height: 36px;
    border-radius: 50%; background: rgba(255,255,255,0.1);
    align-items: center; justify-content: center;
    color: var(--white); margin-right: 8px; transition: var(--transition);
}
.footer-social a:hover { background: var(--primary); transform: translateY(-3px); }
.footer-bottom { margin-top: 20px; padding-top: 15px; border-top: 1px solid rgba(255,255,255,0.1); }
.footer-bottom p { font-size: 12px; color: #6B7280; }
.footer-bottom a { color: #9CA3AF; }
.footer-bottom a:hover { color: var(--white); }
.btn { border-radius: 25px; font-weight: 600; padding: 8px 20px; transition: var(--transition); border: none; }
.btn:hover { transform: translateY(-2px); box-shadow: var(--shadow-lg); }
.btn-primary { background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%); color: var(--white); }
.btn-success { background: linear-gradient(135deg, var(--success) 0%, #059669 100%); color: var(--white); }
.btn-danger { background: linear-gradient(135deg, var(--danger) 0%, #DC2626 100%); color: var(--white); }
.btn-warning { background: linear-gradient(135deg, var(--accent) 0%, #D97706 100%); color: var(--white); }
.btn-default { background: var(--light); color: var(--gray); border: 1px solid #E5E7EB; }
.form-control { border: 2px solid #E5E7EB; border-radius: var(--radius-sm); padding: 10px 14px; transition: var(--transition); }
.form-control:focus { border-color: var(--primary); box-shadow: 0 0 0 3px rgba(79, 70, 229, 0.1); }
.course-filter {
    background: var(--white); padding: 20px; margin-bottom: 20px;
    border-radius: var(--radius); box-shadow: var(--shadow);
}
.filter-item { margin-bottom: 12px; display: flex; align-items: flex-start; }
.filter-label { display: inline-block; width: 80px; font-weight: 700; padding-top: 5px; }
.filter-options { display: flex; flex-wrap: wrap; gap: 6px; }
.filter-options a {
    display: inline-block; padding: 6px 14px; border-radius: 18px;
    color: var(--gray); background: var(--light); font-weight: 500; font-size: 13px;
}
.filter-options a:hover, .filter-options a.active {
    background: var(--primary); color: var(--white);
}
.course-detail {
    background: var(--white); padding: 30px;
    border-radius: var(--radius); margin-bottom: 20px; box-shadow: var(--shadow);
}
.course-detail-header { display: flex; gap: 30px; }
.course-detail-cover {
    width: 400px; height: 260px; border-radius: var(--radius);
    overflow: hidden; flex-shrink: 0; box-shadow: var(--shadow-lg);
}
.course-detail-cover img { width: 100%; height: 100%; object-fit: cover; }
.course-detail-info { flex: 1; }
.course-detail-info h1 { font-size: 26px; margin-bottom: 18px; font-weight: 700; }
.course-detail-meta { color: var(--gray); margin-bottom: 18px; display: flex; flex-wrap: wrap; gap: 12px; font-size: 14px; }
.course-detail-meta span { display: flex; align-items: center; gap: 5px; }
.course-detail-desc { color: var(--gray); line-height: 1.8; font-size: 14px; }
.school-detail-header { display: flex; gap: 30px; margin-bottom: 25px; }
.school-detail-logo {
    width: 150px; height: 150px; border-radius: var(--radius);
    overflow: hidden; flex-shrink: 0; box-shadow: var(--shadow-lg);
}
.school-detail-logo img { width: 100%; height: 100%; object-fit: cover; }

@media (max-width: 768px) {
    .admin-sidebar { width: 60px; }
    .admin-sidebar .logo a { font-size: 0; }
    .admin-sidebar .logo a::before { content: "📚"; font-size: 22px; }
    .admin-content { margin-left: 60px; }
}
.table-container {
    background: var(--white); padding: 22px;
    border-radius: var(--radius); box-shadow: var(--shadow);
}
.table-container h3 {
    margin-bottom: 18px; padding-bottom: 10px;
    border-bottom: 3px solid var(--primary); font-weight: 700;
}
.table > thead > tr > th { background: var(--light); border-bottom: 2px solid #E5E7EB; font-weight: 600; padding: 12px 10px; }
.table > tbody > tr > td { padding: 12px 10px; vertical-align: middle; border-bottom: 1px solid #F3F4F6; }
.table > tbody > tr:hover { background: #F9FAFB; }
.stat-card {
    background: var(--white); border-radius: var(--radius);
    padding: 22px; text-align: center; box-shadow: var(--shadow);
    transition: var(--transition); border: 1px solid rgba(0,0,0,0.05);
}
.stat-card:hover { transform: translateY(-4px); box-shadow: var(--shadow-xl); }
.stat-card .stat-icon { font-size: 42px; margin-bottom: 12px; }
.stat-card .stat-value { font-size: 34px; font-weight: 800; color: var(--primary); }
.stat-card .stat-title { color: var(--gray); margin-top: 6px; font-weight: 500; font-size: 13px; }
.label { padding: 4px 10px; border-radius: 12px; font-weight: 600; font-size: 11px; }
.label-success { background: rgba(16,185,129,0.1); color: var(--success); }
.label-danger { background: rgba(239,68,68,0.1); color: var(--danger); }
.label-warning { background: rgba(245,158,11,0.1); color: var(--accent); }
.label-info { background: rgba(6,182,212,0.1); color: var(--secondary); }
.label-default { background: var(--light); color: var(--gray); }
.progress { height: 8px; border-radius: 10px; background: var(--light); overflow: hidden; }
.progress-bar { background: linear-gradient(135deg, var(--primary) 0%, var(--secondary) 100%); border-radius: 10px; }
.breadcrumb-section { background: var(--white); padding: 12px 0; margin-bottom: 20px; box-shadow: var(--shadow); }
.breadcrumb { margin: 0; background: transparent; padding: 0; font-size: 13px; }
.breadcrumb > li + li::before { content: ">"; padding: 0 6px; color: var(--gray); }
.alert { border-radius: var(--radius-sm); border: none; padding: 14px 18px; }
.alert-success { background: rgba(16,185,129,0.1); color: #065F46; }
.alert-danger { background: rgba(239,68,68,0.1); color: #991B1B; }
.alert-warning { background: rgba(245,158,11,0.1); color: #92400E; }
.alert-info { background: rgba(6,182,212,0.1); color: #155E75; }
.pagination > li > a { border-radius: 8px; margin: 0 2px; color: var(--primary); border: 1px solid #E5E7EB; }
.pagination > .active > a { background: var(--primary); border-color: var(--primary); }
.pagination > li > a:hover { background: var(--primary); color: var(--white); }
@keyframes fadeIn { from { opacity: 0; transform: translateY(15px); } to { opacity: 1; transform: translateY(0); } }
.course-card, .school-card, .stat-card { animation: fadeIn 0.4s ease forwards; }
.modal-content { border-radius: var(--radius); border: none; box-shadow: var(--shadow-xl); }
.modal-header { border-bottom: 1px solid #E5E7EB; padding: 18px 22px; }
.modal-footer { border-top: 1px solid #E5E7EB; padding: 14px 22px; }
@media (max-width: 992px) {
    .course-detail-header { flex-direction: column; }
    .course-detail-cover { width: 100%; }
    .school-detail-header { flex-direction: column; align-items: center; text-align: center; }
}
@media (max-width: 768px) {
    .logo-text { font-size: 16px; }
    .search-box { display: none; }
    .nav-links a { padding: 8px 10px; font-size: 12px; }
    .stat-number { font-size: 32px; }
    .feature-icon { font-size: 42px; }
    .admin-sidebar { width: 60px; }
    .admin-sidebar .logo a { font-size: 0; }
    .admin-sidebar .logo a::before { content: "📚"; font-size: 22px; }
    .admin-content { margin-left: 60px; }
    .admin-menu li a span { display: none; }
    .footer { text-align: center; }
    .footer-links { display: inline-block; text-align: left; }
}

/* ========= Global Image Error Fallback ========= */
img[onerror] {
    min-height: 60px;
}
.course-cover-placeholder, .school-logo-placeholder,
span.course-cover-placeholder, span.school-logo-placeholder {
    display: flex;
    align-items: center;
    justify-content: center;
    background: #f0f0f0;
    color: #bbb;
    font-size: 36px;
    min-height: 120px;
}
/* ===== 轮播图增强样式 ===== */
.carousel {
    border-radius: 0;
    margin-bottom: 0;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.15);
}
.carousel-inner {
    border-radius: 0;
}
.carousel-img {
    width: 100%;
    height: 420px;
    object-fit: cover;
}
/* 淡入淡出过渡效果 */
.carousel-fade .item {
    opacity: 0;
    transition: opacity 0.8s ease-in-out;
}
.carousel-fade .item.active {
    opacity: 1;
}
.carousel-fade .item.active.left,
.carousel-fade .item.active.right {
    opacity: 0;
}
.carousel-fade .item.next,
.carousel-fade .item.prev {
    opacity: 1;
}
/* 指示器 */
.carousel-indicators {
    bottom: 20px;
    z-index: 15;
}
.carousel-indicators li {
    width: 12px;
    height: 12px;
    border-radius: 50%;
    border: 2px solid rgba(255,255,255,0.9);
    background: transparent;
    margin: 0 5px;
    transition: all 0.3s ease;
}
.carousel-indicators li.active {
    width: 14px;
    height: 14px;
    background: #fff;
    border-color: #fff;
    transform: scale(1.1);
}
/* 控制箭头 */
.carousel-control {
    width: 50px;
    height: 50px;
    top: 50%;
    margin-top: -25px;
    background: rgba(0,0,0,0.25);
    border-radius: 50%;
    transition: all 0.3s ease;
    opacity: 0;
    text-shadow: none;
}
.carousel:hover .carousel-control {
    opacity: 1;
}
.carousel-control:hover {
    background: rgba(0,0,0,0.5);
}
.carousel-control.left {
    left: 20px;
}
.carousel-control.right {
    right: 20px;
}
.carousel-control .glyphicon-chevron-left,
.carousel-control .glyphicon-chevron-right {
    position: absolute;
    top: 50%;
    margin-top: -10px;
    font-size: 20px;
}
.carousel-control .glyphicon-chevron-left {
    left: 50%;
    margin-left: -6px;
}
.carousel-control .glyphicon-chevron-right {
    right: 50%;
    margin-right: -6px;
}
/* 轮播图标题浮层 */
.carousel-caption {
    position: absolute;
    bottom: 60px;
    left: 0;
    right: 0;
    padding: 20px 30px;
    background: linear-gradient(transparent 0%, rgba(0,0,0,0.5) 100%);
    border-radius: 0;
    text-shadow: 0 2px 4px rgba(0,0,0,0.5);
    opacity: 0;
    transition: opacity 0.6s ease;
    text-align: center;
}
.carousel-caption .caption-title {
    font-size: 28px;
    font-weight: 700;
    margin: 0 0 5px;
    color: #fff;
}
.carousel-caption .caption-desc {
    font-size: 16px;
    opacity: 0.9;
    margin: 0;
    color: #fff;
}
/* Banner fallback 默认背景 */
.banner-default {
    width: 100%;
    height: 420px;
    background: linear-gradient(135deg, #4F46E5 0%, #06B6D4 100%);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
}
.banner-default-inner {
    text-align: center;
}
.banner-default-inner h2 {
    font-size: 36px;
    font-weight: 700;
    margin-bottom: 10px;
    color: #fff;
}
.banner-default-inner p {
    font-size: 18px;
    opacity: 0.9;
    color: #fff;
}
/* 演示用卡片半透明标识 */
.demo-card {
    position: relative;
}
.demo-card::after {
    content: '示例';
    position: absolute;
    top: 8px;
    left: 8px;
    background: rgba(245,158,11,0.85);
    color: #fff;
    padding: 2px 8px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 600;
    z-index: 2;
}
/* 示例新闻日期 */
.demo-date {
    opacity: 0.7;
}
/* 响应式轮播高度 */
@media (max-width: 992px) {
    .carousel-img,
    .banner-fallback,
    .banner-default {
        height: 320px !important;
    }
    .carousel-caption .caption-title {
        font-size: 22px;
    }
    .banner-default-inner h2 {
        font-size: 28px;
    }
}
@media (max-width: 768px) {
    .carousel-img,
    .banner-fallback,
    .banner-default {
        height: 240px !important;
    }
    .carousel-caption {
        bottom: 40px;
        padding: 12px 15px;
    }
    .carousel-caption .caption-title {
        font-size: 18px;
    }
    .carousel-caption .caption-desc {
        font-size: 13px;
    }
    .banner-default-inner h2 {
        font-size: 22px;
    }
    .banner-default-inner p {
        font-size: 14px;
    }
    .carousel-indicators {
        bottom: 10px;
    }
    .carousel-indicators li {
        width: 8px;
        height: 8px;
        margin: 0 3px;
    }
    .carousel-control {
        width: 36px;
        height: 36px;
        margin-top: -18px;
    }
    .carousel-control .glyphicon-chevron-left,
    .carousel-control .glyphicon-chevron-right {
        font-size: 14px;
    }
}
@media (max-width: 576px) {
    .carousel-img,
    .banner-fallback,
    .banner-default {
        height: 180px !important;
    }
    .carousel-caption {
        bottom: 30px;
        padding: 8px 12px;
    }
    .carousel-caption .caption-title {
        font-size: 15px;
        margin-bottom: 0;
    }
    .carousel-caption .caption-desc {
        font-size: 11px;
    }
    .banner-default-inner h2 {
        font-size: 18px;
    }
    .banner-default-inner i.fa-graduation-cap {
        font-size: 40px !important;
    }
    .banner-default-inner p {
        font-size: 12px;
    }
}
/* ===== 返回顶部按钮 ===== */
.back-to-top {
    position: fixed;
    bottom: 30px;
    right: 30px;
    width: 44px;
    height: 44px;
    border-radius: 50%;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    border: none;
    box-shadow: 0 4px 15px rgba(79,70,229,0.4);
    cursor: pointer;
    opacity: 0;
    visibility: hidden;
    transform: translateY(20px);
    transition: all 0.3s ease;
    z-index: 999;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
}
.back-to-top.show {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}
.back-to-top:hover {
    transform: translateY(-4px);
    box-shadow: 0 6px 20px rgba(79,70,229,0.6);
}

/* ===== 滚动动画 ===== */
.scroll-animate {
    opacity: 0;
    transform: translateY(30px);
    transition: all 0.6s ease;
}
.scroll-animate.animated.fadeInUp {
    opacity: 1;
    transform: translateY(0);
}

/* ===== 统计区域图标 ===== */
.stat-icon-big {
    font-size: 42px;
    margin-bottom: 12px;
    display: block;
    opacity: 0.9;
}

/* ===== 移动端按钮 ===== */
.mobile-search-btn,
.mobile-menu-btn {
    padding: 6px 10px !important;
    margin-left: 4px !important;
    border-radius: 50% !important;
    width: 34px;
    height: 34px;
    display: inline-flex !important;
    align-items: center;
    justify-content: center;
}

/* ===== 导航栏移动端适配 ===== */
@media (max-width: 991px) {
    .main-nav {
        display: none;
    }
    .main-nav .nav-category {
        text-align: center;
    }
    .main-nav .nav-links {
        justify-content: center;
        flex-wrap: wrap;
    }
    .main-nav .nav-links a {
        padding: 10px 14px;
        font-size: 13px;
    }
}

/* ===== 输入框图标 ===== */
.input-icon {
    position: relative;
}
.input-icon .form-control {
    padding-left: 40px;
}
.input-icon i {
    position: absolute;
    left: 14px;
    top: 50%;
    transform: translateY(-50%);
    color: #9CA3AF;
    font-size: 15px;
}

/* ===== 登录框美化 ===== */
.login-box {
    position: relative;
    overflow: hidden;
}
.login-box::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary), var(--accent));
}
.login-box .btn-block {
    border-radius: 25px;
    padding: 12px;
    font-weight: 600;
}
.login-footer {
    margin-top: 15px;
    font-size: 13px;
}
.login-footer a {
    color: var(--primary);
    font-weight: 500;
}
.login-footer a:hover {
    color: var(--primary-dark);
}

/* ===== Section标题图标 ===== */
.section-header h3 i {
    margin-right: 8px;
    color: var(--primary);
}

/* ===== 新闻列表图标 ===== */
.news-list li a i {
    margin-right: 6px;
    color: var(--gray);
    font-size: 13px;
}
.news-date i {
    margin-right: 4px;
    font-size: 11px;
}

/* ===== demo卡片徽标增强 ===== */
.demo-card::after {
    background: linear-gradient(135deg, #F59E0B, #D97706);
    box-shadow: 0 2px 6px rgba(245,158,11,0.3);
}

/* ===== 按钮hover微调 ===== */
.btn-primary i,
.btn-success i,
.btn-danger i,
.btn-warning i {
    margin-right: 4px;
}

/* ===== 导航图标间距 ===== */
.nav-links a i {
    margin-right: 5px;
}

/* ===== 移动端搜索条 ===== */
.mobile-search-bar .input-group {
    display: flex;
    gap: 6px;
}
.mobile-search-bar .input-group select {
    width: auto;
    border-radius: 20px;
}
.mobile-search-bar .input-group input {
    border-radius: 20px;
    flex: 1;
}
.mobile-search-bar .input-group .btn {
    border-radius: 50%;
    width: 38px;
    height: 38px;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
}

/* ===== 页面加载占位动画 ===== */
@keyframes shimmer {
    0% { background-position: -200% 0; }
    100% { background-position: 200% 0; }
}
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: shimmer 1.5s infinite;
    border-radius: 6px;
}

/* ================================================================
   ===== 第二轮深度美化：统计卡片动画 =====
   ================================================================ */

/* 各统计卡片不同渐变背景 */
.stat-item.stat-blue {
    background: linear-gradient(135deg, #3B82F6 0%, #1D4ED8 100%);
    border-radius: var(--radius);
    box-shadow: 0 8px 25px rgba(59,130,246,0.3);
}
.stat-item.stat-purple {
    background: linear-gradient(135deg, #8B5CF6 0%, #6D28D9 100%);
    border-radius: var(--radius);
    box-shadow: 0 8px 25px rgba(139,92,246,0.3);
}
.stat-item.stat-cyan {
    background: linear-gradient(135deg, #06B6D4 0%, #0891B2 100%);
    border-radius: var(--radius);
    box-shadow: 0 8px 25px rgba(6,182,212,0.3);
}
.stat-item.stat-orange {
    background: linear-gradient(135deg, #F59E0B 0%, #D97706 100%);
    border-radius: var(--radius);
    box-shadow: 0 8px 25px rgba(245,158,11,0.3);
}
.stat-item:hover {
    transform: translateY(-8px) scale(1.02);
    box-shadow: 0 16px 40px rgba(0,0,0,0.25) !important;
}
.stat-item {
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275) !important;
    cursor: default;
    position: relative;
    overflow: hidden;
}
.stat-item::after {
    content: '';
    position: absolute;
    top: -50%;
    left: -50%;
    width: 200%;
    height: 200%;
    background: radial-gradient(circle, rgba(255,255,255,0.1) 0%, transparent 60%);
    opacity: 0;
    transition: opacity 0.6s ease;
    pointer-events: none;
}
.stat-item:hover::after {
    opacity: 1;
}

/* 统计图标跳动动画 */
.stat-icon-big {
    display: inline-block;
    transition: transform 0.4s ease;
}
.stat-item:hover .stat-icon-big {
    animation: iconBounce 0.6s ease;
}

@keyframes iconBounce {
    0%, 100% { transform: translateY(0); }
    30% { transform: translateY(-12px) scale(1.1); }
    60% { transform: translateY(-5px); }
}

/* ===== 课程卡片增强 ===== */
.course-card {
    position: relative;
    overflow: hidden;
}
/* 图片加载失败占位增强 */
.course-cover-placeholder,
.cover-fallback {
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 45px;
    color: white;
}
.cover-fallback {
    background: linear-gradient(135deg, #4F46E5, #06B6D4);
}

/* 课程封面渐变遮罩（hover时显示） */
.course-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(to top, rgba(0,0,0,0.85) 0%, rgba(0,0,0,0.2) 50%, transparent 100%);
    display: flex;
    flex-direction: column;
    justify-content: flex-end;
    padding: 16px;
    opacity: 0;
    transition: opacity 0.35s ease;
    z-index: 3;
}
.course-card:hover .course-overlay {
    opacity: 1;
}
.course-overlay p {
    color: rgba(255,255,255,0.9);
    font-size: 12px;
    line-height: 1.5;
    margin: 0;
    overflow: hidden;
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
}

/* 课程标签角标 */
.course-badge {
    position: absolute;
    top: 10px;
    left: 10px;
    z-index: 4;
    padding: 3px 10px;
    border-radius: 4px;
    font-size: 11px;
    font-weight: 700;
    color: #fff;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.2);
}
.course-badge.hot {
    background: linear-gradient(135deg, #EF4444, #DC2626);
}
.course-badge.free {
    background: linear-gradient(135deg, #10B981, #059669);
}
.course-badge.new {
    background: linear-gradient(135deg, #3B82F6, #2563EB);
}

/* 课程难度标识 */
.course-difficulty {
    display: flex;
    align-items: center;
    gap: 4px;
    font-size: 11px;
    color: var(--gray);
}
.course-difficulty .diff-bar {
    display: flex;
    gap: 2px;
}
.course-difficulty .diff-bar span {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: #E5E7EB;
    transition: background 0.3s ease;
}
.course-difficulty .diff-bar span.filled {
    background: var(--primary);
}
.course-difficulty .diff-bar span.filled.easy { background: #10B981; }
.course-difficulty .diff-bar span.filled.medium { background: #F59E0B; }
.course-difficulty .diff-bar span.filled.hard { background: #EF4444; }

/* ===== 平台特色卡片增强 ===== */
.feature-item {
    position: relative;
    overflow: hidden;
    padding-bottom: 30px;
}
/* 各卡片主题色 */
.feature-item.feat-blue .feature-icon { color: #3B82F6; }
.feature-item.feat-green .feature-icon { color: #10B981; }
.feature-item.feat-purple .feature-icon { color: #8B5CF6; }

/* 图标圆形渐变背景 */
.feature-item .feature-icon {
    width: 80px;
    height: 80px;
    line-height: 80px;
    border-radius: 50%;
    margin: 0 auto 15px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 32px;
    transition: all 0.5s ease;
    position: relative;
}
.feature-item.feat-blue .feature-icon {
    background: linear-gradient(135deg, rgba(59,130,246,0.12), rgba(59,130,246,0.05));
    color: #3B82F6;
    box-shadow: 0 4px 15px rgba(59,130,246,0.15);
}
.feature-item.feat-green .feature-icon {
    background: linear-gradient(135deg, rgba(16,185,129,0.12), rgba(16,185,129,0.05));
    color: #10B981;
    box-shadow: 0 4px 15px rgba(16,185,129,0.15);
}
.feature-item.feat-purple .feature-icon {
    background: linear-gradient(135deg, rgba(139,92,246,0.12), rgba(139,92,246,0.05));
    color: #8B5CF6;
    box-shadow: 0 4px 15px rgba(139,92,246,0.15);
}

/* hover图标旋转/跳动 */
.feature-item:hover .feature-icon {
    transform: rotateY(180deg) scale(1.1);
}
.feature-item.feat-blue:hover .feature-icon {
    background: linear-gradient(135deg, rgba(59,130,246,0.2), rgba(59,130,246,0.1));
    box-shadow: 0 6px 25px rgba(59,130,246,0.25);
}
.feature-item.feat-green:hover .feature-icon {
    background: linear-gradient(135deg, rgba(16,185,129,0.2), rgba(16,185,129,0.1));
    box-shadow: 0 6px 25px rgba(16,185,129,0.25);
}
.feature-item.feat-purple:hover .feature-icon {
    background: linear-gradient(135deg, rgba(139,92,246,0.2), rgba(139,92,246,0.1));
    box-shadow: 0 6px 25px rgba(139,92,246,0.25);
}

/* 卡片底部装饰线 */
.feature-item::before {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 40px;
    height: 4px;
    border-radius: 2px;
    transition: all 0.4s ease;
}
.feature-item.feat-blue::before { background: linear-gradient(90deg, #3B82F6, #60A5FA); }
.feature-item.feat-green::before { background: linear-gradient(90deg, #10B981, #34D399); }
.feature-item.feat-purple::before { background: linear-gradient(90deg, #8B5CF6, #A78BFA); }
.feature-item:hover::before {
    width: 80px;
}

/* Hover卡片上浮增强 */
.feature-item:hover {
    transform: translateY(-8px);
    box-shadow: var(--shadow-xl);
}

/* ===== 培训机构卡片美化 ===== */
.school-card {
    position: relative;
}
/* 不同学校logo加载失败时不同颜色 */
.school-card:nth-child(1) .school-cover-placeholder,
.school-card:nth-child(1) .scover-fallback {
    background: linear-gradient(135deg, #3B82F6, #1D4ED8) !important;
}
.school-card:nth-child(2) .school-cover-placeholder,
.school-card:nth-child(2) .scover-fallback {
    background: linear-gradient(135deg, #8B5CF6, #6D28D9) !important;
}
.school-card:nth-child(3) .school-cover-placeholder,
.school-card:nth-child(3) .scover-fallback {
    background: linear-gradient(135deg, #06B6D4, #0891B2) !important;
}
.school-card:nth-child(4) .school-cover-placeholder,
.school-card:nth-child(4) .scover-fallback {
    background: linear-gradient(135deg, #F59E0B, #D97706) !important;
}

/* 评级星星金色 */
.school-meta .rating {
    color: #F59E0B;
    font-size: 13px;
    letter-spacing: 2px;
}
.school-meta .rating .fa-star-o {
    color: #D1D5DB;
}

/* "查看课程"快捷按钮 */
.school-card .school-action {
    display: block;
    text-align: center;
    padding: 8px 12px;
    margin: 0 15px 15px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    transition: all 0.3s ease;
    opacity: 0;
    transform: translateY(5px);
}
.school-card:hover .school-action {
    opacity: 1;
    transform: translateY(0);
}
.school-card .school-action:hover {
    box-shadow: 0 4px 15px rgba(79,70,229,0.4);
    transform: translateY(-2px);
}

/* ================================================================
   ===== UI 优化：现代培训平台风格 =====
   ================================================================ */

/* 首页英雄区域增强 */
.hero-section {
    position: relative;
    background: linear-gradient(135deg, #1e3a5f 0%, #0d2137 50%, #1a365d 100%);
    padding: 80px 0 60px;
    overflow: hidden;
}
.hero-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="0.5"/></svg>') repeat;
    background-size: 100px;
    animation: heroFloat 20s linear infinite;
}
@keyframes heroFloat {
    0% { background-position: 0 0; }
    100% { background-position: 100px 100px; }
}
.hero-content {
    position: relative;
    z-index: 1;
    text-align: center;
    color: white;
}
.hero-content h1 {
    font-size: 42px;
    font-weight: 800;
    margin-bottom: 20px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}
.hero-content p {
    font-size: 18px;
    opacity: 0.9;
    max-width: 600px;
    margin: 0 auto 30px;
}

/* 现代化登录卡片 */
.login-card {
    background: white;
    border-radius: 20px;
    box-shadow: 0 20px 60px rgba(0,0,0,0.15);
    overflow: hidden;
    transition: transform 0.3s ease;
}
.login-card:hover {
    transform: translateY(-5px);
}
.login-card-header {
    background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
    padding: 30px;
    text-align: center;
    color: white;
}
.login-card-header h2 {
    margin: 0;
    font-size: 24px;
    font-weight: 700;
}
.login-card-header p {
    margin: 10px 0 0;
    opacity: 0.9;
    font-size: 14px;
}
.login-card-body {
    padding: 30px;
}

/* 增强的课程卡片 */
.course-card-v2 {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.4s cubic-bezier(0.175, 0.885, 0.32, 1.275);
    position: relative;
}
.course-card-v2:hover {
    transform: translateY(-12px) scale(1.02);
    box-shadow: 0 20px 40px rgba(0,0,0,0.15);
}
.course-card-v2 .cover {
    position: relative;
    height: 200px;
    overflow: hidden;
}
.course-card-v2 .cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
    transition: transform 0.5s ease;
}
.course-card-v2:hover .cover img {
    transform: scale(1.1);
}
.course-card-v2 .cover-overlay {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: linear-gradient(to top, rgba(0,0,0,0.7) 0%, transparent 50%);
    opacity: 0;
    transition: opacity 0.3s ease;
}
.course-card-v2:hover .cover-overlay {
    opacity: 1;
}
.course-card-v2 .badge {
    position: absolute;
    top: 15px;
    left: 15px;
    padding: 6px 14px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    color: white;
    z-index: 2;
}
.course-card-v2 .badge.hot {
    background: linear-gradient(135deg, #EF4444, #DC2626);
}
.course-card-v2 .badge.free {
    background: linear-gradient(135deg, #10B981, #059669);
}
.course-card-v2 .badge.new {
    background: linear-gradient(135deg, #3B82F6, #2563EB);
}
.course-card-v2 .content {
    padding: 20px;
}
.course-card-v2 .title {
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
    margin-bottom: 10px;
    line-height: 1.4;
}
.course-card-v2 .meta {
    display: flex;
    align-items: center;
    gap: 15px;
    font-size: 13px;
    color: #6B7280;
}
.course-card-v2 .meta span {
    display: flex;
    align-items: center;
    gap: 5px;
}
.course-card-v2 .footer {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    border-top: 1px solid #F3F4F6;
}

/* 增强的统计卡片 */
.stat-card-v2 {
    background: white;
    border-radius: 16px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}
.stat-card-v2::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
}
.stat-card-v2:hover {
    transform: translateY(-8px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.15);
}
.stat-card-v2 .icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    transition: transform 0.4s ease;
}
.stat-card-v2:hover .icon {
    transform: scale(1.1) rotate(5deg);
}
.stat-card-v2 .icon.blue {
    background: linear-gradient(135deg, rgba(59,130,246,0.15), rgba(59,130,246,0.05));
    color: #3B82F6;
}
.stat-card-v2 .icon.purple {
    background: linear-gradient(135deg, rgba(139,92,246,0.15), rgba(139,92,246,0.05));
    color: #8B5CF6;
}
.stat-card-v2 .icon.cyan {
    background: linear-gradient(135deg, rgba(6,182,212,0.15), rgba(6,182,212,0.05));
    color: #06B6D4;
}
.stat-card-v2 .icon.orange {
    background: linear-gradient(135deg, rgba(245,158,11,0.15), rgba(245,158,11,0.05));
    color: #F59E0B;
}
.stat-card-v2 .value {
    font-size: 42px;
    font-weight: 800;
    color: #1F2937;
    margin-bottom: 8px;
    background: linear-gradient(135deg, #1F2937, #4B5563);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-card-v2 .label {
    font-size: 14px;
    color: #6B7280;
    font-weight: 500;
}

/* 特色功能卡片 */
.feature-card {
    background: white;
    border-radius: 16px;
    padding: 35px 25px;
    text-align: center;
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
    transition: all 0.4s ease;
    position: relative;
    overflow: hidden;
}
.feature-card::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 50%;
    transform: translateX(-50%);
    width: 0;
    height: 4px;
    border-radius: 2px;
    transition: width 0.4s ease;
}
.feature-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 16px 40px rgba(0,0,0,0.12);
}
.feature-card:hover::after {
    width: 60%;
}
.feature-card.blue::after { background: linear-gradient(90deg, #3B82F6, #60A5FA); }
.feature-card.green::after { background: linear-gradient(90deg, #10B981, #34D399); }
.feature-card.purple::after { background: linear-gradient(90deg, #8B5CF6, #A78BFA); }
.feature-card .icon-wrapper {
    width: 90px;
    height: 90px;
    margin: 0 auto 20px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    transition: all 0.5s ease;
}
.feature-card:hover .icon-wrapper {
    transform: rotateY(180deg);
}
.feature-card.blue .icon-wrapper {
    background: linear-gradient(135deg, rgba(59,130,246,0.12), rgba(59,130,246,0.05));
    color: #3B82F6;
    box-shadow: 0 4px 20px rgba(59,130,246,0.2);
}
.feature-card.green .icon-wrapper {
    background: linear-gradient(135deg, rgba(16,185,129,0.12), rgba(16,185,129,0.05));
    color: #10B981;
    box-shadow: 0 4px 20px rgba(16,185,129,0.2);
}
.feature-card.purple .icon-wrapper {
    background: linear-gradient(135deg, rgba(139,92,246,0.12), rgba(139,92,246,0.05));
    color: #8B5CF6;
    box-shadow: 0 4px 20px rgba(139,92,246,0.2);
}
.feature-card h3 {
    font-size: 20px;
    font-weight: 700;
    color: #1F2937;
    margin-bottom: 12px;
}
.feature-card p {
    font-size: 14px;
    color: #6B7280;
    line-height: 1.6;
    margin: 0;
}

/* 增强的新闻卡片 */
.news-card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 15px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
    border-left: 4px solid transparent;
}
.news-card:hover {
    transform: translateX(5px);
    border-left-color: var(--primary);
    box-shadow: 0 4px 20px rgba(0,0,0,0.1);
}
.news-card .date {
    display: inline-block;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    padding: 4px 12px;
    border-radius: 15px;
    font-size: 12px;
    font-weight: 600;
    margin-bottom: 10px;
}
.news-card .title {
    font-size: 15px;
    font-weight: 600;
    color: #1F2937;
    margin: 0;
    transition: color 0.3s ease;
}
.news-card:hover .title {
    color: var(--primary);
}

/* 现代化表格 */
.table-v2 {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.table-v2 thead {
    background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
}
.table-v2 th {
    padding: 16px 20px;
    font-size: 13px;
    font-weight: 600;
    color: #475569;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    border-bottom: 2px solid #E2E8F0;
}
.table-v2 td {
    padding: 16px 20px;
    font-size: 14px;
    color: #334155;
    border-bottom: 1px solid #F1F5F9;
}
.table-v2 tbody tr {
    transition: all 0.3s ease;
}
.table-v2 tbody tr:hover {
    background: #F8FAFC;
}
.table-v2 tbody tr:last-child td {
    border-bottom: none;
}

/* 增强的按钮 */
.btn-v2 {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 12px 24px;
    font-size: 14px;
    font-weight: 600;
    border-radius: 12px;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}
.btn-v2:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.15);
}
.btn-v2.primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.btn-v2.secondary {
    background: linear-gradient(135deg, #06B6D4, #0891B2);
    color: white;
}
.btn-v2.success {
    background: linear-gradient(135deg, #10B981, #059669);
    color: white;
}
.btn-v2.danger {
    background: linear-gradient(135deg, #EF4444, #DC2626);
    color: white;
}

/* 面包屑增强 */
.breadcrumb-v2 {
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 12px 0;
    font-size: 13px;
    color: #6B7280;
}
.breadcrumb-v2 a {
    color: #4F46E5;
    text-decoration: none;
    transition: color 0.3s ease;
}
.breadcrumb-v2 a:hover {
    color: #3730A3;
}
.breadcrumb-v2 .separator {
    color: #D1D5DB;
}

/* 分页增强 */
.pagination-v2 {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 30px;
}
.pagination-v2 a,
.pagination-v2 span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    width: 40px;
    height: 40px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    border: 1px solid #E5E7EB;
    color: #4B5563;
    background: white;
}
.pagination-v2 a:hover {
    background: #4F46E5;
    color: white;
    border-color: #4F46E5;
    transform: translateY(-2px);
}
.pagination-v2 .active {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border-color: transparent;
    box-shadow: 0 4px 12px rgba(79,70,229,0.3);
}

/* 加载动画 */
.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid #E5E7EB;
    border-top-color: #4F46E5;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 空状态 */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #9CA3AF;
}
.empty-state .icon {
    font-size: 64px;
    margin-bottom: 20px;
    opacity: 0.5;
}
.empty-state h3 {
    font-size: 20px;
    font-weight: 600;
    color: #6B7280;
    margin-bottom: 10px;
}
.empty-state p {
    font-size: 14px;
    margin-bottom: 20px;
}

/* 徽章增强 */
.badge-v2 {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}
.badge-v2.success {
    background: rgba(16,185,129,0.1);
    color: #059669;
}
.badge-v2.danger {
    background: rgba(239,68,68,0.1);
    color: #DC2626;
}
.badge-v2.warning {
    background: rgba(245,158,11,0.1);
    color: #D97706;
}
.badge-v2.info {
    background: rgba(6,182,212,0.1);
    color: #0891B2;
}

/* 进度条增强 */
.progress-v2 {
    height: 10px;
    border-radius: 10px;
    background: #E5E7EB;
    overflow: hidden;
}
.progress-v2 .bar {
    height: 100%;
    border-radius: 10px;
    background: linear-gradient(90deg, #4F46E5, #7C3AED);
    transition: width 0.5s ease;
}

/* 卡片头部 */
.card-header-v2 {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px;
    border-bottom: 1px solid #E5E7EB;
}
.card-header-v2 h3 {
    margin: 0;
    font-size: 18px;
    font-weight: 700;
    color: #1F2937;
}

/* 表单组增强 */
.form-group-v2 {
    margin-bottom: 24px;
}
.form-group-v2 label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 600;
    color: #374151;
}
.form-group-v2 .hint {
    font-size: 12px;
    color: #9CA3AF;
    margin-top: 6px;
}

/* 输入框增强 */
.input-v2 {
    width: 100%;
    padding: 14px 16px;
    font-size: 14px;
    border: 2px solid #E5E7EB;
    border-radius: 12px;
    transition: all 0.3s ease;
    background: white;
}
.input-v2:focus {
    outline: none;
    border-color: #4F46E5;
    box-shadow: 0 0 0 4px rgba(79,70,229,0.1);
}
.input-v2::placeholder {
    color: #9CA3AF;
}

/* 移动端优化 */
@media (max-width: 768px) {
    .hero-content h1 {
        font-size: 28px;
    }
    .hero-content p {
        font-size: 15px;
    }
    .stat-card-v2 {
        padding: 20px;
    }
    .stat-card-v2 .value {
        font-size: 32px;
    }
    .feature-card {
        padding: 25px 20px;
    }
    .feature-card .icon-wrapper {
        width: 70px;
        height: 70px;
        font-size: 28px;
    }
}

/* ===== 新闻列表美化 ===== */
.news-list li {
    position: relative;
    padding-left: 20px;
    border-bottom: 1px solid #F3F4F6;
}
/* 左侧竖条颜色装饰 */
.news-list li::before {
    content: '';
    position: absolute;
    left: 0;
    top: 8px;
    bottom: 8px;
    width: 4px;
    border-radius: 2px;
    transition: all 0.3s ease;
}
.news-list li:nth-child(1)::before { background: #3B82F6; }
.news-list li:nth-child(2)::before { background: #8B5CF6; }
.news-list li:nth-child(3)::before { background: #06B6D4; }
.news-list li:nth-child(4)::before { background: #10B981; }
.news-list li:nth-child(5)::before { background: #F59E0B; }
.news-list li:nth-child(6)::before { background: #EF4444; }
.news-list li:nth-child(7)::before { background: #3B82F6; }
.news-list li:nth-child(8)::before { background: #8B5CF6; }

/* 悬停时左侧变色加深 */
.news-list li:hover::before {
    width: 6px;
    filter: brightness(1.2);
}
.news-list li:hover {
    background: linear-gradient(90deg, rgba(79,70,229,0.03), transparent);
    padding-left: 22px;
}

/* 日期标签美化 */
.news-date {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 600;
    white-space: nowrap;
    box-shadow: 0 2px 8px rgba(79,70,229,0.2);
    transition: all 0.3s ease;
}
.news-list li:hover .news-date {
    transform: scale(1.05);
    box-shadow: 0 3px 12px rgba(79,70,229,0.3);
}
.demo-date {
    opacity: 0.85;
}

/* ===== 登录框增强 ===== */
.login-box {
    position: relative;
    border-radius: var(--radius-md);
    transition: all 0.3s ease;
}
.login-box:hover {
    box-shadow: var(--shadow-lg);
}

/* 更优雅的输入框样式 */
.login-box .input-icon .form-control {
    border-radius: 12px;
    padding: 12px 16px 12px 44px;
    border: 2px solid #E5E7EB;
    background: #FAFBFC;
    transition: all 0.3s ease;
    font-size: 14px;
    box-shadow: inset 0 2px 4px rgba(0,0,0,0.02);
}
.login-box .input-icon .form-control:focus {
    border-color: var(--primary);
    box-shadow: 0 0 0 4px rgba(79,70,229,0.1), inset 0 2px 4px rgba(0,0,0,0.02);
    background: var(--white);
    transform: translateY(-1px);
}
.login-box .input-icon .form-control::placeholder {
    color: #B0B7C3;
    font-weight: 400;
}
.login-box .input-icon i {
    left: 16px;
    color: #9CA3AF;
    transition: color 0.3s ease;
    font-size: 16px;
}
.login-box .input-icon:focus-within i {
    color: var(--primary);
}

/* 登录按钮hover渐变增强 */
.login-box .btn-block {
    border-radius: 12px;
    padding: 12px 20px;
    font-weight: 700;
    font-size: 15px;
    letter-spacing: 0.5px;
    background: linear-gradient(135deg, var(--primary) 0%, #7C3AED 100%);
    transition: all 0.35s ease;
    position: relative;
    overflow: hidden;
}
.login-box .btn-block::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #7C3AED 0%, var(--primary) 100%);
    opacity: 0;
    transition: opacity 0.35s ease;
}
.login-box .btn-block:hover::before {
    opacity: 1;
}
.login-box .btn-block:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 25px rgba(79,70,229,0.4);
}
.login-box .btn-block:active {
    transform: translateY(-1px);
}
.login-box .btn-block i,
.login-box .btn-block span {
    position: relative;
    z-index: 1;
}
.login-box .btn-block i {
    margin-right: 6px;
}

/* 注册链接按钮样式 */
.login-footer .register-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 18px;
    border-radius: 25px;
    background: linear-gradient(135deg, #10B981, #059669);
    color: #fff;
    font-weight: 600;
    font-size: 13px;
    transition: all 0.3s ease;
    box-shadow: 0 4px 12px rgba(16,185,129,0.3);
}
.login-footer .register-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(16,185,129,0.4);
    color: #fff;
    text-decoration: none;
}

/* ===== 全局平滑滚动 ===== */
html {
    scroll-behavior: smooth;
}

/* ===== 全局过渡动画增强 ===== */
* {
    transition-property: background-color, border-color, color, fill, stroke, opacity, box-shadow, transform;
    transition-duration: 200ms;
    transition-timing-function: ease;
}

/* 所有图片懒加载 */
img {
    loading: lazy;
}

/* 所有卡片统一过渡动画 */
.course-card,
.school-card,
.feature-item,
.stat-item,
.news-list li,
.login-box {
    transition: all 0.35s cubic-bezier(0.4, 0, 0.2, 1) !important;
}

/* 导航栏滚动阴影增强 */
.header {
    transition: box-shadow 0.3s ease, padding 0.3s ease !important;
}
.header.scrolled {
    box-shadow: 0 4px 20px rgba(0,0,0,0.12);
    padding: 6px 0;
}

/* Section进入动画增强 */
.scroll-animate {
    transition: all 0.7s cubic-bezier(0.22, 1, 0.36, 1);
}
.scroll-animate.animated.fadeInUp {
    animation: fadeInUp 0.7s cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

@keyframes fadeInUp {
    from {
        opacity: 0;
        transform: translateY(40px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

/* 全局hover卡片阴影统一 */
.course-card:hover,
.school-card:hover {
    transform: translateY(-8px);
    box-shadow: 0 20px 40px rgba(0,0,0,0.12), 0 8px 16px rgba(0,0,0,0.06);
}

/* 查看更多课程按钮美化 */
.btn-view-more {
    padding: 12px 48px;
    border-radius: 30px;
    font-weight: 700;
    font-size: 15px;
    background: linear-gradient(135deg, var(--primary) 0%, var(--primary-dark) 100%);
    color: #fff;
    border: none;
    transition: all 0.35s ease;
    box-shadow: 0 4px 15px rgba(79,70,229,0.3);
}
.btn-view-more:hover {
    transform: translateY(-3px);
    box-shadow: 0 8px 30px rgba(79,70,229,0.45);
    color: #fff;
}

/* section之间间距微调 */
.stats-section,
.feature-section,
.course-section,
.school-section,
.news-section {
    margin: 30px 0;
}

/* 响应式调整：小屏隐藏部分装饰效果 */
@media (max-width: 768px) {
    .course-overlay { display: none; }
    .school-card .school-action { opacity: 1; transform: none; }
    .stat-item:hover { transform: translateY(-4px) scale(1.01); }
}

/* ================================================================
   ===== 全局 UI 增强：现代培训平台风格 =====
   ================================================================ */

/* 管理后台侧边栏增强 */
.admin-sidebar {
    background: linear-gradient(180deg, #0F172A 0%, #1E293B 50%, #0F172A 100%);
    border-right: 1px solid rgba(255,255,255,0.05);
}
.admin-sidebar .logo {
    padding: 28px 20px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.admin-sidebar .logo a {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 700;
    color: white;
    text-decoration: none;
}
.admin-sidebar .logo a::before {
    content: "📚";
    font-size: 28px;
}
.admin-menu li a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 24px;
    color: #94A3B8;
    font-size: 14px;
    font-weight: 500;
    border-left: 3px solid transparent;
    transition: all 0.3s ease;
}
.admin-menu li a:hover {
    background: rgba(255,255,255,0.05);
    color: white;
    border-left-color: #4F46E5;
}
.admin-menu li a.active {
    background: linear-gradient(90deg, rgba(79,70,229,0.15), transparent);
    color: white;
    border-left-color: #4F46E5;
}
.admin-menu li a i {
    width: 20px;
    text-align: center;
    font-size: 16px;
}

/* 管理后台内容区增强 */
.admin-content {
    background: linear-gradient(135deg, #F8FAFC 0%, #F1F5F9 100%);
    min-height: 100vh;
}
.admin-header {
    background: white;
    border-bottom: 1px solid #E2E8F0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}

/* 统计卡片增强 */
.stat-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}
.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    opacity: 0;
    transition: opacity 0.3s ease;
}
.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}
.stat-card:hover::before {
    opacity: 1;
}
.stat-card .stat-icon {
    font-size: 40px;
    margin-bottom: 16px;
    opacity: 0.9;
}
.stat-card .stat-value {
    font-size: 36px;
    font-weight: 800;
    background: linear-gradient(135deg, #1F2937, #374151);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-card .stat-title {
    color: #6B7280;
    font-size: 14px;
    font-weight: 500;
    margin-top: 8px;
}

/* 表格容器增强 */
.table-container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    overflow: hidden;
}
.table-container h3 {
    padding: 20px 24px;
    margin: 0;
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
    border-bottom: 2px solid #F1F5F9;
    display: flex;
    align-items: center;
    gap: 10px;
}
.table-container h3 i {
    color: var(--primary);
}

/* 表格增强 */
.table {
    width: 100%;
    border-collapse: collapse;
}
.table th {
    padding: 14px 16px;
    font-size: 12px;
    font-weight: 600;
    color: #64748B;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: #F8FAFC;
    border-bottom: 2px solid #E2E8F0;
}
.table td {
    padding: 14px 16px;
    font-size: 14px;
    color: #334155;
    border-bottom: 1px solid #F1F5F9;
}
.table tbody tr {
    transition: background 0.2s ease;
}
.table tbody tr:hover {
    background: #F8FAFC;
}
.table tbody tr:last-child td {
    border-bottom: none;
}

/* 按钮增强 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 600;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}
.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.btn-primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.btn-success {
    background: linear-gradient(135deg, #10B981, #059669);
    color: white;
}
.btn-danger {
    background: linear-gradient(135deg, #EF4444, #DC2626);
    color: white;
}
.btn-warning {
    background: linear-gradient(135deg, #F59E0B, #D97706);
    color: white;
}
.btn-info {
    background: linear-gradient(135deg, #06B6D4, #0891B2);
    color: white;
}
.btn-default {
    background: #F1F5F9;
    color: #475569;
    border: 1px solid #E2E8F0;
}
.btn-default:hover {
    background: #E2E8F0;
}
.btn-xs {
    padding: 6px 12px;
    font-size: 12px;
    border-radius: 8px;
}
.btn-block {
    display: flex;
    width: 100%;
}

/* 标签增强 */
.label {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
}
.label-success {
    background: rgba(16,185,129,0.1);
    color: #059669;
}
.label-danger {
    background: rgba(239,68,68,0.1);
    color: #DC2626;
}
.label-warning {
    background: rgba(245,158,11,0.1);
    color: #D97706;
}
.label-info {
    background: rgba(6,182,212,0.1);
    color: #0891B2;
}
.label-default {
    background: #F1F5F9;
    color: #64748B;
}

/* 表单控件增强 */
.form-control {
    display: block;
    width: 100%;
    padding: 12px 16px;
    font-size: 14px;
    line-height: 1.5;
    color: #334155;
    background: white;
    border: 2px solid #E2E8F0;
    border-radius: 10px;
    transition: all 0.3s ease;
}
.form-control:focus {
    border-color: #4F46E5;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
    outline: none;
}
.form-control::placeholder {
    color: #94A3B8;
}

/* 登录页面增强 */
.login-section {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1E3A5F 0%, #0D2137 50%, #1A365D 100%);
    position: relative;
    overflow: hidden;
}
.login-section::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.03)" stroke-width="0.5"/></svg>') repeat;
    background-size: 80px;
}
.login-card {
    background: white;
    border-radius: 20px;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
    overflow: hidden;
    width: 420px;
    max-width: 90%;
    position: relative;
    z-index: 1;
}
.login-card-header {
    padding: 40px 40px 30px;
    text-align: center;
    background: linear-gradient(135deg, #4F46E5 0%, #7C3AED 100%);
    color: white;
}
.login-card-header .icon {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    border-radius: 50%;
    background: rgba(255,255,255,0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
}
.login-card-header h2 {
    margin: 0;
    font-size: 24px;
    font-weight: 700;
}
.login-card-header p {
    margin: 10px 0 0;
    opacity: 0.9;
    font-size: 14px;
}
.login-card-body {
    padding: 40px;
}

/* 响应式优化 */
@media (max-width: 768px) {
    .admin-sidebar {
        width: 70px;
    }
    .admin-sidebar .logo a {
        font-size: 0;
    }
    .admin-sidebar .logo a::before {
        font-size: 24px;
    }
    .admin-content {
        margin-left: 70px;
    }
    .admin-menu li a span {
        display: none;
    }
    .stat-card {
        padding: 16px;
    }
    .stat-card .stat-value {
        font-size: 28px;
    }
    .table-container {
        margin-bottom: 20px;
    }
}

/* ================================================================
   ===== 考试页面 UI 增强 =====
   ================================================================ */

/* 考试面板 */
.panel {
    background: white;
    border-radius: 16px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    overflow: hidden;
    margin-bottom: 24px;
}
.panel-heading {
    padding: 18px 24px;
    background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
    border-bottom: 2px solid #E2E8F0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.panel-heading h3,
.panel-heading .panel-title {
    margin: 0;
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
    display: flex;
    align-items: center;
    gap: 10px;
}
.panel-heading h3 i,
.panel-heading .panel-title i {
    color: #4F46E5;
}
.panel-body {
    padding: 24px;
}

/* 考试信息卡片 */
.exam-info-card {
    background: linear-gradient(135deg, #EEF2FF, #E0E7FF);
    border-radius: 12px;
    padding: 20px;
    display: flex;
    flex-wrap: wrap;
    gap: 20px;
    margin-bottom: 20px;
}
.exam-info-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #374151;
}
.exam-info-item i {
    color: #4F46E5;
    font-size: 16px;
}

/* 选项样式 */
.radio label,
.checkbox label {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    margin: 0;
    border-radius: 10px;
    border: 2px solid #E5E7EB;
    transition: all 0.3s ease;
    cursor: pointer;
}
.radio label:hover,
.checkbox label:hover {
    background: #F8FAFC;
    border-color: #C7D2FE;
}
.radio input:checked + *,
.checkbox input:checked + * {
    color: #4F46E5;
    font-weight: 600;
}
.radio:has(input:checked) label,
.checkbox:has(input:checked) label {
    background: #EEF2FF;
    border-color: #4F46E5;
}

/* 提交按钮区域 */
.exam-submit-area {
    text-align: center;
    padding: 40px 0;
    background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
    border-radius: 16px;
    margin-top: 30px;
}
.exam-submit-area .btn {
    padding: 14px 40px;
    font-size: 16px;
    border-radius: 12px;
    margin: 0 10px;
}

/* 考试结果页面 */
.exam-result-header {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    padding: 40px;
    border-radius: 16px;
    text-align: center;
    margin-bottom: 30px;
}
.exam-result-header .score {
    font-size: 64px;
    font-weight: 800;
    margin: 20px 0;
}
.exam-result-header .status {
    font-size: 18px;
    opacity: 0.9;
}

/* 题目卡片 */
.question-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    border-left: 4px solid #4F46E5;
}
.question-card.correct {
    border-left-color: #10B981;
}
.question-card.incorrect {
    border-left-color: #EF4444;
}
.question-card .question-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}
.question-card .question-type {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    background: #EEF2FF;
    color: #4F46E5;
}
.question-card .question-score {
    font-weight: 700;
    color: #EF4444;
}

/* ================================================================
   ===== 学员中心 UI 增强 =====
   ================================================================ */

/* 用户信息卡片 */
.user-profile-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.user-profile-header {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    padding: 40px 30px 30px;
    text-align: center;
    color: white;
}
.user-avatar {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    background: rgba(255,255,255,0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    font-weight: 700;
    margin: 0 auto 16px;
    border: 4px solid rgba(255,255,255,0.3);
    transition: transform 0.3s ease;
}
.user-avatar:hover {
    transform: scale(1.05);
}

/* 侧边导航 */
.user-nav {
    list-style: none;
    padding: 16px 0;
    margin: 0;
}
.user-nav li a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 24px;
    color: #4B5563;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
}
.user-nav li a:hover {
    background: #F8FAFC;
    color: #4F46E5;
}
.user-nav li a.active {
    background: #EEF2FF;
    color: #4F46E5;
    font-weight: 600;
    border-left-color: #4F46E5;
}
.user-nav li a i {
    width: 20px;
    text-align: center;
    font-size: 16px;
}
.user-nav li:last-child a {
    border-top: 1px solid #F3F4F6;
    margin-top: 8px;
    padding-top: 20px;
}
.user-nav li:last-child a:hover {
    color: #EF4444;
    background: #FEF2F2;
}

/* 统计卡片组 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
    margin-bottom: 24px;
}
.stat-mini-card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    transition: all 0.3s ease;
}
.stat-mini-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}
.stat-mini-card .icon {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    flex-shrink: 0;
}
.stat-mini-card .icon.blue { background: #EEF2FF; color: #4F46E5; }
.stat-mini-card .icon.green { background: #F0FDF4; color: #10B981; }
.stat-mini-card .icon.orange { background: #FFF7ED; color: #F59E0B; }
.stat-mini-card .icon.pink { background: #FDF2F8; color: #EC4899; }
.stat-mini-card .value {
    font-size: 28px;
    font-weight: 800;
    color: #1F2937;
    line-height: 1;
}
.stat-mini-card .label {
    font-size: 13px;
    color: #6B7280;
    margin-top: 4px;
}

/* 课程表格 */
.course-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
}
.course-table th {
    padding: 14px 16px;
    font-size: 12px;
    font-weight: 600;
    color: #64748B;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: #F8FAFC;
    border-bottom: 2px solid #E2E8F0;
}
.course-table td {
    padding: 16px;
    font-size: 14px;
    color: #334155;
    border-bottom: 1px solid #F1F5F9;
    vertical-align: middle;
}
.course-table tbody tr {
    transition: all 0.2s ease;
}
.course-table tbody tr:hover {
    background: #F8FAFC;
}

/* ================================================================
   ===== 响应式优化 =====
   ================================================================ */

@media (max-width: 992px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 576px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    .stat-mini-card {
        padding: 16px;
    }
    .stat-mini-card .value {
        font-size: 24px;
    }
    .exam-info-card {
        flex-direction: column;
        gap: 12px;
    }
}

/* ================================================================
   ===== 全局 UI 增强：表单、侧边栏、空状态 =====
   ================================================================ */

/* 表单页面增强 */
.form-card {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.form-card h3 {
    margin: 0 0 24px;
    font-size: 20px;
    font-weight: 700;
    color: #1F2937;
    display: flex;
    align-items: center;
    gap: 10px;
    padding-bottom: 16px;
    border-bottom: 2px solid #F1F5F9;
}
.form-card h3 i {
    color: #4F46E5;
}

/* 表单组增强 */
.form-group {
    margin-bottom: 20px;
}
.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 600;
    color: #374151;
}
.form-group label .required {
    color: #EF4444;
    margin-left: 2px;
}
.form-group .help-block {
    font-size: 12px;
    color: #9CA3AF;
    margin-top: 6px;
}

/* 输入框增强 */
.form-control {
    width: 100%;
    padding: 12px 16px;
    font-size: 14px;
    border: 2px solid #E5E7EB;
    border-radius: 10px;
    transition: all 0.3s ease;
    background: #FAFBFC;
}
.form-control:focus {
    border-color: #4F46E5;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
    background: white;
    outline: none;
}
.form-control::placeholder {
    color: #9CA3AF;
}
.form-control:disabled {
    background: #F3F4F6;
    color: #6B7280;
    cursor: not-allowed;
}

/* 文件上传增强 */
input[type="file"].form-control {
    padding: 10px;
    border-style: dashed;
    border-width: 2px;
    background: #FAFBFC;
}
input[type="file"].form-control:hover {
    border-color: #4F46E5;
    background: #F5F3FF;
}

/* 侧边导航增强 */
.side-nav {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.side-nav-header {
    text-align: center;
    padding: 30px 20px 20px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.side-nav-header .avatar {
    width: 90px;
    height: 90px;
    border-radius: 50%;
    background: rgba(255,255,255,0.2);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 36px;
    font-weight: 700;
    margin: 0 auto 16px;
    border: 4px solid rgba(255,255,255,0.3);
}
.side-nav-header h4 {
    margin: 0;
    font-size: 18px;
    font-weight: 700;
}
.side-nav-header p {
    margin: 6px 0 0;
    opacity: 0.8;
    font-size: 13px;
}
.side-nav-menu {
    list-style: none;
    padding: 16px 0;
    margin: 0;
}
.side-nav-menu li a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 24px;
    color: #4B5563;
    font-size: 14px;
    font-weight: 500;
    transition: all 0.3s ease;
    border-left: 3px solid transparent;
}
.side-nav-menu li a:hover {
    background: #F8FAFC;
    color: #4F46E5;
    padding-left: 28px;
}
.side-nav-menu li a.active {
    background: #EEF2FF;
    color: #4F46E5;
    font-weight: 600;
    border-left-color: #4F46E5;
}
.side-nav-menu li a i {
    width: 20px;
    text-align: center;
    font-size: 16px;
}
.side-nav-menu li:last-child a {
    border-top: 1px solid #F3F4F6;
    margin-top: 8px;
    padding-top: 20px;
}
.side-nav-menu li:last-child a:hover {
    color: #EF4444;
    background: #FEF2F2;
}

/* 内容卡片增强 */
.content-card {
    background: white;
    border-radius: 16px;
    padding: 30px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.content-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
    padding-bottom: 16px;
    border-bottom: 2px solid #F1F5F9;
}
.content-card-header h3 {
    margin: 0;
    font-size: 18px;
    font-weight: 700;
    color: #1F2937;
    display: flex;
    align-items: center;
    gap: 10px;
}
.content-card-header h3 i {
    color: #4F46E5;
}

/* 空状态增强 */
.empty-state {
    text-align: center;
    padding: 60px 20px;
    color: #9CA3AF;
}
.empty-state .icon {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: #F3F4F6;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
    font-size: 40px;
    color: #D1D5DB;
}
.empty-state h4 {
    font-size: 18px;
    font-weight: 600;
    color: #6B7280;
    margin-bottom: 10px;
}
.empty-state p {
    font-size: 14px;
    margin-bottom: 20px;
}

/* 积分卡片增强 */
.points-card {
    background: linear-gradient(135deg, #FEF3C7, #FDE68A);
    border-radius: 16px;
    padding: 30px;
    text-align: center;
    box-shadow: 0 4px 15px rgba(245,158,11,0.2);
}
.points-card .points-value {
    font-size: 48px;
    font-weight: 800;
    color: #92400E;
    margin: 10px 0;
}
.points-card .points-label {
    font-size: 14px;
    color: #B45309;
}

/* 积分表格增强 */
.points-table {
    width: 100%;
    border-collapse: separate;
    border-spacing: 0;
}
.points-table th {
    padding: 14px 16px;
    font-size: 12px;
    font-weight: 600;
    color: #64748B;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: #F8FAFC;
    border-bottom: 2px solid #E2E8F0;
}
.points-table td {
    padding: 14px 16px;
    font-size: 14px;
    color: #334155;
    border-bottom: 1px solid #F1F5F9;
}
.points-table tbody tr {
    transition: background 0.2s ease;
}
.points-table tbody tr:hover {
    background: #FFFBEB;
}

/* 积分徽章 */
.points-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 700;
    background: linear-gradient(135deg, #F59E0B, #D97706);
    color: white;
    box-shadow: 0 2px 8px rgba(245,158,11,0.3);
}

/* 通知卡片增强 */
.notification-card {
    background: white;
    border-radius: 12px;
    padding: 16px 20px;
    margin-bottom: 12px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.04);
    border-left: 4px solid transparent;
    transition: all 0.3s ease;
}
.notification-card:hover {
    transform: translateX(4px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.notification-card.unread {
    border-left-color: #4F46E5;
    background: #FAFBFF;
}
.notification-card .notification-title {
    font-weight: 600;
    color: #1F2937;
    margin-bottom: 6px;
}
.notification-card .notification-content {
    font-size: 13px;
    color: #6B7280;
    line-height: 1.5;
}
.notification-card .notification-time {
    font-size: 12px;
    color: #9CA3AF;
    margin-top: 8px;
}

/* 反馈卡片增强 */
.feedback-card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 16px;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
}
.feedback-card:hover {
    box-shadow: 0 4px 16px rgba(0,0,0,0.08);
}
.feedback-card .feedback-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 12px;
}
.feedback-card .feedback-title {
    font-weight: 600;
    color: #1F2937;
    font-size: 15px;
}
.feedback-card .feedback-content {
    font-size: 14px;
    color: #4B5563;
    line-height: 1.6;
    margin-bottom: 12px;
}
.feedback-card .feedback-reply {
    background: #F8FAFC;
    border-radius: 8px;
    padding: 12px 16px;
    border-left: 3px solid #4F46E5;
}
.feedback-card .feedback-reply .reply-label {
    font-size: 12px;
    font-weight: 600;
    color: #4F46E5;
    margin-bottom: 6px;
}

/* 学习记录卡片增强 */
.learning-record-card {
    background: white;
    border-radius: 12px;
    padding: 16px 20px;
    margin-bottom: 12px;
    box-shadow: 0 1px 4px rgba(0,0,0,0.04);
    display: flex;
    align-items: center;
    gap: 16px;
    transition: all 0.3s ease;
}
.learning-record-card:hover {
    transform: translateX(4px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.08);
}
.learning-record-card .record-icon {
    width: 48px;
    height: 48px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 20px;
    flex-shrink: 0;
}
.learning-record-card .record-icon.blue {
    background: #EEF2FF;
    color: #4F46E5;
}
.learning-record-card .record-icon.green {
    background: #F0FDF4;
    color: #10B981;
}
.learning-record-card .record-info {
    flex: 1;
}
.learning-record-card .record-title {
    font-weight: 600;
    color: #1F2937;
    margin-bottom: 4px;
}
.learning-record-card .record-meta {
    font-size: 13px;
    color: #6B7280;
}

/* 按钮组增强 */
.btn-group-v2 {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}
.btn-group-v2 .btn {
    flex: 1;
    min-width: 120px;
}

/* 响应式优化 */
@media (max-width: 768px) {
    .form-card,
    .content-card {
        padding: 20px;
    }
    .side-nav-header {
        padding: 20px 16px 16px;
    }
    .side-nav-header .avatar {
        width: 70px;
        height: 70px;
        font-size: 28px;
    }
    .points-card {
        padding: 20px;
    }
    .points-card .points-value {
        font-size: 36px;
    }
}

/* ================================================================
   ===== 管理后台 & 学校后台 UI 增强 =====
   ================================================================ */

/* 侧边栏增强 */
.admin-sidebar {
    background: linear-gradient(180deg, #0F172A 0%, #1E293B 50%, #0F172A 100%);
    border-right: 1px solid rgba(255,255,255,0.05);
    box-shadow: 4px 0 20px rgba(0,0,0,0.1);
}
.admin-sidebar .logo {
    padding: 28px 20px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.admin-sidebar .logo a {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 18px;
    font-weight: 700;
    color: white;
    text-decoration: none;
}
.admin-sidebar .logo a::before {
    content: "📚";
    font-size: 28px;
}

/* 侧边栏菜单增强 */
.admin-menu {
    list-style: none;
    padding: 16px 0;
    margin: 0;
}
.admin-menu li a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 24px;
    color: #94A3B8;
    font-size: 14px;
    font-weight: 500;
    border-left: 3px solid transparent;
    transition: all 0.3s ease;
}
.admin-menu li a:hover {
    background: rgba(255,255,255,0.05);
    color: white;
    border-left-color: #4F46E5;
}
.admin-menu li a.active {
    background: linear-gradient(90deg, rgba(79,70,229,0.15), transparent);
    color: white;
    border-left-color: #4F46E5;
}
.admin-menu li a i {
    width: 20px;
    text-align: center;
    font-size: 16px;
}
.admin-menu li.section-title {
    padding: 20px 24px 8px;
    font-size: 11px;
    color: #64748B;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

/* 内容区增强 */
.admin-content {
    background: linear-gradient(135deg, #F8FAFC 0%, #F1F5F9 100%);
    min-height: 100vh;
}

/* 头部增强 */
.admin-header {
    background: white;
    border-bottom: 1px solid #E2E8F0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    padding: 16px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.admin-header h3 {
    margin: 0;
    font-size: 18px;
    font-weight: 700;
    color: #1F2937;
}

/* 统计卡片增强 */
.stat-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}
.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, var(--primary), var(--secondary));
    opacity: 0;
    transition: opacity 0.3s ease;
}
.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}
.stat-card:hover::before {
    opacity: 1;
}
.stat-card .stat-icon {
    font-size: 40px;
    margin-bottom: 16px;
    opacity: 0.9;
}
.stat-card .stat-value {
    font-size: 36px;
    font-weight: 800;
    background: linear-gradient(135deg, #1F2937, #374151);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-card .stat-title {
    color: #6B7280;
    font-size: 14px;
    font-weight: 500;
    margin-top: 8px;
}

/* 表格容器增强 */
.table-container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    overflow: hidden;
}
.table-container h3 {
    padding: 20px 24px;
    margin: 0;
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
    border-bottom: 2px solid #F1F5F9;
    display: flex;
    align-items: center;
    gap: 10px;
}
.table-container h3 i {
    color: var(--primary);
}

/* 表格增强 */
.table {
    width: 100%;
    border-collapse: collapse;
}
.table th {
    padding: 14px 16px;
    font-size: 12px;
    font-weight: 600;
    color: #64748B;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: #F8FAFC;
    border-bottom: 2px solid #E2E8F0;
}
.table td {
    padding: 14px 16px;
    font-size: 14px;
    color: #334155;
    border-bottom: 1px solid #F1F5F9;
}
.table tbody tr {
    transition: background 0.2s ease;
}
.table tbody tr:hover {
    background: #F8FAFC;
}
.table tbody tr:last-child td {
    border-bottom: none;
}

/* 按钮增强 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 600;
    border-radius: 10px;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    text-decoration: none;
}
.btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}
.btn-primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.btn-success {
    background: linear-gradient(135deg, #10B981, #059669);
    color: white;
}
.btn-danger {
    background: linear-gradient(135deg, #EF4444, #DC2626);
    color: white;
}
.btn-warning {
    background: linear-gradient(135deg, #F59E0B, #D97706);
    color: white;
}
.btn-info {
    background: linear-gradient(135deg, #06B6D4, #0891B2);
    color: white;
}
.btn-default {
    background: #F1F5F9;
    color: #475569;
    border: 1px solid #E2E8F0;
}
.btn-default:hover {
    background: #E2E8F0;
}
.btn-xs {
    padding: 6px 12px;
    font-size: 12px;
    border-radius: 8px;
}
.btn-sm {
    padding: 8px 16px;
    font-size: 13px;
}
.btn-block {
    display: flex;
    width: 100%;
}

/* 标签增强 */
.label {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 6px;
    font-size: 12px;
    font-weight: 600;
}
.label-success {
    background: rgba(16,185,129,0.1);
    color: #059669;
}
.label-danger {
    background: rgba(239,68,68,0.1);
    color: #DC2626;
}
.label-warning {
    background: rgba(245,158,11,0.1);
    color: #D97706;
}
.label-info {
    background: rgba(6,182,212,0.1);
    color: #0891B2;
}
.label-default {
    background: #F1F5F9;
    color: #64748B;
}
.label-primary {
    background: rgba(79,70,229,0.1);
    color: #4F46E5;
}

/* 表单控件增强 */
.form-control {
    display: block;
    width: 100%;
    padding: 12px 16px;
    font-size: 14px;
    line-height: 1.5;
    color: #334155;
    background: white;
    border: 2px solid #E2E8F0;
    border-radius: 10px;
    transition: all 0.3s ease;
}
.form-control:focus {
    border-color: #4F46E5;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
    outline: none;
}
.form-control::placeholder {
    color: #94A3B8;
}
.form-control:disabled {
    background: #F3F4F6;
    color: #6B7280;
    cursor: not-allowed;
}

/* 表单组增强 */
.form-group {
    margin-bottom: 20px;
}
.form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 600;
    color: #374151;
}
.form-group .help-block {
    font-size: 12px;
    color: #9CA3AF;
    margin-top: 6px;
}

/* 警告框增强 */
.alert {
    border-radius: 12px;
    border: none;
    padding: 16px 20px;
    display: flex;
    align-items: center;
    gap: 12px;
    margin-bottom: 20px;
}
.alert i {
    font-size: 20px;
}
.alert-success {
    background: rgba(16,185,129,0.1);
    color: #065F46;
    border-left: 4px solid #10B981;
}
.alert-danger {
    background: rgba(239,68,68,0.1);
    color: #991B1B;
    border-left: 4px solid #EF4444;
}
.alert-warning {
    background: rgba(245,158,11,0.1);
    color: #92400E;
    border-left: 4px solid #F59E0B;
}
.alert-info {
    background: rgba(6,182,212,0.1);
    color: #155E75;
    border-left: 4px solid #06B6D4;
}

/* 面板增强 */
.panel {
    background: white;
    border-radius: 16px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    overflow: hidden;
    margin-bottom: 24px;
}
.panel-heading {
    padding: 18px 24px;
    background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
    border-bottom: 2px solid #E2E8F0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.panel-heading h3,
.panel-heading .panel-title {
    margin: 0;
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
    display: flex;
    align-items: center;
    gap: 10px;
}
.panel-body {
    padding: 24px;
}

/* 分页增强 */
.pagination {
    display: flex;
    justify-content: center;
    gap: 8px;
    margin-top: 24px;
}
.pagination > li > a,
.pagination > li > span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 40px;
    height: 40px;
    padding: 8px 12px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.3s ease;
    border: 1px solid #E5E7EB;
    color: #4B5563;
    background: white;
}
.pagination > li > a:hover {
    background: #4F46E5;
    color: white;
    border-color: #4F46E5;
    transform: translateY(-2px);
}
.pagination > .active > a,
.pagination > .active > span {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border-color: transparent;
    box-shadow: 0 4px 12px rgba(79,70,229,0.3);
}

/* 进度条增强 */
.progress {
    height: 10px;
    border-radius: 10px;
    background: #E5E7EB;
    overflow: hidden;
}
.progress-bar {
    background: linear-gradient(90deg, #4F46E5, #7C3AED);
    border-radius: 10px;
    transition: width 0.5s ease;
}

/* 模态框增强 */
.modal-content {
    border-radius: 16px;
    border: none;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
}
.modal-header {
    border-bottom: 1px solid #E5E7EB;
    padding: 20px 24px;
}
.modal-header .modal-title {
    font-size: 18px;
    font-weight: 700;
}
.modal-body {
    padding: 24px;
}
.modal-footer {
    border-top: 1px solid #E5E7EB;
    padding: 16px 24px;
}

/* 响应式优化 */
@media (max-width: 992px) {
    .admin-sidebar {
        width: 80px;
    }
    .admin-sidebar .logo a {
        font-size: 0;
    }
    .admin-sidebar .logo a::before {
        font-size: 24px;
    }
    .admin-content {
        margin-left: 80px;
    }
    .admin-menu li a span {
        display: none;
    }
    .admin-menu li.section-title {
        display: none;
    }
}
@media (max-width: 768px) {
    .admin-sidebar {
        width: 60px;
    }
    .admin-sidebar .logo a {
        font-size: 0;
    }
    .admin-sidebar .logo a::before {
        font-size: 22px;
    }
    .admin-content {
        margin-left: 60px;
    }
    .admin-header {
        padding: 12px 16px;
    }
    .admin-header h3 {
        font-size: 16px;
    }
    .stat-card {
        padding: 16px;
    }
    .stat-card .stat-value {
        font-size: 28px;
    }
    .table-container {
        margin-bottom: 20px;
    }
}

/* ================================================================
   ===== 搜索面板 & 筛选器 UI 增强 =====
   ================================================================ */

/* 搜索面板 */
.search-panel {
    background: #F8FAFC;
    border-radius: 12px;
    padding: 20px;
    margin-bottom: 20px;
    border: 1px solid #E2E8F0;
}
.search-panel .form-inline {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    align-items: center;
}
.search-panel .form-group {
    margin-bottom: 0;
    flex: 1;
    min-width: 150px;
}
.search-panel .form-control {
    width: 100%;
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 13px;
}
.search-panel .btn {
    white-space: nowrap;
}

/* 高级搜索面板 */
.advanced-search-panel {
    background: white;
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 20px;
    border: 1px solid #E2E8F0;
    box-shadow: 0 2px 8px rgba(0,0,0,0.04);
}
.filter-row {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
    gap: 16px;
    margin-bottom: 16px;
}
.filter-row .form-group {
    margin-bottom: 0;
}
.filter-row .form-group label {
    display: block;
    font-size: 12px;
    font-weight: 600;
    color: #64748B;
    margin-bottom: 6px;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.filter-row .form-control {
    border-radius: 8px;
    padding: 10px 14px;
    font-size: 13px;
    border: 1px solid #E2E8F0;
    transition: all 0.3s ease;
}
.filter-row .form-control:focus {
    border-color: #4F46E5;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
}

/* 高级搜索切换按钮 */
.advanced-search-toggle {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border-radius: 8px;
    background: #EEF2FF;
    color: #4F46E5;
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
    border: none;
}
.advanced-search-toggle:hover {
    background: #E0E7FF;
    transform: translateY(-1px);
}

/* 工具栏 */
.toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    flex-wrap: wrap;
    gap: 12px;
}
.toolbar-left {
    display: flex;
    align-items: center;
    gap: 12px;
}
.toolbar-right {
    display: flex;
    align-items: center;
    gap: 10px;
    flex-wrap: wrap;
}

/* 表格操作列 */
.table-actions {
    display: flex;
    gap: 6px;
    align-items: center;
}
.table-actions .btn {
    padding: 6px 10px;
    font-size: 12px;
    border-radius: 6px;
}

/* 表格状态列 */
.table-status {
    display: inline-flex;
    align-items: center;
    gap: 4px;
}
.table-status .dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
}
.table-status .dot.green { background: #10B981; }
.table-status .dot.red { background: #EF4444; }
.table-status .dot.yellow { background: #F59E0B; }
.table-status .dot.gray { background: #9CA3AF; }

/* 批量操作栏 */
.batch-actions {
    display: flex;
    align-items: center;
    gap: 10px;
    padding: 12px 16px;
    background: #EEF2FF;
    border-radius: 8px;
    margin-bottom: 16px;
}
.batch-actions .batch-count {
    font-size: 13px;
    color: #4F46E5;
    font-weight: 600;
}

/* 分页信息 */
.pagination-info {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-top: 20px;
    padding-top: 16px;
    border-top: 1px solid #F1F5F9;
    font-size: 13px;
    color: #64748B;
}

/* 空数据表格 */
.table-empty {
    text-align: center;
    padding: 60px 20px;
    color: #9CA3AF;
}
.table-empty i {
    font-size: 48px;
    margin-bottom: 16px;
    display: block;
    color: #D1D5DB;
}
.table-empty p {
    font-size: 15px;
    margin-bottom: 8px;
}

/* 操作按钮组 */
.action-buttons {
    display: flex;
    gap: 8px;
    flex-wrap: wrap;
}
.action-buttons .btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
}

/* 表格 hover 效果增强 */
.table tbody tr {
    transition: all 0.2s ease;
}
.table tbody tr:hover {
    background: linear-gradient(90deg, #F8FAFC, #F1F5F9);
    transform: translateX(2px);
}

/* 评分星星 */
.rating-stars {
    display: inline-flex;
    gap: 2px;
    color: #F59E0B;
}
.rating-stars i {
    font-size: 14px;
}
.rating-stars i.empty {
    color: #D1D5DB;
}

/* 状态徽章 */
.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}
.status-badge.active {
    background: rgba(16,185,129,0.1);
    color: #059669;
}
.status-badge.inactive {
    background: rgba(239,68,68,0.1);
    color: #DC2626;
}
.status-badge.pending {
    background: rgba(245,158,11,0.1);
    color: #D97706;
}

/* 响应式优化 */
@media (max-width: 768px) {
    .search-panel {
        padding: 16px;
    }
    .filter-row {
        grid-template-columns: 1fr;
    }
    .toolbar {
        flex-direction: column;
        align-items: stretch;
    }
    .toolbar-left,
    .toolbar-right {
        justify-content: center;
    }
    .batch-actions {
        flex-direction: column;
        text-align: center;
    }
    .pagination-info {
        flex-direction: column;
        gap: 12px;
        text-align: center;
    }
}

/* ================================================================
   ===== 数据看板 & 统计卡片 UI 增强 =====
   ================================================================ */

/* 数据看板容器 */
.dashboard-container {
    padding: 24px;
}

/* 统计卡片网格 */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
    margin-bottom: 24px;
}

/* 数据统计卡片 */
.data-stat-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}
.data-stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    opacity: 0;
    transition: opacity 0.3s ease;
}
.data-stat-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.12);
}
.data-stat-card:hover::before {
    opacity: 1;
}
.data-stat-card .icon {
    width: 64px;
    height: 64px;
    margin: 0 auto 16px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 28px;
    transition: transform 0.4s ease;
}
.data-stat-card:hover .icon {
    transform: scale(1.1) rotate(5deg);
}
.data-stat-card .icon.blue {
    background: linear-gradient(135deg, rgba(79,70,229,0.12), rgba(79,70,229,0.05));
    color: #4F46E5;
}
.data-stat-card .icon.green {
    background: linear-gradient(135deg, rgba(16,185,129,0.12), rgba(16,185,129,0.05));
    color: #10B981;
}
.data-stat-card .icon.orange {
    background: linear-gradient(135deg, rgba(245,158,11,0.12), rgba(245,158,11,0.05));
    color: #F59E0B;
}
.data-stat-card .icon.red {
    background: linear-gradient(135deg, rgba(239,68,68,0.12), rgba(239,68,68,0.05));
    color: #EF4444;
}
.data-stat-card .icon.purple {
    background: linear-gradient(135deg, rgba(139,92,246,0.12), rgba(139,92,246,0.05));
    color: #8B5CF6;
}
.data-stat-card .icon.cyan {
    background: linear-gradient(135deg, rgba(6,182,212,0.12), rgba(6,182,212,0.05));
    color: #06B6D4;
}
.data-stat-card .icon.pink {
    background: linear-gradient(135deg, rgba(236,72,153,0.12), rgba(236,72,153,0.05));
    color: #EC4899;
}
.data-stat-card .icon.teal {
    background: linear-gradient(135deg, rgba(20,184,166,0.12), rgba(20,184,166,0.05));
    color: #14B8A6;
}
.data-stat-card .value {
    font-size: 36px;
    font-weight: 800;
    color: #1F2937;
    margin-bottom: 8px;
    background: linear-gradient(135deg, #1F2937, #374151);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.data-stat-card .label {
    font-size: 14px;
    color: #6B7280;
    font-weight: 500;
}

/* 数据卡片装饰线 */
.data-stat-card.blue::before { background: linear-gradient(90deg, #4F46E5, #7C3AED); }
.data-stat-card.green::before { background: linear-gradient(90deg, #10B981, #34D399); }
.data-stat-card.orange::before { background: linear-gradient(90deg, #F59E0B, #FBBF24); }
.data-stat-card.red::before { background: linear-gradient(90deg, #EF4444, #F87171); }
.data-stat-card.purple::before { background: linear-gradient(90deg, #8B5CF6, #A78BFA); }
.data-stat-card.cyan::before { background: linear-gradient(90deg, #06B6D4, #22D3EE); }
.data-stat-card.pink::before { background: linear-gradient(90deg, #EC4899, #F472B6); }
.data-stat-card.teal::before { background: linear-gradient(90deg, #14B8A6, #2DD4BF); }

/* 数据分布卡片 */
.data-distribution-card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
    overflow: hidden;
}
.data-distribution-card .card-header {
    padding: 20px 24px;
    background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
    border-bottom: 2px solid #E2E8F0;
    display: flex;
    align-items: center;
    gap: 10px;
}
.data-distribution-card .card-header i {
    color: #4F46E5;
    font-size: 18px;
}
.data-distribution-card .card-header h4 {
    margin: 0;
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
}
.data-distribution-card .card-body {
    padding: 24px;
}

/* 数据分布项 */
.distribution-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 0;
    border-bottom: 1px solid #F1F5F9;
}
.distribution-item:last-child {
    border-bottom: none;
}
.distribution-item .item-label {
    display: flex;
    align-items: center;
    gap: 10px;
    font-size: 14px;
    color: #4B5563;
}
.distribution-item .item-dot {
    width: 10px;
    height: 10px;
    border-radius: 50%;
}
.distribution-item .item-value {
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
}

/* 进度条统计 */
.progress-stat {
    margin-bottom: 16px;
}
.progress-stat .stat-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
}
.progress-stat .stat-label {
    font-size: 13px;
    color: #6B7280;
}
.progress-stat .stat-value {
    font-size: 13px;
    font-weight: 600;
    color: #1F2937;
}
.progress-stat .progress-bar {
    height: 8px;
    border-radius: 10px;
    background: #E5E7EB;
    overflow: hidden;
}
.progress-stat .progress-fill {
    height: 100%;
    border-radius: 10px;
    transition: width 0.5s ease;
}

/* 数据卡片网格（2列） */
.data-grid-2 {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

/* 数据卡片网格（3列） */
.data-grid-3 {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 20px;
}

/* 数据卡片网格（4列） */
.data-grid-4 {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 20px;
}

/* 图标颜色类 */
.text-blue { color: #4F46E5; }
.text-green { color: #10B981; }
.text-orange { color: #F59E0B; }
.text-red { color: #EF4444; }
.text-purple { color: #8B5CF6; }
.text-cyan { color: #06B6D4; }
.text-pink { color: #EC4899; }
.text-teal { color: #14B8A6; }
.text-gray { color: #6B7280; }

/* 背景色类 */
.bg-blue { background: rgba(79,70,229,0.1); }
.bg-green { background: rgba(16,185,129,0.1); }
.bg-orange { background: rgba(245,158,11,0.1); }
.bg-red { background: rgba(239,68,68,0.1); }
.bg-purple { background: rgba(139,92,246,0.1); }
.bg-cyan { background: rgba(6,182,212,0.1); }
.bg-pink { background: rgba(236,72,153,0.1); }
.bg-teal { background: rgba(20,184,166,0.1); }

/* 响应式优化 */
@media (max-width: 992px) {
    .stats-grid {
        grid-template-columns: repeat(2, 1fr);
    }
    .data-grid-2,
    .data-grid-3,
    .data-grid-4 {
        grid-template-columns: 1fr;
    }
}
@media (max-width: 576px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    .data-stat-card {
        padding: 20px;
    }
    .data-stat-card .value {
        font-size: 28px;
    }
}

/* ================================================================
   ===== 学校后台 & 学员详情 UI 增强 =====
   ================================================================ */

/* 学员卡片 */
.student-progress-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    margin-bottom: 20px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
}
.student-progress-card:hover {
    box-shadow: 0 4px 20px rgba(0,0,0,0.08);
}
.student-progress-card .card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 16px;
}
.student-progress-card .student-info {
    display: flex;
    align-items: center;
    gap: 12px;
}
.student-progress-card .student-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 18px;
    font-weight: 700;
}
.student-progress-card .student-name {
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
}
.student-progress-card .student-meta {
    font-size: 13px;
    color: #6B7280;
    margin-top: 4px;
}
.student-progress-card .progress-stats {
    display: flex;
    gap: 20px;
    flex-wrap: wrap;
}
.student-progress-card .progress-stat {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 13px;
    color: #6B7280;
}
.student-progress-card .progress-stat strong {
    color: #1F2937;
    font-weight: 700;
}

/* 进度条增强 */
.progress-bar-container {
    height: 10px;
    background: #E5E7EB;
    border-radius: 10px;
    overflow: hidden;
    margin: 12px 0;
}
.progress-bar-fill {
    height: 100%;
    border-radius: 10px;
    transition: width 0.5s ease;
}
.progress-bar-fill.low {
    background: linear-gradient(90deg, #EF4444, #F87171);
}
.progress-bar-fill.medium {
    background: linear-gradient(90deg, #F59E0B, #FBBF24);
}
.progress-bar-fill.high {
    background: linear-gradient(90deg, #10B981, #34D399);
}

/* 课程行 */
.course-progress-row {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 14px 16px;
    background: #F8FAFC;
    border-radius: 10px;
    margin-bottom: 10px;
    transition: all 0.2s ease;
}
.course-progress-row:hover {
    background: #F1F5F9;
    transform: translateX(4px);
}
.course-progress-row .course-info {
    flex: 1;
}
.course-progress-row .course-title {
    font-weight: 600;
    color: #1F2937;
    margin-bottom: 4px;
}
.course-progress-row .course-meta {
    font-size: 12px;
    color: #6B7280;
}
.course-progress-row .course-actions {
    display: flex;
    gap: 8px;
    align-items: center;
}

/* 状态徽章 */
.status-badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}
.status-badge.blue {
    background: #EEF2FF;
    color: #4F46E5;
}
.status-badge.green {
    background: #F0FDF4;
    color: #10B981;
}
.status-badge.orange {
    background: #FFF7ED;
    color: #F59E0B;
}
.status-badge.red {
    background: #FEF2F2;
    color: #EF4444;
}

/* 学员详情统计卡片 */
.detail-stat-card {
    background: white;
    border-radius: 12px;
    padding: 16px;
    text-align: center;
    box-shadow: 0 1px 4px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
}
.detail-stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}
.detail-stat-card .stat-value {
    font-size: 28px;
    font-weight: 800;
    color: #1F2937;
    background: linear-gradient(135deg, #1F2937, #374151);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.detail-stat-card .stat-label {
    font-size: 12px;
    color: #6B7280;
    margin-top: 4px;
}

/* 详情区块标题 */
.detail-section-title {
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
    padding-bottom: 12px;
    margin-bottom: 16px;
    margin-top: 28px;
    border-bottom: 2px solid #EEF2FF;
    display: flex;
    align-items: center;
    gap: 10px;
}
.detail-section-title i {
    color: #4F46E5;
}

/* 学员信息面板 */
.student-info-panel {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
}
.student-info-panel .info-row {
    display: flex;
    align-items: center;
    padding: 10px 0;
    border-bottom: 1px solid #F1F5F9;
}
.student-info-panel .info-row:last-child {
    border-bottom: none;
}
.student-info-panel .info-label {
    width: 100px;
    font-size: 13px;
    color: #6B7280;
    font-weight: 500;
}
.student-info-panel .info-value {
    flex: 1;
    font-size: 14px;
    color: #1F2937;
}

/* 快捷操作卡片 */
.quick-action-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
}
.quick-action-card .action-grid {
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    gap: 16px;
}
.quick-action-card .action-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 10px;
    padding: 20px;
    border-radius: 12px;
    background: #F8FAFC;
    transition: all 0.3s ease;
    text-decoration: none;
    color: inherit;
}
.quick-action-card .action-item:hover {
    background: #EEF2FF;
    transform: translateY(-4px);
    box-shadow: 0 4px 12px rgba(79,70,229,0.15);
}
.quick-action-card .action-icon {
    width: 50px;
    height: 50px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
}
.quick-action-card .action-icon.blue {
    background: #EEF2FF;
    color: #4F46E5;
}
.quick-action-card .action-icon.green {
    background: #F0FDF4;
    color: #10B981;
}
.quick-action-card .action-icon.orange {
    background: #FFF7ED;
    color: #F59E0B;
}
.quick-action-card .action-label {
    font-size: 14px;
    font-weight: 600;
    color: #1F2937;
}

/* 学校信息卡片 */
.school-info-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
}
.school-info-card .info-item {
    display: flex;
    padding: 12px 0;
    border-bottom: 1px solid #F1F5F9;
}
.school-info-card .info-item:last-child {
    border-bottom: none;
}
.school-info-card .info-label {
    width: 100px;
    font-size: 13px;
    color: #6B7280;
    font-weight: 500;
}
.school-info-card .info-value {
    flex: 1;
    font-size: 14px;
    color: #1F2937;
}

/* 课程列表卡片 */
.course-list-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
    border: 1px solid #F1F5F9;
}
.course-list-card .course-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 14px 0;
    border-bottom: 1px solid #F1F5F9;
}
.course-list-card .course-item:last-child {
    border-bottom: none;
}
.course-list-card .course-title {
    font-weight: 600;
    color: #1F2937;
}
.course-list-card .course-meta {
    font-size: 13px;
    color: #6B7280;
    margin-top: 4px;
}

/* 响应式优化 */
@media (max-width: 992px) {
    .quick-action-card .action-grid {
        grid-template-columns: repeat(2, 1fr);
    }
}
@media (max-width: 576px) {
    .student-progress-card {
        padding: 16px;
    }
    .student-progress-card .progress-stats {
        flex-direction: column;
        gap: 8px;
    }
    .course-progress-row {
        flex-direction: column;
        align-items: flex-start;
        gap: 12px;
    }
    .course-progress-row .course-actions {
        width: 100%;
        justify-content: flex-end;
    }
    .quick-action-card .action-grid {
        grid-template-columns: 1fr;
    }
}

/* ================================================================
   ===== 商业级 UI 增强：加载状态、骨架屏、提示框 =====
   ================================================================ */

/* 加载骨架屏 */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border-radius: 8px;
}
@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}
.skeleton-text {
    height: 14px;
    margin-bottom: 8px;
}
.skeleton-title {
    height: 24px;
    width: 60%;
    margin-bottom: 12px;
}
.skeleton-avatar {
    width: 48px;
    height: 48px;
    border-radius: 50%;
}
.skeleton-card {
    height: 200px;
    border-radius: 16px;
}

/* 加载动画 */
.loading-overlay {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(255,255,255,0.9);
    display: flex;
    align-items: center;
    justify-content: center;
    z-index: 9999;
}
.loading-spinner {
    width: 50px;
    height: 50px;
    border: 4px solid #E5E7EB;
    border-top-color: #4F46E5;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 提示框 Toast */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 10px;
}
.toast {
    background: white;
    border-radius: 12px;
    padding: 16px 20px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.15);
    display: flex;
    align-items: center;
    gap: 12px;
    min-width: 300px;
    max-width: 400px;
    animation: toast-slide-in 0.3s ease;
    border-left: 4px solid transparent;
}
.toast.success {
    border-left-color: #10B981;
}
.toast.error {
    border-left-color: #EF4444;
}
.toast.warning {
    border-left-color: #F59E0B;
}
.toast.info {
    border-left-color: #06B6D4;
}
.toast .toast-icon {
    font-size: 20px;
}
.toast.success .toast-icon { color: #10B981; }
.toast.error .toast-icon { color: #EF4444; }
.toast.warning .toast-icon { color: #F59E0B; }
.toast.info .toast-icon { color: #06B6D4; }
.toast .toast-content {
    flex: 1;
}
.toast .toast-title {
    font-weight: 600;
    color: #1F2937;
    margin-bottom: 2px;
}
.toast .toast-message {
    font-size: 13px;
    color: #6B7280;
}
.toast .toast-close {
    background: none;
    border: none;
    color: #9CA3AF;
    cursor: pointer;
    padding: 4px;
    font-size: 16px;
}
@keyframes toast-slide-in {
    from {
        transform: translateX(100%);
        opacity: 0;
    }
    to {
        transform: translateX(0);
        opacity: 1;
    }
}

/* 下拉菜单增强 */
.dropdown-menu {
    border-radius: 12px;
    border: 1px solid #E5E7EB;
    box-shadow: 0 10px 40px rgba(0,0,0,0.12);
    padding: 8px;
    min-width: 180px;
}
.dropdown-menu > li > a {
    padding: 10px 16px;
    border-radius: 8px;
    font-size: 14px;
    color: #4B5563;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 10px;
}
.dropdown-menu > li > a:hover {
    background: #F3F4F6;
    color: #1F2937;
}
.dropdown-menu > li > a i {
    width: 18px;
    color: #9CA3AF;
}
.dropdown-menu > .divider {
    height: 1px;
    background: #E5E7EB;
    margin: 8px 0;
}

/* 工具提示增强 */
.tooltip-inner {
    background: #1F2937;
    border-radius: 8px;
    padding: 8px 14px;
    font-size: 13px;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
    max-width: 250px;
}

/* 表单验证状态 */
.form-group.has-error .form-control {
    border-color: #EF4444;
}
.form-group.has-error .form-control:focus {
    box-shadow: 0 0 0 3px rgba(239,68,68,0.1);
}
.form-group.has-success .form-control {
    border-color: #10B981;
}
.form-group.has-success .form-control:focus {
    box-shadow: 0 0 0 3px rgba(16,185,129,0.1);
}
.form-group .error-message {
    font-size: 12px;
    color: #EF4444;
    margin-top: 6px;
    display: flex;
    align-items: center;
    gap: 4px;
}
.form-group .success-message {
    font-size: 12px;
    color: #10B981;
    margin-top: 6px;
    display: flex;
    align-items: center;
    gap: 4px;
}

/* 徽章增强 */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.badge-primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.badge-success {
    background: linear-gradient(135deg, #10B981, #059669);
    color: white;
}
.badge-danger {
    background: linear-gradient(135deg, #EF4444, #DC2626);
    color: white;
}
.badge-warning {
    background: linear-gradient(135deg, #F59E0B, #D97706);
    color: white;
}
.badge-info {
    background: linear-gradient(135deg, #06B6D4, #0891B2);
    color: white;
}

/* 卡片 hover 增强 */
.card-hover {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.card-hover:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.12);
}

/* 渐变边框卡片 */
.gradient-border-card {
    position: relative;
    background: white;
    border-radius: 16px;
    padding: 24px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.04);
}
.gradient-border-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 4px;
    background: linear-gradient(90deg, #4F46E5, #7C3AED, #06B6D4);
    border-radius: 16px 16px 0 0;
}

/* 图标按钮 */
.icon-btn {
    width: 40px;
    height: 40px;
    border-radius: 10px;
    border: none;
    background: #F3F4F6;
    color: #6B7280;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
}
.icon-btn:hover {
    background: #E5E7EB;
    color: #1F2937;
    transform: translateY(-2px);
}
.icon-btn.primary {
    background: #EEF2FF;
    color: #4F46E5;
}
.icon-btn.primary:hover {
    background: #E0E7FF;
}
.icon-btn.danger {
    background: #FEF2F2;
    color: #EF4444;
}
.icon-btn.danger:hover {
    background: #FEE2E2;
}

/* 分割线 */
.divider {
    height: 1px;
    background: #E5E7EB;
    margin: 20px 0;
}
.divider-vertical {
    width: 1px;
    height: 20px;
    background: #E5E7EB;
    display: inline-block;
    margin: 0 12px;
}

/* 文本截断 */
.text-truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.text-clamp-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}
.text-clamp-3 {
    display: -webkit-box;
    -webkit-line-clamp: 3;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* Flex 工具类 */
.flex { display: flex; }
.flex-col { flex-direction: column; }
.flex-wrap { flex-wrap: wrap; }
.items-center { align-items: center; }
.justify-center { justify-content: center; }
.justify-between { justify-content: space-between; }
.gap-1 { gap: 4px; }
.gap-2 { gap: 8px; }
.gap-3 { gap: 12px; }
.gap-4 { gap: 16px; }
.gap-5 { gap: 20px; }

/* 间距工具类 */
.m-0 { margin: 0; }
.mt-1 { margin-top: 4px; }
.mt-2 { margin-top: 8px; }
.mt-3 { margin-top: 12px; }
.mt-4 { margin-top: 16px; }
.mt-5 { margin-top: 20px; }
.mb-1 { margin-bottom: 4px; }
.mb-2 { margin-bottom: 8px; }
.mb-3 { margin-bottom: 12px; }
.mb-4 { margin-bottom: 16px; }
.mb-5 { margin-bottom: 20px; }
.p-0 { padding: 0; }
.p-1 { padding: 4px; }
.p-2 { padding: 8px; }
.p-3 { padding: 12px; }
.p-4 { padding: 16px; }
.p-5 { padding: 20px; }

/* 文本工具类 */
.text-center { text-align: center; }
.text-left { text-align: left; }
.text-right { text-align: right; }
.font-bold { font-weight: 700; }
.font-semibold { font-weight: 600; }
.font-medium { font-weight: 500; }
.text-sm { font-size: 13px; }
.text-base { font-size: 14px; }
.text-lg { font-size: 16px; }
.text-xl { font-size: 18px; }
.text-2xl { font-size: 20px; }
.text-3xl { font-size: 24px; }

/* 隐藏/显示 */
.hidden { display: none; }
.block { display: block; }
.inline-block { display: inline-block; }
.inline { display: inline; }

/* 圆角工具类 */
.rounded { border-radius: 8px; }
.rounded-lg { border-radius: 12px; }
.rounded-xl { border-radius: 16px; }
.rounded-full { border-radius: 50%; }

/* 阴影工具类 */
.shadow { box-shadow: 0 1px 3px rgba(0,0,0,0.1); }
.shadow-md { box-shadow: 0 4px 6px rgba(0,0,0,0.1); }
.shadow-lg { box-shadow: 0 10px 25px rgba(0,0,0,0.1); }
.shadow-xl { box-shadow: 0 20px 50px rgba(0,0,0,0.15); }

/* 光标工具类 */
.cursor-pointer { cursor: pointer; }
.cursor-not-allowed { cursor: not-allowed; }

/* 溢出工具类 */
.overflow-hidden { overflow: hidden; }
.overflow-auto { overflow: auto; }

/* 宽度工具类 */
.w-full { width: 100%; }
.w-auto { width: auto; }
.max-w-full { max-width: 100%; }

/* 高度工具类 */
.h-full { height: 100%; }
.min-h-screen { min-height: 100vh; }

/* ================================================================
   ===== 商业级 UI 增强：侧边栏、表格、表单、分页 =====
   ================================================================ */

/* 管理后台侧边栏增强 */
.admin-sidebar {
    background: linear-gradient(180deg, #0F172A 0%, #1E293B 50%, #0F172A 100%);
    border-right: 1px solid rgba(255,255,255,0.05);
    box-shadow: 4px 0 20px rgba(0,0,0,0.1);
    transition: width 0.3s ease;
}
.admin-sidebar .logo {
    padding: 24px 20px;
    border-bottom: 1px solid rgba(255,255,255,0.08);
}
.admin-sidebar .logo a {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
    font-size: 16px;
    font-weight: 700;
    color: white;
    text-decoration: none;
}
.admin-sidebar .logo a::before {
    content: "📚";
    font-size: 24px;
}
.admin-menu {
    list-style: none;
    padding: 12px 0;
    margin: 0;
}
.admin-menu li a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    color: #94A3B8;
    font-size: 13px;
    font-weight: 500;
    border-left: 3px solid transparent;
    transition: all 0.2s ease;
}
.admin-menu li a:hover {
    background: rgba(255,255,255,0.05);
    color: white;
    border-left-color: #4F46E5;
}
.admin-menu li a.active {
    background: linear-gradient(90deg, rgba(79,70,229,0.15), transparent);
    color: white;
    border-left-color: #4F46E5;
}
.admin-menu li a i {
    width: 18px;
    text-align: center;
    font-size: 15px;
}
.admin-menu li.section-title {
    padding: 16px 20px 6px;
    font-size: 10px;
    color: #64748B;
    text-transform: uppercase;
    letter-spacing: 1px;
    font-weight: 600;
}

/* 管理后台内容区 */
.admin-content {
    background: linear-gradient(135deg, #F8FAFC 0%, #F1F5F9 100%);
    min-height: 100vh;
}

/* 管理后台头部 */
.admin-header {
    background: white;
    border-bottom: 1px solid #E2E8F0;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    padding: 14px 24px;
    display: flex;
    justify-content: space-between;
    align-items: center;
}
.admin-header h3 {
    margin: 0;
    font-size: 16px;
    font-weight: 700;
    color: #1F2937;
}

/* 表格容器增强 */
.table-container {
    background: white;
    border-radius: 16px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    overflow: hidden;
    padding: 20px;
}
.table-container h3 {
    padding: 0 0 16px;
    margin: 0;
    font-size: 15px;
    font-weight: 700;
    color: #1F2937;
    border-bottom: 2px solid #F1F5F9;
    display: flex;
    align-items: center;
    gap: 8px;
}
.table-container h3 i {
    color: #4F46E5;
}

/* 表格增强 */
.table {
    width: 100%;
    border-collapse: collapse;
}
.table th {
    padding: 12px 14px;
    font-size: 11px;
    font-weight: 600;
    color: #64748B;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    background: #F8FAFC;
    border-bottom: 2px solid #E2E8F0;
}
.table td {
    padding: 12px 14px;
    font-size: 13px;
    color: #334155;
    border-bottom: 1px solid #F1F5F9;
    vertical-align: middle;
}
.table tbody tr {
    transition: all 0.2s ease;
}
.table tbody tr:hover {
    background: linear-gradient(90deg, #F8FAFC, #F1F5F9);
}
.table tbody tr:last-child td {
    border-bottom: none;
}

/* 统计卡片增强 */
.stat-card {
    background: white;
    border-radius: 16px;
    padding: 20px;
    text-align: center;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
    position: relative;
    overflow: hidden;
}
.stat-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #4F46E5, #7C3AED);
    opacity: 0;
    transition: opacity 0.3s ease;
}
.stat-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 25px rgba(0,0,0,0.1);
}
.stat-card:hover::before {
    opacity: 1;
}
.stat-card .stat-icon {
    font-size: 32px;
    margin-bottom: 12px;
    opacity: 0.9;
}
.stat-card .stat-value {
    font-size: 28px;
    font-weight: 800;
    background: linear-gradient(135deg, #1F2937, #374151);
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
    background-clip: text;
}
.stat-card .stat-title {
    color: #6B7280;
    font-size: 13px;
    font-weight: 500;
    margin-top: 6px;
}

/* 快捷操作按钮增强 */
.table-container .row .btn-block {
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    transition: all 0.2s ease;
}
.table-container .row .btn-block:hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

/* 搜索/筛选区域增强 */
.form-inline {
    display: flex;
    flex-wrap: wrap;
    gap: 10px;
    align-items: center;
}
.form-inline .form-group {
    margin-bottom: 0;
}

/* 表单控件增强 */
.form-control {
    display: block;
    width: 100%;
    padding: 10px 14px;
    font-size: 13px;
    line-height: 1.5;
    color: #334155;
    background: white;
    border: 1px solid #E2E8F0;
    border-radius: 8px;
    transition: all 0.2s ease;
}
.form-control:focus {
    border-color: #4F46E5;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
    outline: none;
}
.form-control::placeholder {
    color: #94A3B8;
}

/* 按钮增强 */
.btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 6px;
    padding: 8px 16px;
    font-size: 13px;
    font-weight: 600;
    border-radius: 8px;
    border: none;
    cursor: pointer;
    transition: all 0.2s ease;
    text-decoration: none;
}
.btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 12px rgba(0,0,0,0.12);
}
.btn-primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.btn-success {
    background: linear-gradient(135deg, #10B981, #059669);
    color: white;
}
.btn-danger {
    background: linear-gradient(135deg, #EF4444, #DC2626);
    color: white;
}
.btn-warning {
    background: linear-gradient(135deg, #F59E0B, #D97706);
    color: white;
}
.btn-info {
    background: linear-gradient(135deg, #06B6D4, #0891B2);
    color: white;
}
.btn-default {
    background: #F1F5F9;
    color: #475569;
    border: 1px solid #E2E8F0;
}
.btn-default:hover {
    background: #E2E8F0;
}
.btn-xs {
    padding: 5px 10px;
    font-size: 11px;
    border-radius: 6px;
}
.btn-block {
    display: flex;
    width: 100%;
}

/* 标签增强 */
.label {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 8px;
    border-radius: 6px;
    font-size: 11px;
    font-weight: 600;
}
.label-success {
    background: rgba(16,185,129,0.1);
    color: #059669;
}
.label-danger {
    background: rgba(239,68,68,0.1);
    color: #DC2626;
}
.label-warning {
    background: rgba(245,158,11,0.1);
    color: #D97706;
}
.label-info {
    background: rgba(6,182,212,0.1);
    color: #0891B2;
}
.label-default {
    background: #F1F5F9;
    color: #64748B;
}
.label-primary {
    background: rgba(79,70,229,0.1);
    color: #4F46E5;
}

/* 警告框增强 */
.alert {
    border-radius: 10px;
    border: none;
    padding: 14px 18px;
    display: flex;
    align-items: center;
    gap: 10px;
    margin-bottom: 16px;
    font-size: 13px;
}
.alert-success {
    background: rgba(16,185,129,0.1);
    color: #065F46;
    border-left: 3px solid #10B981;
}
.alert-danger {
    background: rgba(239,68,68,0.1);
    color: #991B1B;
    border-left: 3px solid #EF4444;
}
.alert-warning {
    background: rgba(245,158,11,0.1);
    color: #92400E;
    border-left: 3px solid #F59E0B;
}
.alert-info {
    background: rgba(6,182,212,0.1);
    color: #155E75;
    border-left: 3px solid #06B6D4;
}

/* 面板增强 */
.panel {
    background: white;
    border-radius: 12px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    overflow: hidden;
    margin-bottom: 20px;
}
.panel-heading {
    padding: 14px 20px;
    background: linear-gradient(135deg, #F8FAFC, #F1F5F9);
    border-bottom: 2px solid #E2E8F0;
    display: flex;
    align-items: center;
    justify-content: space-between;
}
.panel-heading h3,
.panel-heading .panel-title {
    margin: 0;
    font-size: 14px;
    font-weight: 700;
    color: #1F2937;
    display: flex;
    align-items: center;
    gap: 8px;
}
.panel-body {
    padding: 20px;
}

/* 分页增强 */
.pagination {
    display: flex;
    justify-content: center;
    gap: 6px;
    margin-top: 20px;
}
.pagination > li > a,
.pagination > li > span {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    height: 36px;
    padding: 6px 10px;
    border-radius: 8px;
    font-size: 13px;
    font-weight: 500;
    text-decoration: none;
    transition: all 0.2s ease;
    border: 1px solid #E5E7EB;
    color: #4B5563;
    background: white;
}
.pagination > li > a:hover {
    background: #4F46E5;
    color: white;
    border-color: #4F46E5;
}
.pagination > .active > a,
.pagination > .active > span {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border-color: transparent;
}

/* 进度条增强 */
.progress {
    height: 8px;
    border-radius: 8px;
    background: #E5E7EB;
    overflow: hidden;
}
.progress-bar {
    background: linear-gradient(90deg, #4F46E5, #7C3AED);
    border-radius: 8px;
    transition: width 0.5s ease;
}

/* 模态框增强 */
.modal-content {
    border-radius: 16px;
    border: none;
    box-shadow: 0 25px 50px -12px rgba(0,0,0,0.25);
}
.modal-header {
    border-bottom: 1px solid #E5E7EB;
    padding: 16px 20px;
}
.modal-header .modal-title {
    font-size: 16px;
    font-weight: 700;
}
.modal-body {
    padding: 20px;
}
.modal-footer {
    border-top: 1px solid #E5E7EB;
    padding: 14px 20px;
}

/* 空状态增强 */
.empty-state {
    text-align: center;
    padding: 50px 20px;
    color: #9CA3AF;
}
.empty-state i {
    font-size: 48px;
    margin-bottom: 16px;
    display: block;
    color: #D1D5DB;
}
.empty-state p {
    font-size: 14px;
    margin-bottom: 8px;
}

/* 表格空状态 */
.table-empty {
    text-align: center;
    padding: 40px 20px;
    color: #9CA3AF;
}
.table-empty i {
    font-size: 36px;
    margin-bottom: 12px;
    display: block;
    color: #D1D5DB;
}

/* 下拉菜单增强 */
.dropdown-menu {
    border-radius: 10px;
    border: 1px solid #E5E7EB;
    box-shadow: 0 10px 40px rgba(0,0,0,0.12);
    padding: 6px;
    min-width: 160px;
}
.dropdown-menu > li > a {
    padding: 8px 14px;
    border-radius: 6px;
    font-size: 13px;
    color: #4B5563;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 8px;
}
.dropdown-menu > li > a:hover {
    background: #F3F4F6;
    color: #1F2937;
}

/* 表单验证状态 */
.form-group.has-error .form-control {
    border-color: #EF4444;
}
.form-group.has-error .form-control:focus {
    box-shadow: 0 0 0 3px rgba(239,68,68,0.1);
}
.form-group.has-success .form-control {
    border-color: #10B981;
}
.form-group .error-message {
    font-size: 12px;
    color: #EF4444;
    margin-top: 4px;
}

/* 卡片 hover 增强 */
.card-hover {
    transition: all 0.3s cubic-bezier(0.4, 0, 0.2, 1);
}
.card-hover:hover {
    transform: translateY(-4px);
    box-shadow: 0 12px 40px rgba(0,0,0,0.12);
}

/* 渐变边框卡片 */
.gradient-border-card {
    position: relative;
    background: white;
    border-radius: 12px;
    padding: 20px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.05);
}
.gradient-border-card::before {
    content: '';
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: linear-gradient(90deg, #4F46E5, #7C3AED, #06B6D4);
    border-radius: 12px 12px 0 0;
}

/* 图标按钮 */
.icon-btn {
    width: 36px;
    height: 36px;
    border-radius: 8px;
    border: none;
    background: #F3F4F6;
    color: #6B7280;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    transition: all 0.2s ease;
}
.icon-btn:hover {
    background: #E5E7EB;
    color: #1F2937;
}
.icon-btn.primary {
    background: #EEF2FF;
    color: #4F46E5;
}
.icon-btn.danger {
    background: #FEF2F2;
    color: #EF4444;
}

/* 工具提示增强 */
.tooltip-inner {
    background: #1F2937;
    border-radius: 8px;
    padding: 6px 12px;
    font-size: 12px;
    font-weight: 500;
    box-shadow: 0 4px 12px rgba(0,0,0,0.15);
}

/* 徽章增强 */
.badge {
    display: inline-flex;
    align-items: center;
    gap: 4px;
    padding: 3px 8px;
    border-radius: 16px;
    font-size: 10px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}
.badge-primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.badge-success {
    background: linear-gradient(135deg, #10B981, #059669);
    color: white;
}
.badge-danger {
    background: linear-gradient(135deg, #EF4444, #DC2626);
    color: white;
}
.badge-warning {
    background: linear-gradient(135deg, #F59E0B, #D97706);
    color: white;
}
.badge-info {
    background: linear-gradient(135deg, #06B6D4, #0891B2);
    color: white;
}

/* 骨架屏加载动画 */
.skeleton {
    background: linear-gradient(90deg, #f0f0f0 25%, #e0e0e0 50%, #f0f0f0 75%);
    background-size: 200% 100%;
    animation: skeleton-loading 1.5s infinite;
    border-radius: 6px;
}
@keyframes skeleton-loading {
    0% { background-position: 200% 0; }
    100% { background-position: -200% 0; }
}
.skeleton-text { height: 12px; margin-bottom: 6px; }
.skeleton-title { height: 20px; width: 60%; margin-bottom: 10px; }
.skeleton-avatar { width: 40px; height: 40px; border-radius: 50%; }

/* 加载动画 */
.loading-spinner {
    width: 40px;
    height: 40px;
    border: 3px solid #E5E7EB;
    border-top-color: #4F46E5;
    border-radius: 50%;
    animation: spin 1s linear infinite;
}
@keyframes spin {
    to { transform: rotate(360deg); }
}

/* 提示框 Toast */
.toast-container {
    position: fixed;
    top: 20px;
    right: 20px;
    z-index: 10000;
    display: flex;
    flex-direction: column;
    gap: 8px;
}
.toast {
    background: white;
    border-radius: 10px;
    padding: 14px 18px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.15);
    display: flex;
    align-items: center;
    gap: 10px;
    min-width: 280px;
    max-width: 360px;
    animation: toast-slide-in 0.3s ease;
    border-left: 3px solid transparent;
}
.toast.success { border-left-color: #10B981; }
.toast.error { border-left-color: #EF4444; }
.toast.warning { border-left-color: #F59E0B; }
.toast.info { border-left-color: #06B6D4; }
.toast .toast-icon { font-size: 18px; }
.toast.success .toast-icon { color: #10B981; }
.toast.error .toast-icon { color: #EF4444; }
.toast.warning .toast-icon { color: #F59E0B; }
.toast.info .toast-icon { color: #06B6D4; }
.toast .toast-content { flex: 1; }
.toast .toast-title { font-weight: 600; color: #1F2937; font-size: 13px; }
.toast .toast-message { font-size: 12px; color: #6B7280; }
.toast .toast-close {
    background: none;
    border: none;
    color: #9CA3AF;
    cursor: pointer;
    padding: 2px;
    font-size: 14px;
}
@keyframes toast-slide-in {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

/* 文本截断 */
.text-truncate {
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.text-clamp-2 {
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

/* 响应式优化 */
@media (max-width: 992px) {
    .admin-sidebar {
        width: 70px;
    }
    .admin-sidebar .logo a {
        font-size: 0;
    }
    .admin-sidebar .logo a::before {
        font-size: 20px;
    }
    .admin-content {
        margin-left: 70px;
    }
    .admin-menu li a span {
        display: none;
    }
    .admin-menu li.section-title {
        display: none;
    }
}
@media (max-width: 768px) {
    .admin-sidebar {
        width: 56px;
    }
    .admin-sidebar .logo a {
        font-size: 0;
    }
    .admin-sidebar .logo a::before {
        font-size: 18px;
    }
    .admin-content {
        margin-left: 56px;
    }
    .admin-header {
        padding: 10px 14px;
    }
    .admin-header h3 {
        font-size: 14px;
    }
    .stat-card {
        padding: 14px;
    }
    .stat-card .stat-value {
        font-size: 22px;
    }
    .table-container {
        padding: 14px;
    }
    .table-container h3 {
        font-size: 13px;
    }
    .table th, .table td {
        padding: 8px 10px;
        font-size: 11px;
    }
    .btn-xs {
        padding: 4px 8px;
        font-size: 10px;
    }
    .form-inline {
        flex-direction: column;
        align-items: stretch;
    }
    .form-inline .form-group {
        width: 100%;
    }
}
@media (max-width: 576px) {
    .stat-card .stat-icon {
        font-size: 24px;
        margin-bottom: 8px;
    }
    .stat-card .stat-value {
        font-size: 20px;
    }
    .stat-card .stat-title {
        font-size: 11px;
    }
    .table-container .row .btn-block {
        margin-bottom: 8px;
    }
}

/* ================================================================
   ===== 教育平台风格首页 UI =====
   ================================================================ */

/* 英雄区域 */
.edu-hero {
    position: relative;
    background: linear-gradient(135deg, #1E3A5F 0%, #0D2137 50%, #1A365D 100%);
    padding: 80px 0 60px;
    overflow: hidden;
}
.edu-hero-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.05)" stroke-width="0.5"/></svg>') repeat;
    background-size: 80px;
}
.edu-hero-content {
    position: relative;
    z-index: 1;
    display: flex;
    flex-direction: column;
    align-items: center;
    text-align: center;
}
.edu-hero-text h1 {
    font-size: 42px;
    font-weight: 800;
    color: white;
    margin-bottom: 12px;
    text-shadow: 0 2px 10px rgba(0,0,0,0.3);
}
.edu-hero-text p {
    font-size: 18px;
    color: rgba(255,255,255,0.9);
    margin-bottom: 30px;
}

/* 搜索框 */
.edu-hero-search {
    width: 100%;
    max-width: 600px;
    margin-bottom: 30px;
}
.edu-search-box {
    display: flex;
    background: white;
    border-radius: 12px;
    overflow: hidden;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
}
.edu-search-box i {
    display: flex;
    align-items: center;
    padding: 0 20px;
    color: #9CA3AF;
    font-size: 18px;
}
.edu-search-box input {
    flex: 1;
    border: none;
    padding: 18px 0;
    font-size: 16px;
    outline: none;
}
.edu-search-box button {
    padding: 18px 32px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border: none;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}
.edu-search-box button:hover {
    background: linear-gradient(135deg, #7C3AED, #4F46E5);
}
.edu-search-tags {
    margin-top: 12px;
    color: rgba(255,255,255,0.7);
    font-size: 14px;
}
.edu-search-tags span {
    margin-right: 8px;
}
.edu-search-tags a {
    color: rgba(255,255,255,0.9);
    margin-right: 12px;
    padding: 4px 12px;
    border-radius: 20px;
    background: rgba(255,255,255,0.1);
    transition: all 0.3s ease;
}
.edu-search-tags a:hover {
    background: rgba(255,255,255,0.2);
    color: white;
}

/* 英雄统计 */
.edu-hero-stats {
    display: flex;
    gap: 40px;
    justify-content: center;
}
.edu-stat {
    text-align: center;
}
.edu-stat-num {
    font-size: 36px;
    font-weight: 800;
    color: white;
}
.edu-stat-text {
    font-size: 14px;
    color: rgba(255,255,255,0.8);
    margin-top: 4px;
}

/* 课程分类 */
.edu-categories {
    background: white;
    padding: 50px 0;
}
.edu-section-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 30px;
}
.edu-section-header h2 {
    font-size: 24px;
    font-weight: 700;
    color: #1F2937;
    margin: 0;
}
.edu-section-header a {
    color: #4F46E5;
    font-size: 14px;
    font-weight: 600;
}
.edu-section-header a:hover {
    color: #3730A3;
}
.edu-category-grid {
    display: grid;
    grid-template-columns: repeat(6, 1fr);
    gap: 20px;
}
.edu-cat-item {
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 12px;
    padding: 24px 16px;
    border-radius: 12px;
    text-decoration: none;
    transition: all 0.3s ease;
}
.edu-cat-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}
.edu-cat-icon {
    width: 60px;
    height: 60px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
}
.edu-cat-item span {
    font-size: 14px;
    font-weight: 600;
    color: #1F2937;
}

/* 精品课程 */
.edu-courses {
    background: #F8FAFC;
    padding: 60px 0;
}
.edu-course-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.edu-course-card {
    background: white;
    border-radius: 16px;
    overflow: hidden;
    text-decoration: none;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
}
.edu-course-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.12);
}
.edu-course-cover {
    position: relative;
    height: 160px;
    overflow: hidden;
}
.edu-course-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.edu-course-cover-fallback {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #4F46E5, #06B6D4);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 40px;
}
.edu-course-tag {
    position: absolute;
    top: 12px;
    left: 12px;
    background: rgba(0,0,0,0.7);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
}
.edu-course-info {
    padding: 16px;
}
.edu-course-info h4 {
    font-size: 15px;
    font-weight: 600;
    color: #1F2937;
    margin: 0 0 8px;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.edu-course-meta {
    display: flex;
    gap: 16px;
    font-size: 13px;
    color: #6B7280;
}
.edu-course-meta i {
    margin-right: 4px;
}
.edu-more-btn {
    text-align: center;
    margin-top: 30px;
}
.edu-more-btn a {
    display: inline-block;
    padding: 12px 40px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border-radius: 30px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
}
.edu-more-btn a:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 20px rgba(79,70,229,0.3);
}

/* 培训机构 */
.edu-schools {
    background: white;
    padding: 60px 0;
}
.edu-school-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.edu-school-card {
    background: white;
    border-radius: 16px;
    padding: 24px;
    text-align: center;
    text-decoration: none;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    border: 1px solid #F1F5F9;
    transition: all 0.3s ease;
}
.edu-school-card:hover {
    transform: translateY(-6px);
    box-shadow: 0 12px 30px rgba(0,0,0,0.12);
}
.edu-school-logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 16px;
    border-radius: 50%;
    overflow: hidden;
}
.edu-school-logo img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.edu-school-logo-fallback {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #EEF2FF, #E0E7FF);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #4F46E5;
    font-size: 32px;
}
.edu-school-info h4 {
    font-size: 16px;
    font-weight: 600;
    color: #1F2937;
    margin: 0 0 8px;
}
.edu-school-rating {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 2px;
    margin-bottom: 8px;
}
.edu-school-rating i {
    color: #F59E0B;
    font-size: 14px;
}
.edu-school-rating i.empty {
    color: #D1D5DB;
}
.edu-school-rating span {
    font-size: 13px;
    color: #6B7280;
    margin-left: 4px;
}
.edu-school-meta {
    font-size: 13px;
    color: #6B7280;
}

/* 平台优势 */
.edu-advantages {
    background: linear-gradient(135deg, #EEF2FF, #E0E7FF);
    padding: 60px 0;
}
.edu-advantage-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 24px;
}
.edu-advantage-item {
    background: white;
    border-radius: 16px;
    padding: 30px 20px;
    text-align: center;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    transition: all 0.3s ease;
}
.edu-advantage-item:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 25px rgba(0,0,0,0.1);
}
.edu-advantage-icon {
    width: 70px;
    height: 70px;
    margin: 0 auto 16px;
    border-radius: 50%;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 28px;
}
.edu-advantage-item h4 {
    font-size: 18px;
    font-weight: 700;
    color: #1F2937;
    margin: 0 0 8px;
}
.edu-advantage-item p {
    font-size: 14px;
    color: #6B7280;
    margin: 0;
}

/* 平台动态 + 登录 */
.edu-news {
    background: white;
    padding: 60px 0;
}
.edu-news-layout {
    display: grid;
    grid-template-columns: 2fr 1fr;
    gap: 40px;
}
.edu-news-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.edu-news-list li {
    display: flex;
    align-items: center;
    padding: 14px 0;
    border-bottom: 1px solid #F1F5F9;
}
.edu-news-list li:last-child {
    border-bottom: none;
}
.edu-news-date {
    display: inline-block;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    padding: 4px 12px;
    border-radius: 20px;
    font-size: 12px;
    font-weight: 600;
    margin-right: 12px;
    white-space: nowrap;
}
.edu-news-list li a {
    color: #1F2937;
    font-size: 14px;
    text-decoration: none;
    transition: color 0.3s ease;
}
.edu-news-list li a:hover {
    color: #4F46E5;
}

/* 登录框 */
.edu-login-box {
    background: #F8FAFC;
    border-radius: 16px;
    padding: 30px;
}
.edu-login-tabs {
    text-align: center;
    margin-bottom: 20px;
    padding-bottom: 12px;
    border-bottom: 2px solid #E5E7EB;
}
.edu-login-tabs span {
    font-size: 18px;
    font-weight: 700;
    color: #1F2937;
}
.edu-login-field {
    position: relative;
    margin-bottom: 16px;
}
.edu-login-field i {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #9CA3AF;
}
.edu-login-field input {
    width: 100%;
    padding: 14px 16px 14px 44px;
    border: 2px solid #E5E7EB;
    border-radius: 10px;
    font-size: 14px;
    transition: all 0.3s ease;
}
.edu-login-field input:focus {
    border-color: #4F46E5;
    outline: none;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
}
.edu-login-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border: none;
    border-radius: 10px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}
.edu-login-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(79,70,229,0.3);
}
.edu-login-footer {
    display: flex;
    justify-content: space-between;
    margin-top: 16px;
    font-size: 14px;
}
.edu-login-footer a {
    color: #4F46E5;
    text-decoration: none;
}
.edu-login-footer a:hover {
    color: #3730A3;
}
.edu-login-welcome {
    text-align: center;
    padding: 20px;
}
.edu-login-avatar {
    width: 70px;
    height: 70px;
    border-radius: 50%;
    background: linear-gradient(135deg, #4F46E5, #06B6D4);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 28px;
    font-weight: 700;
    margin: 0 auto 12px;
}
.edu-login-welcome p {
    font-weight: 600;
    color: #1F2937;
    margin-bottom: 12px;
}
.edu-login-welcome a {
    display: inline-block;
    padding: 10px 24px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border-radius: 8px;
    text-decoration: none;
    font-weight: 600;
}

/* 底部信任 */
.edu-trust {
    background: #F8FAFC;
    padding: 30px 0;
    border-top: 1px solid #E5E7EB;
}
.edu-trust-list {
    display: flex;
    justify-content: center;
    gap: 40px;
}
.edu-trust-item {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #6B7280;
}
.edu-trust-item i {
    color: #10B981;
    font-size: 18px;
}

/* 响应式 */
@media (max-width: 992px) {
    .edu-category-grid { grid-template-columns: repeat(3, 1fr); }
    .edu-course-grid { grid-template-columns: repeat(2, 1fr); }
    .edu-school-grid { grid-template-columns: repeat(2, 1fr); }
    .edu-advantage-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .edu-hero-text h1 { font-size: 28px; }
    .edu-hero-stats { flex-wrap: wrap; gap: 20px; }
    .edu-category-grid { grid-template-columns: repeat(3, 1fr); }
    .edu-course-grid { grid-template-columns: 1fr; }
    .edu-school-grid { grid-template-columns: 1fr; }
    .edu-advantage-grid { grid-template-columns: 1fr; }
    .edu-news-layout { grid-template-columns: 1fr; }
    .edu-trust-list { flex-wrap: wrap; gap: 20px; }
}
@media (max-width: 576px) {
    .edu-hero { padding: 40px 0 30px; }
    .edu-hero-text h1 { font-size: 24px; }
    .edu-search-box { flex-direction: column; }
    .edu-search-box input { padding: 14px 16px; }
    .edu-search-box button { padding: 14px; }
    .edu-stat-num { font-size: 28px; }
    .edu-category-grid { grid-template-columns: repeat(2, 1fr); }
}

/* ================================================================
   ===== 课程列表页面 UI =====
   ================================================================ */

/* 面包屑 */
.edu-breadcrumb {
    background: #F8FAFC;
    padding: 16px 0;
    border-bottom: 1px solid #E5E7EB;
}
.edu-breadcrumb-inner {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #6B7280;
}
.edu-breadcrumb-inner a {
    color: #4F46E5;
    text-decoration: none;
}
.edu-breadcrumb-inner a:hover {
    color: #3730A3;
}
.edu-breadcrumb-sep {
    color: #D1D5DB;
}

/* 搜索结果提示 */
.edu-search-result {
    padding: 16px 0;
    background: #EEF2FF;
}
.edu-search-result-box {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 14px 20px;
    background: white;
    border-radius: 12px;
    border-left: 4px solid #4F46E5;
    font-size: 14px;
}
.edu-search-result-box i {
    color: #4F46E5;
    font-size: 18px;
}
.edu-clear-btn {
    margin-left: auto;
    padding: 6px 14px;
    background: #F3F4F6;
    border-radius: 8px;
    font-size: 13px;
    color: #6B7280;
    text-decoration: none;
    transition: all 0.3s ease;
}
.edu-clear-btn:hover {
    background: #E5E7EB;
    color: #1F2937;
}

/* 筛选区域 */
.edu-filter {
    background: white;
    padding: 24px 0;
    border-bottom: 1px solid #E5E7EB;
}
.edu-filter-box {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.edu-filter-item {
    display: flex;
    align-items: center;
    gap: 12px;
}
.edu-filter-label {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 14px;
    font-weight: 600;
    color: #374151;
    min-width: 80px;
}
.edu-filter-label i {
    color: #4F46E5;
}
.edu-filter-options {
    display: flex;
    flex-wrap: wrap;
    gap: 8px;
}
.edu-filter-options a {
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    color: #4B5563;
    text-decoration: none;
    background: #F3F4F6;
    transition: all 0.3s ease;
}
.edu-filter-options a:hover {
    background: #E5E7EB;
    color: #1F2937;
}
.edu-filter-options a.active {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}

/* 课程列表头部 */
.edu-course-list {
    background: #F8FAFC;
    padding: 30px 0 60px;
    min-height: 500px;
}
.edu-list-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}
.edu-list-count {
    font-size: 14px;
    color: #6B7280;
}
.edu-list-count strong {
    color: #1F2937;
    font-weight: 700;
}
.edu-list-actions {
    display: flex;
    gap: 12px;
    align-items: center;
}
.edu-view-toggle {
    display: flex;
    border: 1px solid #E5E7EB;
    border-radius: 8px;
    overflow: hidden;
}
.edu-view-btn {
    padding: 8px 12px;
    border: none;
    background: white;
    color: #6B7280;
    cursor: pointer;
    transition: all 0.3s ease;
}
.edu-view-btn:hover {
    background: #F3F4F6;
}
.edu-view-btn.active {
    background: #4F46E5;
    color: white;
}

/* 课程卡片增强 */
.edu-course-badge {
    position: absolute;
    top: 12px;
    right: 12px;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 11px;
    font-weight: 700;
    color: white;
}
.edu-course-badge.hot {
    background: linear-gradient(135deg, #EF4444, #DC2626);
}
.edu-course-badge.free {
    background: linear-gradient(135deg, #10B981, #059669);
}
.edu-course-school {
    margin-top: 8px;
    font-size: 12px;
    color: #9CA3AF;
}
.edu-course-school i {
    margin-right: 4px;
}

/* 列表视图 */
.edu-course-grid.list-view {
    display: flex;
    flex-direction: column;
    gap: 16px;
}
.edu-course-grid.list-view .edu-course-card {
    display: flex;
    flex-direction: row;
}
.edu-course-grid.list-view .edu-course-cover {
    width: 240px;
    height: 160px;
    flex-shrink: 0;
}
.edu-course-grid.list-view .edu-course-info {
    flex: 1;
    display: flex;
    flex-direction: column;
    justify-content: center;
}
.edu-course-grid.list-view .edu-course-info h4 {
    white-space: normal;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    display: -webkit-box;
}

/* 空状态 */
.edu-empty-state {
    text-align: center;
    padding: 80px 20px;
    background: white;
    border-radius: 16px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
}
.edu-empty-icon {
    width: 100px;
    height: 100px;
    border-radius: 50%;
    background: #EEF2FF;
    display: flex;
    align-items: center;
    justify-content: center;
    margin: 0 auto 24px;
}
.edu-empty-icon i {
    font-size: 40px;
    color: #4F46E5;
}
.edu-empty-state h3 {
    font-size: 20px;
    font-weight: 700;
    color: #1F2937;
    margin: 0 0 8px;
}
.edu-empty-state p {
    font-size: 14px;
    color: #6B7280;
    margin: 0 0 20px;
}
.edu-empty-btn {
    display: inline-block;
    padding: 12px 28px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border-radius: 10px;
    font-weight: 600;
    text-decoration: none;
    transition: all 0.3s ease;
}
.edu-empty-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(79,70,229,0.3);
}

/* 响应式 */
@media (max-width: 992px) {
    .edu-course-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .edu-course-grid { grid-template-columns: 1fr; }
    .edu-filter-item { flex-direction: column; align-items: flex-start; }
    .edu-list-header { flex-direction: column; gap: 12px; }
    .edu-course-grid.list-view .edu-course-card { flex-direction: column; }
    .edu-course-grid.list-view .edu-course-cover { width: 100%; }
}
@media (max-width: 576px) {
    .edu-filter-options a { padding: 6px 12px; font-size: 12px; }
}

/* ================================================================
   ===== 课程详情页面 UI =====
   ================================================================ */

/* 课程头部 */
.edu-detail-header {
    background: white;
    padding: 40px 0;
    border-bottom: 1px solid #E5E7EB;
}
.edu-detail-layout {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 40px;
    align-items: start;
}
.edu-detail-cover {
    position: relative;
    border-radius: 16px;
    overflow: hidden;
    box-shadow: 0 10px 30px rgba(0,0,0,0.1);
}
.edu-detail-cover img {
    width: 100%;
    height: 300px;
    object-fit: cover;
}
.edu-detail-cover-fallback {
    width: 100%;
    height: 300px;
    background: linear-gradient(135deg, #EEF2FF, #E0E7FF);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #4F46E5;
    font-size: 60px;
}
.edu-detail-tag {
    position: absolute;
    top: 16px;
    left: 16px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
}
.edu-detail-badge {
    position: absolute;
    top: 16px;
    right: 16px;
    padding: 6px 16px;
    border-radius: 20px;
    font-size: 14px;
    font-weight: 700;
    color: white;
}
.edu-detail-badge.free {
    background: linear-gradient(135deg, #10B981, #059669);
}
.edu-detail-badge.price {
    background: linear-gradient(135deg, #EF4444, #DC2626);
}
.edu-detail-info h1 {
    font-size: 28px;
    font-weight: 700;
    color: #1F2937;
    margin: 0 0 16px;
    line-height: 1.3;
}
.edu-detail-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 16px;
    margin-bottom: 16px;
}
.edu-meta-item {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: #F3F4F6;
    border-radius: 8px;
    font-size: 13px;
    color: #4B5563;
}
.edu-meta-item i {
    color: #6B7280;
}
.edu-detail-tags {
    display: flex;
    gap: 10px;
    margin-bottom: 16px;
}
.edu-tag {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 6px 14px;
    background: #F8FAFC;
    border: 1px solid #E5E7EB;
    border-radius: 8px;
    font-size: 13px;
    color: #4B5563;
}
.edu-tag i {
    color: #6B7280;
}
.edu-detail-desc {
    color: #6B7280;
    line-height: 1.8;
    font-size: 14px;
    background: #F8FAFC;
    padding: 16px;
    border-radius: 10px;
    border-left: 3px solid #4F46E5;
    margin-bottom: 20px;
}
.edu-detail-actions {
    display: flex;
    gap: 12px;
    flex-wrap: wrap;
    align-items: center;
}
.edu-progress-box {
    width: 100%;
    margin-bottom: 12px;
}
.edu-progress-header {
    display: flex;
    justify-content: space-between;
    margin-bottom: 8px;
    font-size: 13px;
    color: #6B7280;
}
.edu-progress-header strong {
    color: #1F2937;
}
.edu-progress-bar {
    height: 8px;
    background: #E5E7EB;
    border-radius: 10px;
    overflow: hidden;
}
.edu-progress-fill {
    height: 100%;
    background: linear-gradient(90deg, #10B981, #34D399);
    border-radius: 10px;
    transition: width 0.5s ease;
}
.edu-btn {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    padding: 12px 24px;
    border-radius: 10px;
    font-size: 14px;
    font-weight: 600;
    text-decoration: none;
    cursor: pointer;
    border: none;
    transition: all 0.3s ease;
}
.edu-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 6px 20px rgba(0,0,0,0.15);
}
.edu-btn.primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.edu-btn.success {
    background: linear-gradient(135deg, #10B981, #059669);
    color: white;
}
.edu-btn.info {
    background: linear-gradient(135deg, #06B6D4, #0891B2);
    color: white;
}
.edu-btn.warning {
    background: linear-gradient(135deg, #F59E0B, #D97706);
    color: white;
}
.edu-btn.disabled {
    background: #F3F4F6;
    color: #9CA3AF;
    cursor: not-allowed;
}
.edu-btn.large {
    padding: 14px 32px;
    font-size: 16px;
}

/* 课程内容区 */
.edu-detail-content {
    background: #F8FAFC;
    padding: 40px 0 60px;
}
.edu-detail-main {
    max-width: 900px;
}
.edu-content-card {
    background: white;
    border-radius: 16px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    margin-bottom: 24px;
    overflow: hidden;
}
.edu-content-header {
    padding: 20px 24px;
    border-bottom: 2px solid #F1F5F9;
}
.edu-content-header h3 {
    margin: 0;
    font-size: 18px;
    font-weight: 700;
    color: #1F2937;
    display: flex;
    align-items: center;
    gap: 10px;
}
.edu-content-header h3 i {
    color: #4F46E5;
}
.edu-content-body {
    padding: 20px 24px;
}

/* 章节列表 */
.edu-chapter-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px;
    border-radius: 12px;
    margin-bottom: 12px;
    transition: all 0.3s ease;
}
.edu-chapter-item.completed {
    background: #F0FDF4;
    border: 1px solid #BBF7D0;
}
.edu-chapter-item.unlocked {
    background: white;
    border: 1px solid #E5E7EB;
}
.edu-chapter-item.unlocked:hover {
    border-color: #C7D2FE;
    box-shadow: 0 2px 8px rgba(0,0,0,0.05);
}
.edu-chapter-item.locked {
    background: #F9FAFB;
    border: 1px solid #F3F4F6;
}
.edu-chapter-info {
    display: flex;
    align-items: center;
    gap: 14px;
    flex: 1;
}
.edu-chapter-icon {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 18px;
    flex-shrink: 0;
}
.edu-chapter-item.completed .edu-chapter-icon {
    background: #D1FAE5;
    color: #059669;
}
.edu-chapter-item.unlocked .edu-chapter-icon {
    background: #EEF2FF;
    color: #4F46E5;
}
.edu-chapter-item.locked .edu-chapter-icon {
    background: #F3F4F6;
    color: #9CA3AF;
}
.edu-chapter-icon.exam {
    background: #FFF7ED;
    color: #F59E0B;
}
.edu-chapter-text h5 {
    margin: 0 0 4px;
    font-size: 15px;
    font-weight: 600;
    color: #1F2937;
}
.edu-chapter-item.locked .edu-chapter-text h5 {
    color: #9CA3AF;
}
.edu-chapter-text p {
    margin: 0;
    font-size: 13px;
    color: #6B7280;
}
.edu-chapter-actions {
    display: flex;
    gap: 8px;
    align-items: center;
}
.edu-chapter-btn {
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    text-decoration: none;
    border: none;
    cursor: pointer;
    transition: all 0.3s ease;
    display: inline-flex;
    align-items: center;
    gap: 6px;
}
.edu-chapter-btn.play {
    background: #D1FAE5;
    color: #059669;
}
.edu-chapter-btn.play:hover {
    background: #A7F3D0;
}
.edu-chapter-btn.complete {
    background: #EEF2FF;
    color: #4F46E5;
}
.edu-chapter-btn.complete:hover {
    background: #E0E7FF;
}
.edu-chapter-btn.info {
    background: #E0F2FE;
    color: #0284C7;
}
.edu-chapter-btn.info:hover {
    background: #BAE6FD;
}
.edu-chapter-btn.primary {
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
}
.edu-chapter-btn.primary:hover {
    box-shadow: 0 4px 12px rgba(79,70,229,0.3);
}
.edu-chapter-status {
    font-size: 12px;
    color: #9CA3AF;
}
.edu-chapter-status.done {
    color: #059669;
    font-weight: 600;
}
.edu-exam-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 16px;
    background: #FFFBEB;
    border: 1px solid #FDE68A;
    border-radius: 12px;
    margin-top: 12px;
}

/* 课程介绍 */
.edu-course-intro {
    line-height: 1.9;
    color: #4B5563;
    font-size: 14px;
}

/* 相关课程 */
.edu-related-grid {
    display: grid;
    grid-template-columns: repeat(4, 1fr);
    gap: 16px;
}
.edu-related-card {
    background: #F8FAFC;
    border-radius: 12px;
    overflow: hidden;
    text-decoration: none;
    transition: all 0.3s ease;
}
.edu-related-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 8px 20px rgba(0,0,0,0.1);
}
.edu-related-cover {
    height: 120px;
    overflow: hidden;
}
.edu-related-cover img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}
.edu-related-cover-fallback {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, #EEF2FF, #E0E7FF);
    display: flex;
    align-items: center;
    justify-content: center;
    color: #4F46E5;
    font-size: 32px;
}
.edu-related-info {
    padding: 12px;
}
.edu-related-info h5 {
    margin: 0 0 6px;
    font-size: 14px;
    font-weight: 600;
    color: #1F2937;
    overflow: hidden;
    text-overflow: ellipsis;
    white-space: nowrap;
}
.edu-related-meta {
    display: flex;
    gap: 12px;
    font-size: 12px;
    color: #6B7280;
}
.edu-related-meta i {
    margin-right: 4px;
}

/* 视频模态框 */
.edu-video-empty {
    background: #111827;
    text-align: center;
    padding: 100px 20px;
    color: white;
}
.edu-video-empty i {
    font-size: 60px;
    color: #4F46E5;
    margin-bottom: 20px;
    display: block;
}
.edu-video-empty p {
    font-size: 16px;
    color: #9CA3AF;
}

/* 响应式 */
@media (max-width: 992px) {
    .edu-detail-layout { grid-template-columns: 1fr; }
    .edu-related-grid { grid-template-columns: repeat(2, 1fr); }
}
@media (max-width: 768px) {
    .edu-detail-cover img { height: 220px; }
    .edu-detail-cover-fallback { height: 220px; }
    .edu-detail-info h1 { font-size: 22px; }
    .edu-chapter-item { flex-direction: column; align-items: flex-start; gap: 12px; }
    .edu-chapter-actions { width: 100%; justify-content: flex-end; }
    .edu-related-grid { grid-template-columns: 1fr; }
}
@media (max-width: 576px) {
    .edu-detail-meta { flex-direction: column; gap: 8px; }
    .edu-detail-actions { flex-direction: column; }
    .edu-detail-actions .edu-btn { width: 100%; justify-content: center; }
}

/* ================================================================
   ===== 登录页面 UI =====
   ================================================================ */

.edu-login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, #1E3A5F 0%, #0D2137 50%, #1A365D 100%);
    position: relative;
    overflow: hidden;
    padding: 40px 20px;
}
.edu-login-bg {
    position: absolute;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: url('data:image/svg+xml,<svg xmlns="http://www.w3.org/2000/svg" viewBox="0 0 100 100"><circle cx="50" cy="50" r="40" fill="none" stroke="rgba(255,255,255,0.03)" stroke-width="0.5"/></svg>') repeat;
    background-size: 80px;
}
.edu-login-container {
    position: relative;
    z-index: 1;
    display: flex;
    gap: 60px;
    align-items: center;
    max-width: 900px;
    width: 100%;
}
.edu-login-card {
    background: white;
    border-radius: 20px;
    padding: 40px;
    width: 420px;
    box-shadow: 0 25px 60px rgba(0,0,0,0.3);
}
.edu-login-header {
    text-align: center;
    margin-bottom: 32px;
}
.edu-login-logo {
    width: 80px;
    height: 80px;
    margin: 0 auto 20px;
    border-radius: 50%;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    display: flex;
    align-items: center;
    justify-content: center;
    color: white;
    font-size: 36px;
    box-shadow: 0 12px 30px rgba(79,70,229,0.35);
}
.edu-login-header h2 {
    margin: 0 0 8px;
    font-size: 24px;
    font-weight: 700;
    color: #1F2937;
}
.edu-login-header p {
    margin: 0;
    color: #6B7280;
    font-size: 14px;
}
.edu-form-group {
    margin-bottom: 20px;
}
.edu-form-group label {
    display: block;
    margin-bottom: 8px;
    font-size: 14px;
    font-weight: 600;
    color: #374151;
}
.edu-input-wrapper {
    position: relative;
}
.edu-input-wrapper i {
    position: absolute;
    left: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #9CA3AF;
    font-size: 16px;
}
.edu-input-wrapper input {
    width: 100%;
    padding: 14px 16px 14px 48px;
    border: 2px solid #E5E7EB;
    border-radius: 12px;
    font-size: 15px;
    transition: all 0.3s ease;
}
.edu-input-wrapper input:focus {
    border-color: #4F46E5;
    outline: none;
    box-shadow: 0 0 0 3px rgba(79,70,229,0.1);
}
.edu-input-wrapper #togglePassword {
    position: absolute;
    right: 16px;
    top: 50%;
    transform: translateY(-50%);
    color: #9CA3AF;
    cursor: pointer;
}
.edu-form-options {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 24px;
}
.edu-checkbox {
    display: flex;
    align-items: center;
    gap: 8px;
    font-size: 14px;
    color: #6B7280;
    cursor: pointer;
}
.edu-checkbox input {
    width: 16px;
    height: 16px;
    accent-color: #4F46E5;
}
.edu-forgot {
    font-size: 14px;
    color: #4F46E5;
    text-decoration: none;
}
.edu-forgot:hover {
    color: #3730A3;
}
.edu-submit-btn {
    width: 100%;
    padding: 14px;
    background: linear-gradient(135deg, #4F46E5, #7C3AED);
    color: white;
    border: none;
    border-radius: 12px;
    font-size: 16px;
    font-weight: 600;
    cursor: pointer;
    transition: all 0.3s ease;
}
.edu-submit-btn:hover {
    transform: translateY(-2px);
    box-shadow: 0 8px 25px rgba(79,70,229,0.4);
}
.edu-submit-btn:disabled {
    opacity: 0.7;
    cursor: not-allowed;
}
.edu-login-footer {
    text-align: center;
    margin-top: 24px;
    padding-top: 20px;
    border-top: 1px solid #E5E7EB;
    font-size: 14px;
    color: #6B7280;
}
.edu-login-footer a {
    color: #4F46E5;
    font-weight: 600;
    text-decoration: none;
    margin-left: 6px;
}
.edu-login-footer a:hover {
    color: #3730A3;
}
.edu-back-home {
    display: block;
    text-align: center;
    margin-top: 16px;
    font-size: 13px;
    color: #9CA3AF;
    text-decoration: none;
}
.edu-back-home:hover {
    color: #6B7280;
}
.edu-login-features {
    flex: 1;
    color: white;
}
.edu-login-features h3 {
    font-size: 28px;
    font-weight: 700;
    margin-bottom: 40px;
}
.edu-feature-item {
    display: flex;
    gap: 16px;
    margin-bottom: 30px;
}
.edu-feature-item i {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    background: rgba(255,255,255,0.1);
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 22px;
    flex-shrink: 0;
}
.edu-feature-item h4 {
    margin: 0 0 4px;
    font-size: 16px;
    font-weight: 600;
}
.edu-feature-item p {
    margin: 0;
    font-size: 14px;
    opacity: 0.8;
}
@media (max-width: 992px) {
    .edu-login-features { display: none; }
    .edu-login-card { width: 100%; max-width: 420px; }
}
@media (max-width: 576px) {
    .edu-login-card { padding: 30px 24px; }
    .edu-login-logo { width: 64px; height: 64px; font-size: 28px; }
}