:root {
    --admin-primary: #232F3E;
    --admin-secondary: #37475A;
    --admin-accent: #FF9900;
    --admin-success: #067D62;
    --admin-danger: #C7511F;
    --admin-warning: #FFA41C;
    --admin-bg: #F5F5F5;
    --admin-white: #FFFFFF;
    --admin-border: #DDD;
    --admin-text: #0F1111;
    --admin-text-muted: #565959;
    --sidebar-width: 250px;
}

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

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, Oxygen, Ubuntu, sans-serif;
    background-color: var(--admin-bg);
    color: var(--admin-text);
    line-height: 1.5;
}

.admin-layout {
    display: flex;
    min-height: 100vh;
}

.admin-sidebar {
    width: var(--sidebar-width);
    background: var(--admin-primary);
    color: var(--admin-white);
    position: fixed;
    height: 100vh;
    overflow-y: auto;
}

.admin-sidebar-header {
    padding: 20px;
    border-bottom: 1px solid var(--admin-secondary);
}

.admin-sidebar-header h2 {
    font-size: 20px;
    color: var(--admin-accent);
}

.admin-sidebar-header p {
    font-size: 12px;
    color: #999;
    margin-top: 5px;
}

.admin-nav {
    padding: 20px 0;
}

.admin-nav ul {
    list-style: none;
}

.admin-nav li {
    margin-bottom: 5px;
}

.admin-nav a {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 12px 20px;
    color: #DDD;
    text-decoration: none;
    transition: all 0.2s;
}

.admin-nav a:hover,
.admin-nav a.active {
    background: var(--admin-secondary);
    color: var(--admin-accent);
}

.admin-nav .has-submenu > a {
    justify-content: flex-start;
}

.admin-nav .submenu-toggle {
    position: relative;
}

.admin-nav .submenu-arrow {
    margin-left: auto;
    transition: transform 0.2s;
}

.admin-nav .has-submenu.open > a .submenu-arrow {
    transform: rotate(180deg);
}

.admin-nav .submenu {
    display: none;
    padding-left: 20px;
    margin-top: 5px;
}

.admin-nav .has-submenu.open > .submenu {
    display: block;
}

.admin-nav .submenu li {
    margin-bottom: 2px;
}

.admin-nav .submenu a {
    padding: 8px 20px;
    font-size: 13px;
    border-left: 2px solid transparent;
}

.admin-nav .submenu a:hover {
    border-left-color: var(--admin-accent);
}

.admin-nav .submenu a.active {
    border-left-color: var(--admin-accent);
    background: rgba(255, 153, 0, 0.1);
}

.admin-nav .nav-section-label {
    font-size: 10px;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: #888;
    padding: 20px 20px 8px;
    margin-top: 8px;
    border-top: 1px solid var(--admin-secondary);
}

.admin-nav .nav-section-label:first-of-type {
    border-top: none;
    margin-top: 0;
}

.admin-nav .nav-divider {
    height: 1px;
    background: var(--admin-secondary);
    margin: 16px 20px;
}

.admin-nav .badge-count {
    background: #ef4444;
    color: white;
    font-size: 11px;
    padding: 2px 6px;
    border-radius: 10px;
    margin-left: auto;
}

.admin-nav a svg {
    width: 20px;
    height: 20px;
}

.admin-main {
    flex: 1;
    margin-left: var(--sidebar-width);
    min-height: 100vh;
}

.admin-header {
    background: var(--admin-white);
    padding: 15px 30px;
    border-bottom: 1px solid var(--admin-border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.admin-header h1 {
    font-size: 22px;
    color: var(--admin-primary);
}

.admin-header-actions {
    display: flex;
    gap: 15px;
    align-items: center;
}

.admin-content {
    padding: 30px;
}

.admin-card {
    background: var(--admin-white);
    border-radius: 8px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    padding: 25px;
    margin-bottom: 25px;
}

.admin-card-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    margin-bottom: 20px;
    padding-bottom: 15px;
    border-bottom: 1px solid var(--admin-border);
}

.admin-card-header h2 {
    font-size: 18px;
    color: var(--admin-primary);
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
    gap: 20px;
}

.stat-card {
    background: var(--admin-white);
    border-radius: 8px;
    padding: 25px;
    box-shadow: 0 1px 3px rgba(0,0,0,0.1);
    border-left: 4px solid var(--admin-accent);
}

.stat-card h3 {
    font-size: 14px;
    color: var(--admin-text-muted);
    margin-bottom: 10px;
}

.stat-card .number {
    font-size: 32px;
    font-weight: bold;
    color: var(--admin-primary);
}

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

.admin-table th,
.admin-table td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid var(--admin-border);
}

.admin-table th {
    background: var(--admin-bg);
    font-weight: 600;
    color: var(--admin-primary);
    font-size: 13px;
    text-transform: uppercase;
}

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

.admin-table img {
    width: 50px;
    height: 70px;
    object-fit: cover;
    border-radius: 4px;
}

.admin-btn {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 8px;
    padding: 10px 20px;
    font-size: 14px;
    font-weight: 600;
    text-align: center;
    border-radius: 6px;
    cursor: pointer;
    transition: all 0.2s;
    border: none;
    text-decoration: none;
    white-space: nowrap;
}

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

.admin-btn-primary {
    background: var(--admin-accent);
    color: var(--admin-primary);
}

.admin-btn-primary:hover {
    background: #E88B00;
    color: var(--admin-primary);
    text-decoration: none;
}

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

.admin-btn-secondary:hover {
    background: var(--admin-primary);
    text-decoration: none;
    color: var(--admin-white);
}

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

.admin-btn-danger:hover {
    background: #A8421A;
    text-decoration: none;
    color: var(--admin-white);
}

.admin-btn-sm {
    padding: 6px 12px;
    font-size: 12px;
    line-height: 1.4;
    min-width: auto;
    height: 28px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    box-sizing: border-box;
    vertical-align: middle;
}

.admin-table td .admin-btn-sm {
    margin: 2px;
}

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

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

.admin-form-group label {
    display: block;
    margin-bottom: 8px;
    font-weight: 500;
    color: var(--admin-text);
}

.admin-form-group input[type="text"],
.admin-form-group input[type="email"],
.admin-form-group input[type="password"],
.admin-form-group input[type="number"],
.admin-form-group input[type="date"],
.admin-form-group input[type="url"],
.admin-form-group select,
.admin-form-group textarea {
    width: 100%;
    padding: 10px 15px;
    border: 1px solid var(--admin-border);
    border-radius: 4px;
    font-size: 14px;
    transition: border-color 0.2s;
    background-color: var(--admin-white);
}

.admin-form-group input[type="url"] {
    font-family: 'Consolas', 'Monaco', monospace;
}

.admin-form-group input::placeholder {
    color: #999;
    font-style: italic;
}

.admin-form-group input:focus,
.admin-form-group select:focus,
.admin-form-group textarea:focus {
    outline: none;
    border-color: var(--admin-accent);
}

.admin-form-group textarea {
    min-height: 150px;
    resize: vertical;
}

.admin-form-group .help-text {
    font-size: 12px;
    color: var(--admin-text-muted);
    margin-top: 5px;
}

.admin-form-row {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 20px;
}

.admin-checkbox {
    display: flex;
    align-items: center;
    gap: 10px;
}

.admin-checkbox input {
    width: 18px;
    height: 18px;
}

.admin-alert {
    padding: 15px 20px;
    border-radius: 4px;
    margin-bottom: 20px;
}

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

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

.category-tree-admin {
    list-style: none;
}

.category-tree-admin li {
    padding: 10px 0;
    border-bottom: 1px solid var(--admin-border);
}

.category-tree-admin .level-1 {
    font-weight: bold;
}

.category-tree-admin .level-2 {
    padding-left: 30px;
    font-weight: normal;
}

.category-tree-admin .level-3 {
    padding-left: 60px;
    font-weight: normal;
    color: var(--admin-text-muted);
}

.category-actions {
    float: right;
}

.badge {
    display: inline-block;
    padding: 3px 8px;
    font-size: 11px;
    font-weight: 500;
    border-radius: 3px;
}

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

.badge-warning {
    background: var(--admin-warning);
    color: var(--admin-primary);
}

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

.login-page {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    background: linear-gradient(135deg, var(--admin-primary) 0%, var(--admin-secondary) 100%);
}

.login-box {
    background: var(--admin-white);
    padding: 40px;
    border-radius: 8px;
    box-shadow: 0 10px 40px rgba(0,0,0,0.2);
    width: 100%;
    max-width: 400px;
}

.login-box h1 {
    text-align: center;
    color: var(--admin-primary);
    margin-bottom: 30px;
    font-size: 24px;
}

.login-box .admin-btn {
    width: 100%;
    padding: 12px;
    font-size: 16px;
}

.pagination-admin {
    display: flex;
    justify-content: center;
    gap: 5px;
    margin-top: 20px;
}

.pagination-admin a,
.pagination-admin span {
    display: inline-block;
    padding: 6px 12px;
    border: 1px solid var(--admin-border);
    border-radius: 3px;
    color: var(--admin-text);
    text-decoration: none;
}

.pagination-admin a:hover {
    background: var(--admin-bg);
}

.pagination-admin .current {
    background: var(--admin-accent);
    color: var(--admin-primary);
    border-color: var(--admin-accent);
}

.admin-stats-row {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 20px;
}

.admin-stat-card {
    background: white;
    border-radius: 12px;
    padding: 20px;
    display: flex;
    align-items: center;
    gap: 15px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.08);
}

.stat-icon {
    width: 50px;
    height: 50px;
    border-radius: 12px;
    display: flex;
    align-items: center;
    justify-content: center;
    flex-shrink: 0;
}

.stat-content {
    flex: 1;
}

.stat-value {
    font-size: 24px;
    font-weight: 700;
    color: #232F3E;
}

.stat-label {
    font-size: 14px;
    color: #666;
    margin-top: 2px;
}

.stat-detail {
    font-size: 12px;
    color: #999;
    margin-top: 4px;
}

.top-books-list {
    padding: 10px 0;
}

.top-book-item {
    display: flex;
    align-items: center;
    gap: 12px;
    padding: 10px;
    border-bottom: 1px solid #f0f0f0;
}

.top-book-item:last-child {
    border-bottom: none;
}

.top-book-rank {
    width: 24px;
    height: 24px;
    background: #FF9900;
    color: white;
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 12px;
    font-weight: bold;
}

.top-book-cover {
    width: 40px;
    height: 55px;
    object-fit: cover;
    border-radius: 4px;
}

.top-book-cover-placeholder {
    width: 40px;
    height: 55px;
    background: #eee;
    border-radius: 4px;
}

.top-book-info {
    flex: 1;
}

.top-book-title {
    font-weight: 500;
    color: #232F3E;
}

.top-book-stats {
    font-size: 12px;
    color: #666;
    margin-top: 3px;
}

.revenue-chart {
    display: flex;
    align-items: flex-end;
    justify-content: space-around;
    height: 200px;
    padding: 20px;
    gap: 10px;
}

.chart-bar-container {
    display: flex;
    flex-direction: column;
    align-items: center;
    flex: 1;
    height: 100%;
}

.chart-bar {
    width: 100%;
    max-width: 60px;
    background: linear-gradient(180deg, #FF9900, #CC7A00);
    border-radius: 4px 4px 0 0;
    position: relative;
    min-height: 20px;
    margin-top: auto;
}

.chart-value {
    position: absolute;
    top: -25px;
    left: 50%;
    transform: translateX(-50%);
    font-size: 11px;
    font-weight: 600;
    color: #666;
    white-space: nowrap;
}

.chart-label {
    margin-top: 10px;
    font-size: 12px;
    color: #666;
}

.hamburger-btn {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    margin-right: 10px;
    border-radius: 6px;
    color: var(--admin-primary);
}

.hamburger-btn:hover {
    background: var(--admin-bg);
}

.sidebar-close {
    display: none;
    position: absolute;
    top: 15px;
    right: 15px;
    background: none;
    border: none;
    cursor: pointer;
    padding: 8px;
    border-radius: 6px;
    color: #fff;
}

.sidebar-close:hover {
    background: var(--admin-secondary);
}

.sidebar-overlay {
    display: none;
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    bottom: 0;
    background: rgba(0,0,0,0.5);
    z-index: 998;
}

.sidebar-overlay.active {
    display: block;
}

.header-left {
    display: flex;
    align-items: center;
}

.nav-divider {
    margin-top: 20px;
    padding-top: 15px;
    border-top: 1px solid var(--admin-secondary);
}

@media (max-width: 768px) {
    .hamburger-btn {
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    .sidebar-close {
        display: flex;
        align-items: center;
        justify-content: center;
    }
    
    .admin-sidebar {
        position: fixed;
        left: -280px;
        top: 0;
        width: 280px;
        height: 100vh;
        z-index: 999;
        transition: left 0.3s ease;
        overflow-y: auto;
    }
    
    .admin-sidebar.open {
        left: 0;
    }
    
    .admin-main {
        margin-left: 0;
    }
    
    .admin-header {
        padding: 12px 15px;
    }
    
    .admin-header h1 {
        font-size: 18px;
    }
    
    .welcome-text {
        display: none;
    }
    
    .admin-content {
        padding: 15px;
    }
    
    .admin-form-row {
        grid-template-columns: 1fr;
    }
    
    .stats-grid {
        grid-template-columns: 1fr 1fr;
        gap: 10px;
    }
    
    .stat-card {
        padding: 15px;
    }
    
    .stat-card .number {
        font-size: 24px;
    }
    
    .stat-card h3 {
        font-size: 12px;
    }
    
    .admin-stats-row {
        grid-template-columns: 1fr;
    }
    
    .admin-card {
        padding: 15px;
        margin-bottom: 15px;
    }
    
    .admin-card-header {
        flex-direction: column;
        gap: 10px;
        align-items: flex-start;
    }
    
    .admin-table th,
    .admin-table td {
        padding: 10px 8px;
        font-size: 13px;
    }
    
    .admin-btn {
        padding: 8px 12px;
        font-size: 13px;
    }
    
    .admin-btn-sm {
        padding: 5px 10px;
        font-size: 11px;
        height: 26px;
    }
}

@media (max-width: 480px) {
    .stats-grid {
        grid-template-columns: 1fr;
    }
    
    .admin-header h1 {
        font-size: 16px;
    }
    
    .admin-content {
        padding: 10px;
    }
}