:root {
    --primary: var(--gwr-primary, #166534);
    --primary-light: var(--gwr-primary-light, #22c55e);
    --primary-dark: var(--gwr-primary-dark, #052e16);
    --accent: var(--gwr-gold, #84cc16);
    --accent-hover: var(--gwr-gold-dark, #4d7c0f);
    --success: #059669;
    --danger: #FF0000;
    --warning: var(--gwr-gold, #84cc16);
    --info: #2563EB;
    --bg: #F9FAFB;
    --card-bg: #ffffff;
    --text: #1F2937;
    --text-light: #6B7280;
    --border: #E5E7EB;
    --shadow: 0 2px 12px rgba(0,0,0,0.08);
    --shadow-lg: 0 8px 30px rgba(0,0,0,0.12);
    --radius: 10px;
    --radius-sm: 6px;
    --transition: all 0.3s ease;
}

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    min-height: 100vh;
}

a {
    color: var(--primary);
    text-decoration: none;
    transition: var(--transition);
}

a:hover {
    color: var(--accent);
}

/* Navbar */
.navbar {
    background: linear-gradient(135deg, var(--primary-dark), var(--primary));
    padding: 0 2rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    height: 65px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.15);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar-brand {
    display: flex;
    align-items: center;
    gap: 12px;
    color: #fff;
    font-size: 1.2rem;
    font-weight: 700;
}

.navbar-brand .brand-icon {
    width: 40px;
    height: 40px;
    background: var(--accent);
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
}

.navbar-nav {
    display: flex;
    list-style: none;
    gap: 6px;
    align-items: center;
}

.navbar-search {
    flex: 1;
    max-width: 520px;
    min-width: 0;
    margin: 0 1.5rem;
    display: flex;
    align-items: center;
    background: #fff;
    border-radius: 999px;
    overflow: hidden;
    box-shadow: 0 2px 8px rgba(0,0,0,0.18);
}

.navbar-search input {
    flex: 1;
    min-width: 0;
    border: none;
    outline: none;
    padding: 10px 18px;
    font-size: 0.92rem;
    background: transparent;
    color: var(--text);
}

.navbar-search button {
    border: none;
    background: #e5e7eb;
    color: #374151;
    padding: 10px 18px;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.navbar-search button:hover {
    background: var(--primary);
    color: #fff;
}

.navbar-nav a {
    color: rgba(255,255,255,0.85);
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    font-size: 0.92rem;
    font-weight: 500;
    transition: var(--transition);
}

.navbar-nav a:hover,
.navbar-nav a.active {
    background: rgba(255,255,255,0.15);
    color: #fff;
}

.navbar-nav .nav-user {
    color: #fff;
    background: var(--accent);
    padding: 6px 14px;
    border-radius: 20px;
    font-weight: 600;
    font-size: 0.85rem;
}

.navbar-nav .nav-user:hover {
    background: var(--accent-hover);
    color: #fff;
}

/* Layout */
.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 2rem;
}

.page-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 2rem;
    flex-wrap: wrap;
    gap: 1rem;
}

.page-header h1 {
    font-size: 1.75rem;
    color: var(--primary-dark);
    font-weight: 700;
}

/* Cards */
.card {
    background: var(--card-bg);
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    padding: 1.5rem;
    margin-bottom: 1.5rem;
    transition: var(--transition);
    border: 1px solid var(--border);
}

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

.card-header {
    border-bottom: 1px solid var(--border);
    padding-bottom: 1rem;
    margin-bottom: 1rem;
}

.card-header h3 {
    font-size: 1.1rem;
    color: var(--primary);
    font-weight: 600;
}

/* Stats Grid */
.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.5rem;
    box-shadow: var(--shadow);
    border-left: 4px solid var(--primary);
    transition: var(--transition);
}

.stat-card:hover {
    transform: translateY(-3px);
    box-shadow: var(--shadow-lg);
}

.stat-card.accent { border-left-color: var(--accent); }
.stat-card.success { border-left-color: var(--success); }
.stat-card.info { border-left-color: var(--info); }
.stat-card.warning { border-left-color: var(--warning); }

.stat-card .stat-number {
    font-size: 2rem;
    font-weight: 700;
    color: var(--primary-dark);
    line-height: 1;
}

.stat-card .stat-label {
    font-size: 0.85rem;
    color: var(--text-light);
    margin-top: 6px;
    text-transform: uppercase;
    letter-spacing: 0.5px;
    font-weight: 500;
}

/* Tables */
.table-responsive {
    overflow-x: auto;
    border-radius: var(--radius);
    border: 1px solid var(--border);
}

table {
    width: 100%;
    border-collapse: collapse;
}

table th,
table td {
    padding: 12px 16px;
    text-align: left;
    border-bottom: 1px solid var(--border);
    font-size: 0.92rem;
}

table th {
    background: var(--primary);
    color: #fff;
    font-weight: 600;
    white-space: nowrap;
}

table tbody tr:hover {
    background: #f8f9fa;
}

table td:last-child {
    white-space: nowrap;
}

/* Buttons */
.btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 10px 20px;
    border: none;
    border-radius: var(--radius-sm);
    font-size: 0.9rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    text-decoration: none;
    line-height: 1.4;
}

.btn-primary {
    background: var(--primary);
    color: #fff;
}
.btn-primary:hover {
    background: var(--primary-light);
    color: #fff;
    transform: translateY(-1px);
}

.btn-accent {
    background: var(--accent);
    color: #fff;
}
.btn-accent:hover {
    background: var(--accent-hover);
    color: #fff;
}

.btn-success {
    background: var(--success);
    color: #fff;
}
.btn-success:hover {
    background: #219a52;
    color: #fff;
}

.btn-danger {
    background: var(--danger);
    color: #fff;
}
.btn-danger:hover {
    background: #c0392b;
    color: #fff;
}

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

.btn-sm {
    padding: 6px 12px;
    font-size: 0.82rem;
}

.btn-group {
    display: flex;
    gap: 6px;
    flex-wrap: nowrap;
    white-space: nowrap;
}

/* Forms */
.form-group {
    margin-bottom: 1.25rem;
}

.form-group label {
    display: block;
    margin-bottom: 6px;
    font-weight: 600;
    font-size: 0.9rem;
    color: var(--primary-dark);
}

.form-group input,
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px 14px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.95rem;
    transition: var(--transition);
    font-family: inherit;
}

.form-group input:focus,
.form-group select:focus,
.form-group textarea:focus {
    outline: none;
    border-color: var(--primary);
    box-shadow: 0 0 0 3px rgba(26,58,92,0.1);
}

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

.form-row {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 1rem;
}

/* Alerts */
.alert {
    padding: 14px 18px;
    border-radius: var(--radius-sm);
    margin-bottom: 1.5rem;
    font-size: 0.92rem;
    font-weight: 500;
}

.alert-success {
    background: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.alert-error {
    background: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.alert-info {
    background: #d1ecf1;
    color: #0c5460;
    border: 1px solid #bee5eb;
}

/* Badges */
.badge {
    display: inline-block;
    padding: 4px 10px;
    border-radius: 20px;
    font-size: 0.75rem;
    font-weight: 600;
    text-transform: uppercase;
    letter-spacing: 0.3px;
}

.badge-primary { background: var(--primary); color: #fff; }
.badge-accent { background: var(--accent); color: #fff; }
.badge-success { background: var(--success); color: #fff; }
.badge-info { background: var(--info); color: #fff; }
.badge-warning { background: var(--warning); color: #fff; }
.badge-danger { background: var(--danger); color: #fff; }

/* Book Grid */
.book-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
    gap: 1.5rem;
}

.book-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
}

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

.book-card .book-cover {
    width: 100%;
    height: 200px;
    object-fit: cover;
    background: linear-gradient(135deg, var(--primary-light), var(--primary-dark));
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 3rem;
}

.book-card .book-cover img {
    width: 100%;
    height: 200px;
    object-fit: cover;
}

.book-card .book-info {
    padding: 1rem 1.25rem;
}

.book-card .book-title {
    font-size: 1rem;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: 6px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.book-card .book-meta {
    font-size: 0.82rem;
    color: var(--text-light);
    margin-bottom: 10px;
}

.book-card .book-stats {
    display: flex;
    gap: 12px;
    font-size: 0.8rem;
    color: var(--text-light);
}

.book-card .book-actions {
    padding: 0.75rem 1.25rem;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

/* Login Page */
.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--primary-dark) 0%, var(--primary) 50%, var(--primary-light) 100%);
    padding: 2rem;
}

.login-card {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow-lg);
    width: 100%;
    max-width: 440px;
    padding: 2.5rem;
}

.login-card .brand {
    text-align: center;
    margin-bottom: 2rem;
}

.login-card .brand h1 {
    font-size: 1.5rem;
    color: var(--primary-dark);
    margin-top: 0.75rem;
}

.login-card .brand .college-icon {
    width: 80px;
    height: 80px;
    background: linear-gradient(135deg, var(--primary), var(--accent));
    border-radius: 50%;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    font-size: 2.5rem;
    color: #fff;
}

.login-card .brand p {
    color: var(--text-light);
    font-size: 0.85rem;
    margin-top: 4px;
}

.login-card .form-group {
    margin-bottom: 1.25rem;
}

.login-card .btn-primary {
    width: 100%;
    padding: 12px;
    font-size: 1rem;
    margin-top: 0.5rem;
}

.login-card .login-footer {
    text-align: center;
    margin-top: 1.5rem;
    font-size: 0.88rem;
    color: var(--text-light);
}

/* Modal */
.modal-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.5);
    z-index: 2000;
    align-items: center;
    justify-content: center;
}

.modal-overlay.active {
    display: flex;
}

.modal {
    background: #fff;
    border-radius: var(--radius);
    width: 90%;
    max-width: 500px;
    max-height: 90vh;
    overflow-y: auto;
    box-shadow: var(--shadow-lg);
}

.modal-header {
    padding: 1.25rem 1.5rem;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.modal-header h3 {
    font-size: 1.1rem;
    color: var(--primary-dark);
}

.modal-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--text-light);
    padding: 0;
    line-height: 1;
}

.modal-body {
    padding: 1.5rem;
}

.modal-footer {
    padding: 1rem 1.5rem;
    border-top: 1px solid var(--border);
    display: flex;
    justify-content: flex-end;
    gap: 10px;
}

/* Comments */
.comments-section {
    margin-top: 2rem;
}

.comment {
    display: flex;
    gap: 12px;
    padding: 1rem 0;
    border-bottom: 1px solid var(--border);
}

.comment:last-child {
    border-bottom: none;
}

.comment-avatar {
    width: 40px;
    height: 40px;
    border-radius: 50%;
    background: var(--primary);
    color: #fff;
    display: flex;
    align-items: center;
    justify-content: center;
    font-weight: 700;
    font-size: 0.9rem;
    flex-shrink: 0;
}

.comment-body {
    flex: 1;
}

.comment-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 4px;
}

.comment-author {
    font-weight: 600;
    font-size: 0.92rem;
    color: var(--primary-dark);
}

.comment-time {
    font-size: 0.8rem;
    color: var(--text-light);
}

.comment-text {
    font-size: 0.92rem;
    line-height: 1.5;
    color: var(--text);
}

.comment-form {
    margin-top: 1.5rem;
}

/* Breadcrumb */
.breadcrumb {
    display: flex;
    gap: 8px;
    align-items: center;
    margin-bottom: 1.5rem;
    font-size: 0.88rem;
    color: var(--text-light);
}

.breadcrumb a {
    color: var(--primary);
}

.breadcrumb span {
    color: var(--text-light);
}

/* Sidebar filter */
.content-layout {
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 2rem;
    align-items: start;
}

.sidebar {
    background: var(--card-bg);
    border-radius: var(--radius);
    padding: 1.25rem;
    box-shadow: var(--shadow);
    border: 1px solid var(--border);
    position: sticky;
    top: 85px;
}

.sidebar h3 {
    font-size: 1rem;
    color: var(--primary-dark);
    margin-bottom: 1rem;
    padding-bottom: 0.5rem;
    border-bottom: 2px solid var(--accent);
}

.sidebar .filter-group {
    margin-bottom: 1.25rem;
}

.sidebar .filter-group label {
    display: block;
    font-weight: 600;
    font-size: 0.85rem;
    margin-bottom: 6px;
    color: var(--text);
}

.sidebar .filter-group select {
    width: 100%;
    padding: 8px 10px;
    border: 2px solid var(--border);
    border-radius: var(--radius-sm);
    font-size: 0.88rem;
    background: #fff;
}

.sidebar .filter-group select:focus {
    outline: none;
    border-color: var(--primary);
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 3rem 1rem;
    color: var(--text-light);
}

.empty-state .empty-icon {
    font-size: 4rem;
    margin-bottom: 1rem;
    opacity: 0.5;
}

.empty-state h3 {
    color: var(--text);
    margin-bottom: 0.5rem;
}

/* Book Detail */
.book-detail-header {
    display: grid;
    grid-template-columns: 260px 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.book-detail-media {
    display: flex;
    flex-direction: column;
    gap: 1.5rem;
    align-items: stretch;
}

.book-engagement {
    margin-top: 0;
}

.book-detail-cover {
    width: 260px;
    height: 200px;
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
}

.book-detail-cover img {
    width: 100%;
    height: 100%;
    object-fit: contain;
    background: #fff;
}

.book-detail-cover .no-cover {
    width: 100%;
    height: 100%;
    background: linear-gradient(135deg, var(--primary-light), var(--primary-dark));
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 4rem;
}

.book-detail-info h1 {
    font-size: 1.6rem;
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

.book-detail-meta {
    display: flex;
    flex-wrap: wrap;
    gap: 12px;
    margin: 1rem 0;
}

.book-detail-meta .meta-item {
    display: flex;
    align-items: center;
    gap: 6px;
    font-size: 0.9rem;
    color: var(--text-light);
}

.desc-wrap {
    position: relative;
    margin: 1.25rem 0;
}

.book-detail-description {
    margin: 0;
    line-height: 1.7;
    color: var(--text);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.book-detail-description.expanded {
    -webkit-line-clamp: unset;
    overflow: visible;
}

.desc-toggle {
    position: absolute;
    bottom: 2px;
    right: 0;
    padding: 2px 0 2px 24px;
    border: none;
    background: linear-gradient(90deg, transparent, var(--bg) 60%, var(--bg));
    color: var(--primary);
    font-size: 0.85rem;
    font-weight: 700;
    cursor: pointer;
    transition: var(--transition);
    z-index: 1;
}

.desc-toggle:hover {
    color: var(--primary-dark);
    text-decoration: underline;
}

.book-detail-description.expanded ~ .desc-toggle {
    position: static;
    display: block;
    margin-top: 6px;
    padding: 0;
    background: none;
}

.book-reader {
    background: #fff;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
    overflow: hidden;
    margin-bottom: 2rem;
    border: 1px solid var(--border);
}

.book-reader iframe {
    width: 100%;
    height: 600px;
    border: none;
    display: block;
}

.reader-toolbar {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 8px 14px;
    border-bottom: 1px solid var(--border);
    background: #f9fafb;
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text);
}

.reader-toolbar .reader-fullscreen-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 16px;
    border: none;
    border-radius: 999px;
    background: linear-gradient(135deg, #22d3ee, #3b82f6, #8b5cf6, #06b6d4);
    background-size: 300% 300%;
    animation: fsGradient 4s ease infinite;
    cursor: pointer;
    font-size: 0.9rem;
    font-weight: 800;
    letter-spacing: 0.2px;
    color: #fff;
    text-shadow: 0 1px 3px rgba(0,0,0,0.25);
    box-shadow: 0 4px 14px rgba(59, 130, 246, 0.35);
    transition: transform 0.2s ease;
}

@keyframes fsGradient {
    0% { background-position: 0% 50%; }
    50% { background-position: 100% 50%; }
    100% { background-position: 0% 50%; }
}

.reader-toolbar .reader-fullscreen-btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 6px 18px rgba(59, 130, 246, 0.5);
}

.book-reader:fullscreen {
    width: 100vw;
    height: 100vh;
    display: flex;
    flex-direction: column;
    border: none;
    border-radius: 0;
}

.book-reader:fullscreen .reader-toolbar {
    flex-shrink: 0;
}

.book-reader:fullscreen iframe {
    height: 100%;
    flex: 1;
}

.book-reader .reader-placeholder {
    padding: 3rem;
    text-align: center;
    color: var(--text-light);
}

/* Book Detail Layout (main + related sidebar) */
.book-detail-layout {
    display: grid;
    grid-template-columns: minmax(0, 1fr) 320px;
    gap: 2rem;
    align-items: start;
}

.book-actions-row {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.book-engagement {
    display: flex;
    flex-wrap: nowrap;
    gap: 6px;
    margin-top: 0;
}

.engagement-btn {
    display: inline-flex;
    align-items: center;
    gap: 6px;
    padding: 8px 14px;
    border: 1px solid var(--border);
    border-radius: 999px;
    background: var(--card-bg);
    color: var(--text);
    font-size: 0.85rem;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
}

.engagement-btn:hover {
    border-color: var(--primary);
    color: var(--primary);
}

.engagement-btn svg {
    fill: none;
    stroke: currentColor;
}

.engagement-btn svg circle,
.engagement-btn svg line {
    stroke: currentColor;
}

.engagement-btn.active {
    background: var(--primary);
    color: #fff;
    border-color: var(--primary);
}

.engagement-btn.active svg {
    fill: currentColor;
    stroke: currentColor;
}

.engagement-btn {
    flex: 1;
    justify-content: center;
    min-width: 0;
    overflow: hidden;
    white-space: nowrap;
    padding: 8px 4px;
    font-size: 0.8rem;
}

.engagement-btn svg {
    flex-shrink: 0;
}

.engagement-btn span {
    flex-shrink: 0;
}

.book-related {
    position: sticky;
    top: 85px;
}

.book-related h3 {
    font-size: 1rem;
    color: var(--primary-dark);
    margin-bottom: 1rem;
    border-bottom: 2px solid var(--primary);
    padding-bottom: 8px;
}

.related-card {
    display: flex;
    gap: 10px;
    padding: 8px;
    border: 1px solid var(--border);
    border-radius: 8px;
    margin-bottom: 10px;
    background: var(--card-bg);
    text-decoration: none;
    color: inherit;
    transition: var(--transition);
    align-items: flex-start;
}

.related-card:hover {
    border-color: var(--primary);
    box-shadow: var(--shadow);
}

.related-thumb {
    width: 76px;
    height: 58px;
    flex-shrink: 0;
    background: #f3f4f6;
    border-radius: 6px;
    overflow: hidden;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 1.4rem;
}

.related-thumb img {
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.related-info {
    display: flex;
    flex-direction: column;
    min-width: 0;
}

.related-title {
    font-size: 0.85rem;
    font-weight: 600;
    line-height: 1.35;
    color: var(--text);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.related-sub {
    font-size: 0.75rem;
    color: var(--text-light);
    margin-top: 2px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

/* Video Detail */
.video-detail-header {
    display: grid;
    grid-template-columns: 1fr 1fr;
    gap: 2rem;
    margin-bottom: 2rem;
}

.video-player-wrapper {
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow-lg);
    background: #000;
}

.video-player-wrapper video {
    width: 100%;
    max-height: 450px;
    display: block;
}

.video-detail-info h1 {
    font-size: 1.6rem;
    color: var(--primary-dark);
    margin-bottom: 0.5rem;
}

/* Video Grid */
.video-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.video-card {
    background: var(--card-bg);
    border-radius: var(--radius);
    overflow: hidden;
    box-shadow: var(--shadow);
    transition: var(--transition);
    border: 1px solid var(--border);
    text-decoration: none;
    color: inherit;
    display: block;
}

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

.video-card:hover .video-play-btn {
    transform: translate(-50%, -50%) scale(1.15);
    background: var(--accent);
}

.video-card:hover .video-play-overlay {
    opacity: 1;
}

.video-thumb {
    position: relative;
    width: 100%;
    padding-top: 56.25%;
    overflow: hidden;
    background: linear-gradient(135deg, var(--primary-light), var(--primary-dark));
}

.video-thumb img {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    object-fit: cover;
}

.video-thumb-placeholder {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 3rem;
}

.video-play-overlay {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0,0,0,0.3);
    display: flex;
    align-items: center;
    justify-content: center;
    opacity: 0;
    transition: opacity 0.3s ease;
}

.video-card:hover .video-play-overlay {
    opacity: 1;
}

.video-play-btn {
    position: absolute;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%) scale(1);
    width: 60px;
    height: 60px;
    background: rgba(230, 126, 34, 0.9);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    color: #fff;
    font-size: 1.5rem;
    line-height: 1;
    transition: all 0.3s ease;
    box-shadow: 0 4px 15px rgba(0,0,0,0.3);
}

.video-badge-yt {
    position: absolute;
    bottom: 8px;
    right: 8px;
    background: rgba(255,0,0,0.85);
    color: #fff;
    font-size: 0.7rem;
    font-weight: 700;
    padding: 3px 8px;
    border-radius: 4px;
    letter-spacing: 0.3px;
}

.video-card-info {
    padding: 0.85rem 1rem 1rem;
}

.video-card-title {
    font-size: 0.95rem;
    font-weight: 700;
    color: var(--primary-dark);
    margin-bottom: 4px;
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
    line-height: 1.3;
}

.video-card-meta {
    font-size: 0.8rem;
    color: var(--text-light);
    margin-bottom: 6px;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.video-card-stats {
    display: flex;
    gap: 10px;
    font-size: 0.78rem;
    color: var(--text-light);
    align-items: center;
}

/* Footer */
.footer {
    background: var(--primary-dark);
    color: rgba(255,255,255,0.7);
    text-align: center;
    padding: 1.5rem;
    margin-top: 3rem;
    font-size: 0.85rem;
}

.footer strong {
    color: #fff;
}

/* Responsive */
@media (max-width: 768px) {
    .navbar {
        padding: 0 1rem;
        flex-wrap: wrap;
        height: auto;
        padding-top: 10px;
        padding-bottom: 10px;
    }

    .navbar-nav {
        flex-wrap: wrap;
        gap: 4px;
        order: 2;
    }

    .navbar-search {
        order: 3;
        flex: 1 1 100%;
        max-width: 100%;
        margin: 10px 0 0;
    }

    .container {
        padding: 1rem;
    }

    .content-layout {
        grid-template-columns: 1fr;
    }

    .sidebar {
        position: static;
    }

    .book-detail-header {
        grid-template-columns: 1fr;
        text-align: center;
    }

    .book-engagement {
        justify-content: center;
    }

    .book-detail-layout {
        grid-template-columns: 1fr;
    }

    .book-related {
        position: static;
    }

    .video-detail-header {
        grid-template-columns: 1fr;
    }

    .video-grid {
        grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
    }

    .book-detail-cover {
        margin: 0 auto;
    }

    .form-row {
        grid-template-columns: 1fr;
    }

    .page-header {
        flex-direction: column;
        align-items: flex-start;
    }
}

/* Scrollbar */
::-webkit-scrollbar {
    width: 8px;
}
::-webkit-scrollbar-track {
    background: var(--bg);
}
::-webkit-scrollbar-thumb {
    background: var(--primary-light);
    border-radius: 4px;
}
::-webkit-scrollbar-thumb:hover {
    background: var(--primary);
}