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

:root {
    --primary: #6366f1;
    --primary-dark: #4f46e5;
    --secondary: #8b5cf6;
    --bg: #0f172a;
    --bg-light: #1e293b;
    --bg-lighter: #334155;
    --text: #f1f5f9;
    --text-muted: #94a3b8;
    --border: #334155;
    --success: #10b981;
    --error: #ef4444;
    --warning: #f59e0b;
}

body {
    font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, 'Helvetica Neue', Arial, sans-serif;
    background: var(--bg);
    color: var(--text);
    line-height: 1.6;
    overflow-x: hidden;
    padding-bottom: 100px;
}

header {
    background: var(--bg-light);
    border-bottom: 1px solid var(--border);
    padding: 1rem 2rem;
    position: sticky;
    top: 0;
    z-index: 100;
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo {
    font-size: 1.5rem;
    font-weight: bold;
    color: var(--primary);
}

nav {
    display: flex;
    gap: 1rem;
    align-items: center;
}

nav a {
    color: var(--text);
    text-decoration: none;
    padding: 0.5rem 1rem;
    border-radius: 0.5rem;
    transition: background 0.2s;
}

nav a:hover, nav a.active {
    background: var(--bg-lighter);
}

.user-info {
    display: flex;
    align-items: center;
    gap: 1rem;
}

.btn {
    padding: 0.5rem 1.5rem;
    border: none;
    border-radius: 0.5rem;
    cursor: pointer;
    font-size: 1rem;
    transition: all 0.2s;
    background: var(--primary);
    color: white;
}

.btn:hover {
    background: var(--primary-dark);
    transform: translateY(-1px);
}

.btn-secondary {
    background: var(--bg-lighter);
}

.btn-secondary:hover {
    background: var(--bg-lighter);
    opacity: 0.8;
}

.btn-small {
    padding: 0.25rem 0.75rem;
    font-size: 0.85rem;
}

.container {
    max-width: 1400px;
    margin: 0 auto;
    padding: 2rem;
}

.auth-container {
    max-width: 400px;
    margin: 4rem auto;
    background: var(--bg-light);
    padding: 2rem;
    border-radius: 1rem;
    border: 1px solid var(--border);
}

.auth-tabs {
    display: flex;
    gap: 1rem;
    margin-bottom: 2rem;
}

.auth-tab {
    flex: 1;
    padding: 0.75rem;
    background: transparent;
    border: 1px solid var(--border);
    color: var(--text);
    cursor: pointer;
    border-radius: 0.5rem;
    transition: all 0.2s;
}

.auth-tab.active {
    background: var(--primary);
    border-color: var(--primary);
}

.form-group {
    margin-bottom: 1.5rem;
}

.form-group label {
    display: block;
    margin-bottom: 0.5rem;
    color: var(--text-muted);
}

.form-group input, .form-group select {
    width: 100%;
    padding: 0.75rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text);
    font-size: 1rem;
}

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

.error-message {
    color: var(--error);
    margin-top: 0.5rem;
    font-size: 0.9rem;
}

.search-bar {
    margin-bottom: 2rem;
}

.search-bar input {
    width: 100%;
    padding: 1rem;
    background: var(--bg-light);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text);
    font-size: 1rem;
}

.view-tabs {
    display: flex;
    gap: 0.5rem;
    margin-bottom: 1.5rem;
}

.view-tab {
    padding: 0.5rem 1rem;
    background: var(--bg-light);
    border: 1px solid var(--border);
    color: var(--text);
    border-radius: 0.5rem;
    cursor: pointer;
}

.view-tab.active {
    background: var(--primary);
    border-color: var(--primary);
}

.books-grid, .series-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(280px, 1fr));
    gap: 1.5rem;
}

.book-card, .series-card {
    background: var(--bg-light);
    border-radius: 1rem;
    overflow: hidden;
    border: 1px solid var(--border);
    transition: transform 0.2s, box-shadow 0.2s;
    cursor: pointer;
}

.book-card:hover, .series-card:hover {
    transform: translateY(-4px);
    box-shadow: 0 10px 30px rgba(0, 0, 0, 0.3);
}

.book-cover, .series-cover {
    width: 100%;
    aspect-ratio: 2/3;
    object-fit: cover;
    background: var(--bg-lighter);
}

.book-info, .series-info {
    padding: 1rem;
}

.book-title, .series-title {
    font-size: 1.1rem;
    font-weight: 600;
    margin-bottom: 0.5rem;
    color: var(--text);
}

.book-meta, .series-meta {
    font-size: 0.9rem;
    color: var(--text-muted);
    margin-bottom: 0.5rem;
}

.book-description {
    font-size: 0.85rem;
    color: var(--text-muted);
    display: -webkit-box;
    -webkit-line-clamp: 2;
    -webkit-box-orient: vertical;
    overflow: hidden;
}

.status-badge {
    display: inline-block;
    padding: 0.2rem 0.6rem;
    border-radius: 999px;
    font-size: 0.75rem;
    background: var(--bg-lighter);
    color: var(--text-muted);
    margin-top: 0.5rem;
}

.player-container {
    max-width: 1200px;
    margin: 0 auto;
}

.book-header {
    display: flex;
    gap: 2rem;
    margin-bottom: 2rem;
}

.book-cover-large {
    width: 300px;
    aspect-ratio: 2/3;
    object-fit: cover;
    border-radius: 1rem;
    background: var(--bg-lighter);
}

.book-details {
    flex: 1;
}

.book-details h1 {
    font-size: 2rem;
    margin-bottom: 1rem;
}

.book-details .meta {
    color: var(--text-muted);
    margin-bottom: 1rem;
}

.book-details .description {
    color: var(--text-muted);
    line-height: 1.8;
}

.book-actions {
    display: flex;
    flex-wrap: wrap;
    gap: 0.5rem;
    margin-top: 1rem;
}

.chapters-list {
    margin-top: 2rem;
}

.chapter-item {
    background: var(--bg-light);
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 0.5rem;
    transition: background 0.2s;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border: 1px solid var(--border);
    gap: 1rem;
}

.chapter-item:hover {
    background: var(--bg-lighter);
}

.chapter-item.active {
    border-color: var(--primary);
    background: var(--bg-lighter);
}

.chapter-info {
    flex: 1;
    cursor: pointer;
}

.chapter-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
}

.chapter-meta {
    font-size: 0.85rem;
    color: var(--text-muted);
}

.audio-player {
    position: fixed;
    bottom: 0;
    left: 0;
    right: 0;
    background: var(--bg-light);
    border-top: 1px solid var(--border);
    padding: 1.5rem 2rem;
    z-index: 1000;
    display: none;
}

.audio-player.active {
    display: block;
}

.player-controls {
    display: flex;
    align-items: center;
    gap: 1rem;
    max-width: 1400px;
    margin: 0 auto;
}

.player-info {
    flex: 1;
    min-width: 0;
}

.player-title {
    font-weight: 600;
    margin-bottom: 0.25rem;
    white-space: nowrap;
    overflow: hidden;
    text-overflow: ellipsis;
}

.player-chapter {
    font-size: 0.9rem;
    color: var(--text-muted);
}

.player-buttons {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.player-btn {
    background: transparent;
    border: none;
    color: var(--text);
    cursor: pointer;
    font-size: 1.5rem;
    padding: 0.5rem;
    border-radius: 0.5rem;
    transition: background 0.2s;
}

.player-btn:hover {
    background: var(--bg-lighter);
}

.player-progress {
    flex: 1;
    margin: 0 1rem;
}

.progress-bar {
    width: 100%;
    height: 6px;
    background: var(--bg-lighter);
    border-radius: 3px;
    cursor: pointer;
    position: relative;
}

.progress-filled {
    height: 100%;
    background: var(--primary);
    border-radius: 3px;
    transition: width 0.1s;
}

.progress-time {
    display: flex;
    justify-content: space-between;
    font-size: 0.85rem;
    color: var(--text-muted);
    margin-top: 0.25rem;
}

.speed-control {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.speed-btn {
    background: var(--bg-lighter);
    border: 1px solid var(--border);
    color: var(--text);
    padding: 0.25rem 0.75rem;
    border-radius: 0.25rem;
    cursor: pointer;
    font-size: 0.9rem;
}

.speed-btn.active {
    background: var(--primary);
    border-color: var(--primary);
}

.notes-section {
    margin-top: 2rem;
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: 1rem;
    border: 1px solid var(--border);
}

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

.notes-list {
    margin-top: 1rem;
}

.note-item {
    background: var(--bg);
    padding: 1rem;
    border-radius: 0.5rem;
    margin-bottom: 0.5rem;
    border: 1px solid var(--border);
}

.note-time {
    color: var(--primary);
    font-size: 0.9rem;
    margin-bottom: 0.5rem;
}

.note-text {
    color: var(--text);
}

.add-note-form textarea {
    width: 100%;
    padding: 0.75rem;
    background: var(--bg);
    border: 1px solid var(--border);
    border-radius: 0.5rem;
    color: var(--text);
    font-size: 1rem;
    font-family: inherit;
    resize: vertical;
    min-height: 100px;
}

.stats-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
    gap: 1.5rem;
    margin-bottom: 2rem;
}

.stat-card {
    background: var(--bg-light);
    padding: 1.5rem;
    border-radius: 1rem;
    border: 1px solid var(--border);
}

.stat-value {
    font-size: 2rem;
    font-weight: bold;
    color: var(--primary);
    margin-bottom: 0.5rem;
}

.stat-label {
    color: var(--text-muted);
    font-size: 0.9rem;
}

.loading {
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
}

.spinner {
    border: 3px solid var(--bg-lighter);
    border-top: 3px solid var(--primary);
    border-radius: 50%;
    width: 40px;
    height: 40px;
    animation: spin 1s linear infinite;
    margin: 0 auto 1rem;
}

@keyframes spin {
    0% { transform: rotate(0deg); }
    100% { transform: rotate(360deg); }
}

.empty-state {
    text-align: center;
    padding: 3rem;
    color: var(--text-muted);
}

.toast-container {
    position: fixed;
    top: 1rem;
    right: 1rem;
    z-index: 2000;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.toast {
    padding: 0.75rem 1.25rem;
    border-radius: 0.5rem;
    background: var(--bg-light);
    border: 1px solid var(--border);
    box-shadow: 0 4px 12px rgba(0, 0, 0, 0.3);
    animation: slideIn 0.3s ease;
}

.toast.error { border-color: var(--error); color: var(--error); }
.toast.success { border-color: var(--success); color: var(--success); }

@keyframes slideIn {
    from { transform: translateX(100%); opacity: 0; }
    to { transform: translateX(0); opacity: 1; }
}

.back-link {
    display: inline-block;
    margin-bottom: 1rem;
    color: var(--primary);
    text-decoration: none;
    cursor: pointer;
}

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

@media (max-width: 768px) {
    .container { padding: 1rem; }
    header { padding: 1rem; flex-wrap: wrap; }
    nav { order: 3; width: 100%; margin-top: 1rem; }
    .book-header { flex-direction: column; }
    .book-cover-large { width: 100%; }
    .player-controls { flex-wrap: wrap; }
    .player-progress { width: 100%; margin: 0.5rem 0; }
}