:root {
    /* Светлая тема */
    --primary-color: #2c3e50;
    --secondary-color: #3498db;
    --accent-color: #e74c3c;
    --success-color: #27ae60;
    --warning-color: #f39c12;
    --danger-color: #c0392b;
    
    --bg-color: #ffffff;
    --bg-secondary: #f8f9fa;
    --text-color: #333333;
    --text-secondary: #666666;
    --border-color: #dee2e6;
    
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.1);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.15);
    
    --radius: 8px;
    --radius-sm: 4px;
    
    --transition: all 0.3s ease;
}

.dark-theme {
    /* Тёмная тема */
    --primary-color: #3498db;
    --secondary-color: #2c3e50;
    --accent-color: #e74c3c;
    
    --bg-color: #1a1a1a;
    --bg-secondary: #2d2d2d;
    --text-color: #f0f0f0;
    --text-secondary: #b0b0b0;
    --border-color: #404040;
    
    --shadow: 0 2px 8px rgba(0, 0, 0, 0.3);
    --shadow-lg: 0 4px 16px rgba(0, 0, 0, 0.4);
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background-color: var(--bg-color);
    color: var(--text-color);
    line-height: 1.6;
    transition: var(--transition);
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 0 20px;
}

/* Header */
.header {
    background: var(--primary-color);
    color: white;
    padding: 1rem 0;
    box-shadow: var(--shadow);
}

.header-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.back-link {
    color: white;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 8px;
    padding: 8px 16px;
    border-radius: var(--radius-sm);
    background: rgba(255, 255, 255, 0.1);
    transition: var(--transition);
}

.back-link:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: translateX(-2px);
}

.theme-toggle {
    background: rgba(255, 255, 255, 0.1);
    border: none;
    color: white;
    width: 40px;
    height: 40px;
    border-radius: 50%;
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.theme-toggle:hover {
    background: rgba(255, 255, 255, 0.2);
    transform: rotate(30deg);
}

/* Main Content */
.main-content {
    padding: 2rem 0;
    min-height: calc(100vh - 140px);
}

.catalog-header {
    text-align: center;
    margin-bottom: 2rem;
}

.catalog-title {
    color: var(--primary-color);
    margin-bottom: 0.5rem;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 10px;
}

.catalog-subtitle {
    color: var(--text-secondary);
    font-size: 1.1rem;
}

/* Search Form */
.search-form {
    margin-bottom: 2rem;
}

.search-wrapper {
    display: flex;
    gap: 10px;
    position: relative;
}

.search-icon {
    position: absolute;
    left: 15px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-secondary);
}

.search-wrapper input {
    flex: 1;
    padding: 12px 45px 12px 45px;
    border: 2px solid var(--border-color);
    border-radius: var(--radius);
    font-size: 1rem;
    background: var(--bg-color);
    color: var(--text-color);
    transition: var(--transition);
}

.search-wrapper input:focus {
    outline: none;
    border-color: var(--secondary-color);
    box-shadow: 0 0 0 3px rgba(52, 152, 219, 0.1);
}

/* Buttons */
.btn {
    padding: 12px 24px;
    border: none;
    border-radius: var(--radius);
    font-size: 1rem;
    cursor: pointer;
    display: inline-flex;
    align-items: center;
    gap: 8px;
    transition: var(--transition);
    text-decoration: none;
}

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

.btn-primary:hover {
    background: #2980b9;
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-secondary);
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

.btn-secondary:hover {
    background: var(--border-color);
}

.btn-success {
    background: var(--success-color);
    color: white;
}

.btn-danger {
    background: var(--danger-color);
    color: white;
}

.btn-sm {
    padding: 6px 12px;
    font-size: 0.875rem;
}

/* Table */
.table-responsive {
    overflow-x: auto;
    margin-bottom: 2rem;
    border-radius: var(--radius);
    box-shadow: var(--shadow);
}

.book-table {
    width: 100%;
    border-collapse: collapse;
    background: var(--bg-color);
}

.book-table th {
    background: var(--bg-secondary);
    padding: 16px;
    text-align: left;
    font-weight: 600;
    border-bottom: 2px solid var(--border-color);
    position: sticky;
    top: 0;
    z-index: 10;
}

.book-table td {
    padding: 16px;
    border-bottom: 1px solid var(--border-color);
}

.book-table tr:hover {
    background: var(--bg-secondary);
}

/* Book Cover */
.book-cover-wrapper {
    width: 60px;
    height: 85px;
    display: flex;
    align-items: center;
    justify-content: center;
}

.book-cover {
    width: 100%;
    height: 100%;
    object-fit: cover;
    border-radius: 4px;
    box-shadow: var(--shadow);
}

.book-cover-placeholder {
    width: 100%;
    height: 100%;
    background: var(--bg-secondary);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 1.5rem;
}

/* Action Buttons */
.action-buttons {
    display: flex;
    gap: 8px;
}

.btn-action {
    width: 36px;
    height: 36px;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    transition: var(--transition);
}

.btn-view {
    background: var(--secondary-color);
    color: white;
}

.btn-edit {
    background: var(--warning-color);
    color: white;
}

.btn-delete {
    background: var(--danger-color);
    color: white;
}

.btn-external {
    background: var(--success-color);
    color: white;
}

.btn-action:hover {
    transform: scale(1.1);
}

/* Grid View */
.books-grid {
    display: none;
    grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
    gap: 20px;
    margin-bottom: 2rem;
}

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

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

.book-card-header {
    display: flex;
    gap: 15px;
    padding: 20px;
    background: var(--bg-secondary);
}

.book-card-cover {
    width: 80px;
    height: 110px;
    object-fit: cover;
    border-radius: 4px;
}

.book-card-cover-placeholder {
    width: 80px;
    height: 110px;
    background: var(--border-color);
    border-radius: 4px;
    display: flex;
    align-items: center;
    justify-content: center;
    color: var(--text-secondary);
    font-size: 2rem;
}

.book-card-title {
    font-size: 1.2rem;
    margin-bottom: 8px;
    color: var(--primary-color);
}

.book-card-author {
    color: var(--text-secondary);
    font-size: 0.9rem;
    margin-bottom: 8px;
}

.book-card-meta {
    display: flex;
    gap: 10px;
    flex-wrap: wrap;
}

.meta-item {
    font-size: 0.85rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 4px;
}

.book-card-body {
    padding: 20px;
}

.book-card-summary {
    font-size: 0.95rem;
    line-height: 1.5;
    color: var(--text-color);
}

.book-card-publisher {
    margin-top: 10px;
    font-size: 0.9rem;
    color: var(--text-secondary);
    display: flex;
    align-items: center;
    gap: 6px;
}

.book-card-footer {
    padding: 15px 20px;
    border-top: 1px solid var(--border-color);
    background: var(--bg-secondary);
}

.card-actions {
    display: flex;
    gap: 10px;
}

/* Pagination */
.pagination {
    margin-top: 2rem;
    display: flex;
    flex-direction: column;
    align-items: center;
    gap: 1rem;
}

.pagination-list {
    display: flex;
    gap: 4px;
    list-style: none;
}

.pagination-link {
    padding: 8px 16px;
    border: 1px solid var(--border-color);
    border-radius: var(--radius-sm);
    text-decoration: none;
    color: var(--text-color);
    transition: var(--transition);
    display: flex;
    align-items: center;
    gap: 6px;
}

.pagination-link:hover {
    background: var(--bg-secondary);
}

.pagination-link.active {
    background: var(--secondary-color);
    color: white;
    border-color: var(--secondary-color);
}

.pagination-ellipsis {
    padding: 8px;
    color: var(--text-secondary);
}

.pagination-info {
    color: var(--text-secondary);
    font-size: 0.9rem;
}

/* Empty State */
.empty-state {
    text-align: center;
    padding: 4rem 2rem;
}

.empty-icon {
    font-size: 4rem;
    color: var(--text-secondary);
    margin-bottom: 1rem;
}

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

.empty-text {
    color: var(--text-secondary);
    margin-bottom: 2rem;
}

/* Admin Panel */
.admin-panel {
    margin-top: 3rem;
    padding: 2rem;
    background: var(--bg-secondary);
    border-radius: var(--radius);
    border: 1px solid var(--border-color);
}

.admin-actions {
    display: flex;
    gap: 1rem;
    flex-wrap: wrap;
    margin-bottom: 1rem;
}

.admin-stats {
    color: var(--text-secondary);
    font-size: 0.95rem;
}

.text-link {
    color: var(--secondary-color);
    text-decoration: none;
}

.text-link:hover {
    text-decoration: underline;
}

.auth-required {
    text-align: center;
    padding: 2rem;
}

/* Footer */
.footer {
    background: var(--primary-color);
    color: white;
    padding: 2rem 0;
    margin-top: 3rem;
}

.footer-content {
    display: flex;
    justify-content: space-between;
    align-items: center;
    flex-wrap: wrap;
    gap: 2rem;
}

.footer-logo {
    display: flex;
    align-items: center;
    gap: 10px;
}

.logo-symbol {
    font-size: 2rem;
    color: #ff6600;
}

.logo-text {
    font-size: 1.2rem;
    font-weight: 600;
}

.footer-info {
    text-align: center;
}

.footer-info p {
    margin-bottom: 1rem;
}

.footer-links {
    display: flex;
    gap: 2rem;
    justify-content: center;
}

.footer-links a {
    color: white;
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 6px;
    transition: var(--transition);
}

.footer-links a:hover {
    color: #ff6600;
    transform: translateY(-2px);
}

/* Badge */
.badge {
    display: inline-block;
    padding: 4px 8px;
    background: var(--bg-secondary);
    border-radius: 12px;
    font-size: 0.85rem;
    color: var(--text-color);
    border: 1px solid var(--border-color);
}

/* Responsive */
@media (max-width: 768px) {
    .container {
        padding: 0 15px;
    }
    
    .header-content {
        flex-direction: column;
        gap: 1rem;
        text-align: center;
    }
    
    .search-wrapper {
        flex-direction: column;
    }
    
    .book-table {
        display: none;
    }
    
    .books-grid {
        display: grid;
    }
    
    .admin-actions {
        flex-direction: column;
    }
    
    .footer-content {
        flex-direction: column;
        text-align: center;
    }
    
    .footer-links {
        flex-direction: column;
        gap: 1rem;
    }
    
    .action-buttons {
        flex-wrap: wrap;
        justify-content: center;
    }
}

@media (max-width: 480px) {
    .catalog-title {
        font-size: 1.5rem;
    }
    
    .books-grid {
        grid-template-columns: 1fr;
    }
    
    .book-card-header {
        flex-direction: column;
        text-align: center;
    }
    
    .book-card-cover,
    .book-card-cover-placeholder {
        margin: 0 auto;
    }
}

/* Animations */
@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(10px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.book-card,
.book-table tr {
    animation: fadeIn 0.3s ease-out;
}

/* Accessibility */
.sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* Focus styles */
:focus-visible {
    outline: 2px solid var(--secondary-color);
    outline-offset: 2px;
}

/* Print styles */
@media print {
    .header,
    .search-form,
    .admin-panel,
    .theme-toggle,
    .action-buttons,
    .footer {
        display: none;
    }
    
    body {
        background: white;
        color: black;
    }
    
    .book-table {
        border: 1px solid #000;
    }
    
    .book-table th,
    .book-table td {
        border: 1px solid #000;
        padding: 8px;
    }
}