:root {
    --primary-color: #3a86ff;
    --secondary-color: #8338ec;
    --accent-color: #ff006e;
    --light-bg: #f8f9fa;
    --dark-text: #212529;
    --light-text: #6c757d;
    --sidebar-width: 320px;
    --toolbar-height: 60px;
    --transition: all 0.3s ease;
    --border-radius: 8px;
    --box-shadow: 0 2px 10px rgba(0,0,0,0.1);
}

* {
    box-sizing: border-box;
}

body {
    font-family: 'Poppins', sans-serif;
    line-height: 1.6;
    color: var(--dark-text);
    background-color: #ffffff;
    margin: 0;
    padding: 0;
}

/* Navigation */
.navbar {
    box-shadow: 0 2px 10px rgba(0,0,0,0.05);
    padding: 15px 0;
    background-color: rgba(255, 255, 255, 0.95) !important;
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    position: sticky;
    top: 0;
    z-index: 1000;
}

.navbar-brand {
    font-family: 'Playfair Display', serif;
    font-weight: 700;
    font-size: 1.5rem;
    color: var(--primary-color) !important;
}

.nav-link {
    font-weight: 500;
    position: relative;
    margin: 0 10px;
    transition: var(--transition);
}

.nav-link:after {
    content: '';
    position: absolute;
    width: 0;
    height: 2px;
    bottom: 0;
    left: 0;
    background-color: var(--primary-color);
    transition: var(--transition);
}

.nav-link:hover:after,
.nav-link.active:after {
    width: 100%;
}

/* Download buttons styling for book reader */
.download-dropdown {
    position: relative;
    display: inline-block;
}

.download-dropdown-menu {
    position: absolute;
    top: 100%;
    right: 0;
    background: white;
    border-radius: 8px;
    box-shadow: 0 8px 25px rgba(0,0,0,0.15);
    border: none;
    padding: 8px;
    min-width: 120px;
    z-index: 1000;
    opacity: 0;
    visibility: hidden;
    transform: translateY(-10px);
    transition: all 0.3s ease;
}

.download-dropdown.active .download-dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.download-option {
    display: flex;
    align-items: center;
    padding: 6px 10px;
    text-decoration: none;
    color: var(--dark-text);
    border-radius: 6px;
    transition: all 0.2s ease;
    font-size: 0.8rem;
    font-weight: 500;
}

.download-option:hover {
    background-color: rgba(40, 167, 69, 0.1);
    color: #28a745;
    text-decoration: none;
}

.download-option i {
    margin-right: 6px;
    width: 14px;
    text-align: center;
}

.download-option.pdf-option i {
    color: #dc3545;
}

.download-option.epub-option i {
    color: #6f42c1;
}

.download-option:hover.pdf-option {
    background-color: rgba(220, 53, 69, 0.1);
    color: #dc3545;
}

.download-option:hover.epub-option {
    background-color: rgba(111, 66, 193, 0.1);
    color: #6f42c1;
}

/* Book Reader Container */
.book-reader-container {
    display: flex;
    height: calc(100vh - 80px);
    position: relative;
}

/* Sidebar */
.sidebar {
    width: var(--sidebar-width);
    background-color: var(--light-bg);
    border-right: 1px solid #dee2e6;
    padding: 20px;
    overflow-y: auto;
    transition: margin-left 0.3s ease;
    position: relative;
    z-index: 100;
    flex-shrink: 0;
}

.sidebar.collapsed {
    margin-left: calc(-1 * var(--sidebar-width));
}

.sidebar-header {
    display: flex;
    justify-content: flex-end;
    margin-bottom: 20px;
}

.sidebar-title {
    font-weight: 600;
    color: var(--dark-text);
    margin-bottom: 10px;
    font-size: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.5px;
}

/* Table of Contents */
.toc-container {
    max-height: 300px;
    overflow-y: auto;
    border: 1px solid #dee2e6;
    border-radius: var(--border-radius);
    padding: 10px;
    background-color: white;
}

.toc-item {
    padding: 8px 12px;
    cursor: pointer;
    border-radius: 4px;
    transition: var(--transition);
    font-size: 0.9rem;
    border-left: 3px solid transparent;
}

.toc-item.level-1 {
    font-weight: 600;
    margin-top: 10px;
}

.toc-item.level-2 {
    padding-left: 20px;
    font-size: 0.85rem;
}

.toc-item.level-3 {
    padding-left: 35px;
    font-size: 0.8rem;
    color: var(--light-text);
}

.toc-item:hover {
    background-color: rgba(58, 134, 255, 0.1);
    border-left-color: var(--primary-color);
}

.toc-item.active {
    background-color: rgba(58, 134, 255, 0.15);
    border-left-color: var(--primary-color);
    font-weight: 500;
}

.toc-item.level-1 {
    font-weight: 600;
    margin-top: 10px;
}

.toc-item.level-2 {
    padding-left: 20px;
    font-size: 0.85rem;
}

.toc-item.level-3 {
    padding-left: 35px;
    font-size: 0.8rem;
    color: var(--light-text);
}

/* Search Results */
.search-results {
    max-height: 200px;
    overflow-y: auto;
    border: 1px solid #dee2e6;
    border-radius: var(--border-radius);
    background-color: white;
    display: none;
}

.search-result-item {
    padding: 10px;
    cursor: pointer;
    border-bottom: 1px solid #f1f3f4;
    transition: var(--transition);
}

.search-result-item:hover {
    background-color: #e9ecef;
}

.search-result-item:last-child {
    border-bottom: none;
}

.search-result-title {
    font-weight: 500;
    font-size: 0.9rem;
    margin-bottom: 4px;
}

.search-result-context {
    font-size: 0.8rem;
    color: var(--light-text);
    line-height: 1.4;
}

.search-highlight {
    background-color: #ffeb3b;
    color: #000;
    padding: 1px 2px;
    border-radius: 2px;
}

.search-highlight-active {
    background-color: #ff9800;
    color: #fff;
    font-weight: bold;
}

.search-summary {
    padding: 10px;
    background: #f8f9fa;
    border-radius: 4px;
    margin-bottom: 10px;
}

.search-count {
    font-size: 14px;
    color: #6c757d;
    margin-bottom: 8px;
}

.search-navigation {
    display: flex;
    gap: 5px;
}

.search-navigation .btn {
    font-size: 12px;
    padding: 4px 8px;
}


/* Main Content */
.main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    background-color: white;
    position: relative;
}

/* Toolbar */
.toolbar {
    height: var(--toolbar-height);
    background-color: white;
    border-bottom: 1px solid #dee2e6;
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 20px;
}

.toolbar-left,
.toolbar-center,
.toolbar-right {
    display: flex;
    align-items: center;
    gap: 10px;
}

.book-title {
    font-weight: 600;
    font-size: 1.1rem;
    color: var(--dark-text);
    margin-left: 15px;
}

.pdf-navigation {
    display: flex;
    align-items: center;
    gap: 10px;
}

.page-info {
    display: flex;
    align-items: center;
    gap: 5px;
    font-size: 0.9rem;
}

/* Content Display */
.content-display {
    flex: 1;
    overflow: auto;
    position: relative;
}

/* Markdown Content */
.markdown-content,
.markdown-body {
    padding: 60px 80px;
    max-width: 900px;
    margin: 0 auto;
    line-height: 1.7;
    font-size: 16px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    color: #111827 !important;
    background-color: #ffffff;
}

.content-container {
    background-color: #ffffff;
    color: #111827;
}

/* Ensure all text elements have proper color in light mode */
.content-container *:not([data-theme="dark"] *) {
    color: inherit;
}

.content-display {
    color: #111827;
}

.markdown-content h1,
.markdown-content h2,
.markdown-content h3,
.markdown-content h4,
.markdown-content h5,
.markdown-content h6,
.markdown-body h1,
.markdown-body h2,
.markdown-body h3,
.markdown-body h4,
.markdown-body h5,
.markdown-body h6 {
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Helvetica, Arial, sans-serif;
    font-weight: 600;
    color: #111827 !important;
    margin-top: 2rem;
    margin-bottom: 1rem;
    scroll-margin-top: 80px;
}

.markdown-content h1 {
    font-size: 2.25rem;
    line-height: 2.5rem;
    border-bottom: 1px solid #e5e7eb;
    padding-bottom: 0.75rem;
    margin-bottom: 2rem;
    margin-top: 0;
}

.markdown-content h2 {
    font-size: 1.875rem;
    line-height: 2.25rem;
    margin-top: 3rem;
    margin-bottom: 1.5rem;
}

.markdown-content h3 {
    font-size: 1.5rem;
    line-height: 2rem;
    margin-top: 2.5rem;
    margin-bottom: 1rem;
}

.markdown-content h4 {
    font-size: 1.3rem;
}

.markdown-content h5 {
    font-size: 1.1rem;
}

.markdown-content h6 {
    font-size: 1rem;
    color: var(--light-text);
}

.markdown-content p,
.markdown-body p {
    margin-bottom: 1.25rem;
    line-height: 1.75;
    color: #1F2937 !important;
}

.markdown-content li,
.markdown-body li {
    color: #1F2937 !important;
}

.markdown-content td,
.markdown-content th,
.markdown-body td,
.markdown-body th {
    color: #1F2937 !important;
}

.markdown-content strong,
.markdown-body strong {
    color: #111827 !important;
    font-weight: 600;
}

.markdown-content em,
.markdown-body em {
    color: #374151 !important;
}

.markdown-content a,
.markdown-body a {
    color: #2563EB !important;
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: all 0.2s ease;
}

.markdown-content a:hover,
.markdown-body a:hover {
    color: #1D4ED8 !important;
    border-bottom-color: #1D4ED8;
}

.markdown-content blockquote,
.markdown-body blockquote {
    border-left: 4px solid #3b82f6;
    background-color: #f8fafc;
    padding: 1rem 1.5rem;
    margin: 1.5rem 0;
    color: #475569 !important;
    font-style: italic;
    border-radius: 0 var(--border-radius) var(--border-radius) 0;
}

.markdown-content blockquote p,
.markdown-body blockquote p {
    color: #475569 !important;
}

.markdown-content code {
    background-color: rgba(175, 184, 193, 0.2);
    padding: 0.125rem 0.375rem;
    border-radius: 6px;
    font-size: 0.875rem;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
    color: #e11d48;
}

.markdown-content pre {
    /* Don't override background - let Highlight.js handle it */
    border-radius: 8px;
    padding: 1rem;
    overflow-x: auto;
    margin: 1.5rem 0;
    font-size: 14px;
    font-family: 'SF Mono', Monaco, 'Cascadia Code', 'Roboto Mono', Consolas, 'Courier New', monospace;
}

.markdown-content pre code {
    background-color: transparent !important;
    padding: 0;
}

.markdown-content ul,
.markdown-content ol {
    margin-bottom: 1.2rem;
    padding-left: 30px;
}

.markdown-content li {
    margin-bottom: 0.5rem;
}

.markdown-content table {
    width: 100%;
    border-collapse: collapse;
    margin: 20px 0;
    box-shadow: var(--box-shadow);
    border-radius: var(--border-radius);
    overflow: hidden;
}

.markdown-content th,
.markdown-content td {
    padding: 12px 15px;
    text-align: left;
    border-bottom: 1px solid #dee2e6;
}

.markdown-content th {
    background-color: var(--primary-color);
    color: white;
    font-weight: 600;
}

.markdown-content tr:hover {
    background-color: rgba(58, 134, 255, 0.05);
}

.markdown-content img {
    max-width: 100%;
    height: auto;
    border-radius: var(--border-radius);
    box-shadow: var(--box-shadow);
    margin: 20px 0;
}

/* Tamil Font Support */
[lang="ta"],
.tamil-text {
    font-family: 'Hind Madurai', sans-serif;
    line-height: 1.9;
}

/* PDF styles removed - GitBook-style markdown only */

/* Print and PDF Styles */
@media print {
    .sidebar, .toolbar, .search-modal {
        display: none !important;
    }
    
    .main-content {
        width: 100% !important;
        margin-left: 0 !important;
    }
    
    .content-display {
        box-shadow: none !important;
        border: none !important;
        margin: 0 !important;
        padding: 20px !important;
    }
    
    .markdown-content {
        font-size: 12pt !important;
        line-height: 1.6 !important;
        color: #000 !important;
    }
    
    .markdown-content h1 {
        font-size: 20pt !important;
        page-break-before: always !important;
        margin-top: 0 !important;
        margin-bottom: 20pt !important;
    }
    
    .markdown-content h2 {
        font-size: 16pt !important;
        page-break-before: auto !important;
        page-break-after: avoid !important;
        margin-top: 20pt !important;
        margin-bottom: 12pt !important;
    }
    
    .markdown-content h3 {
        font-size: 14pt !important;
        page-break-after: avoid !important;
        margin-top: 16pt !important;
        margin-bottom: 8pt !important;
    }
    
    .markdown-content h4, .markdown-content h5, .markdown-content h6 {
        font-size: 12pt !important;
        page-break-after: avoid !important;
        margin-top: 12pt !important;
        margin-bottom: 6pt !important;
    }
    
    .markdown-content p {
        margin-bottom: 12pt !important;
        orphans: 3 !important;
        widows: 3 !important;
    }
    
    .markdown-content ul, .markdown-content ol {
        margin-bottom: 12pt !important;
        page-break-inside: avoid !important;
    }
    
    .markdown-content li {
        margin-bottom: 6pt !important;
    }
    
    .markdown-content pre {
        page-break-inside: avoid !important;
        margin: 12pt 0 !important;
        padding: 12pt !important;
        border: 1px solid #ccc !important;
        background: #f5f5f5 !important;
    }
    
    .markdown-content blockquote {
        page-break-inside: avoid !important;
        margin: 12pt 0 !important;
        padding: 12pt !important;
        border-left: 3pt solid #ccc !important;
    }
    
    .markdown-content img {
        max-width: 100% !important;
        page-break-inside: avoid !important;
        margin: 12pt 0 !important;
    }
    
    .markdown-content table {
        page-break-inside: avoid !important;
        margin: 12pt 0 !important;
        border-collapse: collapse !important;
    }
    
    .markdown-content th, .markdown-content td {
        border: 1px solid #ccc !important;
        padding: 6pt !important;
    }
}

/* PDF Export specific styles */
.pdf-export-mode {
    font-family: 'Hind Madurai', sans-serif !important;
}

.pdf-export-mode .markdown-content {
    max-width: none !important;
    padding: 40px !important;
    background: white !important;
}

.pdf-export-mode h1 {
    color: #2c3e50 !important;
    border-bottom: 2px solid #3498db !important;
    padding-bottom: 10px !important;
    margin-bottom: 30px !important;
}

.pdf-export-mode h2 {
    color: #34495e !important;
    margin-top: 40px !important;
    margin-bottom: 20px !important;
}

.pdf-export-mode h3 {
    color: #34495e !important;
    margin-top: 30px !important;
    margin-bottom: 15px !important;
}

.pdf-export-mode p {
    text-align: justify !important;
    margin-bottom: 15px !important;
    line-height: 1.8 !important;
}

.pdf-export-mode ul, .pdf-export-mode ol {
    margin-bottom: 20px !important;
    padding-left: 30px !important;
}

.pdf-export-mode li {
    margin-bottom: 8px !important;
    line-height: 1.6 !important;
}

.pdf-export-mode pre {
    background: #f8f9fa !important;
    border: 1px solid #e9ecef !important;
    border-radius: 4px !important;
    padding: 20px !important;
    margin: 20px 0 !important;
    overflow-x: auto !important;
}

.pdf-export-mode blockquote {
    border-left: 4px solid #3498db !important;
    background: #f8f9fa !important;
    padding: 15px 20px !important;
    margin: 20px 0 !important;
    font-style: italic !important;
}

/* Responsive Design */
@media (max-width: 1024px) {
    .sidebar {
        position: fixed; /* Use fixed to overlay content */
        top: 0;
        left: 0;
        height: 100%;
        z-index: 1030; /* Higher z-index for overlay */
        box-shadow: 0 5px 15px rgba(0,0,0,0.1);
        background-color: var(--light-bg);
        /* Override desktop transition */
        transition: transform 0.3s ease;
        transform: translateX(-100%);
        margin-left: 0; /* Reset desktop margin */
    }

    .sidebar.show {
        transform: translateX(0);
    }

    /* On mobile, 'collapsed' should behave like it's hidden */
    .sidebar.collapsed {
        transform: translateX(-100%);
    }
    
    /* Ensure sidebar overlay doesn't interfere with main content when hidden */
    .sidebar[style*="display: none"] {
        z-index: -1;
    }
    
    .main-content {
        width: 100%;
    }
    
    .markdown-content {
        padding: 20px;
    }
}

@media (max-width: 768px) {
    .toolbar {
        padding: 0 10px;
        flex-wrap: wrap;
        height: auto;
        min-height: var(--toolbar-height);
    }
    
    .toolbar-center {
        order: 3;
        width: 100%;
        justify-content: center;
        margin-top: 10px;
    }
    
    .book-title {
        font-size: 1rem;
        margin-left: 10px;
    }
    
    .markdown-content {
        padding: 15px;
    }
    
    .markdown-content h1 {
        font-size: 2rem;
    }
    
    .markdown-content h2 {
        font-size: 1.7rem;
    }
    
    .markdown-content h3 {
        font-size: 1.4rem;
    }
}

@media (max-width: 576px) {
    .sidebar {
        width: 280px;
    }
    
    .toolbar-left,
    .toolbar-right {
        gap: 5px;
    }
    
    .btn-group .btn {
        padding: 0.25rem 0.4rem;
    }
    
    .markdown-content {
        padding: 10px;
    }
}

/* Accessibility */
.btn:focus,
.form-control:focus,
.form-select:focus {
    box-shadow: 0 0 0 0.2rem rgba(58, 134, 255, 0.25);
    border-color: var(--primary-color);
}

/* High contrast mode support */
@media (prefers-contrast: high) {
    :root {
        --primary-color: #0056b3;
        --secondary-color: #6f42c1;
        --accent-color: #dc3545;
    }
}

/* Reduced motion support */
@media (prefers-reduced-motion: reduce) {
    * {
        animation-duration: 0.01ms !important;
        animation-iteration-count: 1 !important;
        transition-duration: 0.01ms !important;
    }
}

/* Print styles */
@media print {
    .navbar,
    .sidebar,
    .toolbar {
        display: none !important;
    }
    
    .main-content {
        width: 100% !important;
        height: auto !important;
    }
    
    .markdown-content {
        padding: 0 !important;
        max-width: none !important;
    }
}

/* Fullscreen mode */
.fullscreen-mode {
    position: fixed;
    top: 0;
    left: 0;
    width: 100vw;
    height: 100vh;
    z-index: 9999;
    background-color: white;
}

.fullscreen-mode .navbar {
    display: none;
}

.fullscreen-mode .book-reader-container {
    height: 100vh;
}

/* Loading states */
.loading {
    opacity: 0.6;
    pointer-events: none;
}

.spinner-border-sm {
    width: 1rem;
    height: 1rem;
}

/* Zoom levels */
.zoom-50 { transform: scale(0.5); }
.zoom-75 { transform: scale(0.75); }
.zoom-100 { transform: scale(1); }
.zoom-125 { transform: scale(1.25); }
.zoom-150 { transform: scale(1.5); }
.zoom-200 { transform: scale(2); }

/* Smooth scrolling */
html {
    scroll-behavior: smooth;
}

/* Selection styling */
::selection {
    background-color: rgba(58, 134, 255, 0.3);
    color: var(--dark-text);
}

::-moz-selection {
    background-color: rgba(58, 134, 255, 0.3);
    color: var(--dark-text);
}

/* Scrollbar styling */
::-webkit-scrollbar {
    width: 8px;
    height: 8px;
}

::-webkit-scrollbar-track {
    background-color: #f1f1f1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb {
    background-color: #c1c1c1;
    border-radius: 4px;
}

::-webkit-scrollbar-thumb:hover {
    background-color: #a8a8a8;
}

/* Reading Progress */
.reading-progress {
    width: 200px;
    height: 4px;
    background: rgba(255, 255, 255, 0.2);
    border-radius: 2px;
    margin-right: 15px;
    overflow: hidden;
}

.progress-bar {
    height: 100%;
    background: var(--primary-color);
    width: 0%;
    transition: width 0.3s ease;
}

/* Horizontal Layout Styles */
.horizontal-content {
    height: 100%;
    display: flex;
    flex-direction: column;
    position: relative;
}

.horizontal-pages-container {
    flex: 1;
    overflow: hidden;
    position: relative;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-bottom: 20px;
}

.horizontal-page {
    width: 100%;
    height: calc(100vh - 180px); /* Fit viewport minus toolbar/nav */
    max-height: calc(100vh - 180px);
    padding: 30px 40px;
    overflow-y: auto;
    overflow-x: hidden;
    background: white;
    font-size: 17px;
    line-height: 1.7;
    font-family: 'Noto Sans Tamil', 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
    color: #1a1a1a;
    box-sizing: border-box;
    /* Better text rendering */
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    text-rendering: optimizeLegibility;
    font-weight: 400;
    /* Custom scrollbar */
    scrollbar-width: thin;
    scrollbar-color: #CBD5E1 #F1F5F9;
}

.horizontal-page::-webkit-scrollbar {
    width: 8px;
}

.horizontal-page::-webkit-scrollbar-track {
    background: #F1F5F9;
    border-radius: 4px;
}

.horizontal-page::-webkit-scrollbar-thumb {
    background: #CBD5E1;
    border-radius: 4px;
}

.horizontal-page::-webkit-scrollbar-thumb:hover {
    background: #94A3B8;
}

.horizontal-page h1, .horizontal-page h2, .horizontal-page h3, 
.horizontal-page h4, .horizontal-page h5, .horizontal-page h6 {
    color: var(--primary-color);
    margin-top: 2rem;
    margin-bottom: 1rem;
    font-weight: 700;
    line-height: 1.4;
}

.horizontal-page h1 {
    font-size: 2.5rem;
    border-bottom: 3px solid var(--primary-color);
    padding-bottom: 0.5rem;
    font-weight: 800;
}

.horizontal-page h2 {
    font-size: 2rem;
    font-weight: 700;
}

.horizontal-page h3 {
    font-size: 1.5rem;
    font-weight: 600;
}

.horizontal-page p {
    margin-bottom: 1.2rem;
    text-align: justify;
    color: #2d2d2d;
    font-weight: 400;
    font-size: 18px;
    line-height: 1.9;
}

.horizontal-page img {
    max-width: 100%;
    height: auto;
    border-radius: 8px;
    margin: 20px 0;
    box-shadow: 0 4px 15px rgba(0,0,0,0.1);
}

.horizontal-page pre {
    background: #f8f9fa;
    border: 1px solid #e9ecef;
    border-radius: 6px;
    padding: 20px;
    margin: 20px 0;
    overflow-x: auto;
    font-size: 14px;
}

.horizontal-page code {
    background: #f8f9fa;
    padding: 2px 6px;
    border-radius: 4px;
    font-size: 14px;
}

.horizontal-page blockquote {
    border-left: 4px solid var(--primary-color);
    margin: 20px 0;
    padding: 15px 20px;
    background: #f8f9fa;
    border-radius: 0 6px 6px 0;
}

.horizontal-page ul, .horizontal-page ol {
    margin-bottom: 1.2rem;
    padding-left: 2rem;
}

.horizontal-page li {
    margin-bottom: 0.5rem;
    color: #2d2d2d;
    font-size: 17px;
    line-height: 1.8;
}

[data-theme="dark"] .horizontal-page li {
    color: #CBD5E1;
}

.horizontal-navigation {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 15px 20px;
    background: white;
    border-radius: 8px;
    box-shadow: 0 2px 10px rgba(0,0,0,0.1);
    margin-top: auto;
}

.page-indicator {
    font-weight: 500;
    color: var(--text-color);
    font-size: 14px;
}

.horizontal-navigation .btn {
    min-width: 120px;
}

.horizontal-navigation .btn:disabled {
    opacity: 0.5;
    cursor: not-allowed;
}

/* Layout Toggle Button Active State */
.layout-horizontal #layoutToggle {
    background: var(--primary-color);
    color: white;
    border-color: var(--primary-color);
}

.layout-horizontal #layoutToggle i {
    transform: rotate(90deg);
}

/* Responsive adjustments for horizontal layout */
@media (max-width: 768px) {
    .horizontal-page {
        padding: 20px 15px;
        font-size: 16px;
        height: calc(100vh - 140px); /* Less space for mobile toolbar */
        max-height: calc(100vh - 140px);
        line-height: 1.65;
    }
    
    .horizontal-page h1 {
        font-size: 1.6rem;
        margin-top: 1rem;
    }
    
    .horizontal-page h2 {
        font-size: 1.4rem;
        margin-top: 1rem;
    }
    
    .horizontal-page h3 {
        font-size: 1.2rem;
        margin-top: 0.8rem;
    }
    
    .horizontal-page p {
        font-size: 16px;
        margin-bottom: 1rem;
    }
    
    /* Better scrollbar for touch */
    .horizontal-page::-webkit-scrollbar {
        width: 4px;
    }
    
    .page-indicator {
        font-size: 12px;
    }
}

/* Mobile navbar fixes */
@media (max-width: 991.98px) {
    .navbar-toggler {
        border: 1px solid rgba(0,0,0,.1);
        padding: 0.25rem 0.5rem;
        font-size: 1.25rem;
        line-height: 1;
        background-color: transparent;
        border-radius: 0.25rem;
        transition: box-shadow 0.15s ease-in-out;
        z-index: 1050;
        position: relative;
    }
    
    .navbar-toggler:focus {
        text-decoration: none;
        outline: 0;
        box-shadow: 0 0 0 0.25rem rgba(13, 110, 253, 0.25);
    }
    
    .navbar-toggler-icon {
        display: inline-block;
        width: 1.5em;
        height: 1.5em;
        vertical-align: middle;
        background-image: url("data:image/svg+xml,%3csvg xmlns='http://www.w3.org/2000/svg' viewBox='0 0 30 30'%3e%3cpath stroke='rgba%2833, 37, 41, 0.75%29' stroke-linecap='round' stroke-miterlimit='10' stroke-width='2' d='M4 7h22M4 15h22M4 23h22'/%3e%3c/svg%3e");
        background-repeat: no-repeat;
        background-position: center;
        background-size: 100%;
    }
    
    .navbar-collapse {
        background-color: white;
        border-radius: 0.5rem;
        box-shadow: 0 0.5rem 1rem rgba(0, 0, 0, 0.15);
        margin-top: 0.5rem;
        padding: 1rem;
    }
    
    .navbar-nav {
        flex-direction: column;
    }
    
    .nav-link {
        padding: 0.5rem 1rem;
        margin: 0.25rem 0;
        border-radius: 0.25rem;
        transition: background-color 0.15s ease-in-out;
    }
    
    .nav-link:hover {
        background-color: rgba(13, 110, 253, 0.1);
    }
}


/* Feedback Section in Sidebar */
.feedback-section .btn {
    transition: var(--transition);
}

.feedback-section .btn:hover {
    transform: translateY(-1px);
    box-shadow: 0 4px 8px rgba(0,0,0,0.1);
}

/* Feedback Modal Overlay */
.feedback-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: rgba(0, 0, 0, 0.5);
    backdrop-filter: blur(4px);
    z-index: 2000;
    display: none;
    align-items: center;
    justify-content: center;
    animation: fadeIn 0.3s ease;
}

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

.comments-modal {
    background: white;
    border-radius: 12px;
    box-shadow: 0 20px 40px rgba(0,0,0,0.3);
    max-width: 800px;
    width: 95%;
    max-height: 85vh;
    overflow-y: auto;
    animation: slideUp 0.3s ease;
}

.feedback-header {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 20px 24px 16px;
    border-bottom: 1px solid #e9ecef;
}

.feedback-header h5 {
    margin: 0;
    color: var(--primary-color);
    font-weight: 600;
}

.feedback-header .btn-close {
    background: none;
    border: none;
    font-size: 1.5rem;
    cursor: pointer;
    color: var(--light-text);
    transition: var(--transition);
    padding: 4px 8px;
    border-radius: 4px;
}

.feedback-header .btn-close:hover {
    color: var(--dark-text);
    transform: scale(1.1);
}

.comments-content {
    padding: 24px;
    min-height: 400px;
}

.comments-content #disqus_thread_modal {
    min-height: 350px;
}

@keyframes fadeIn {
    from { opacity: 0; }
    to { opacity: 1; }
}

@keyframes slideUp {
    from { 
        opacity: 0;
        transform: translateY(30px);
    }
    to { 
        opacity: 1;
        transform: translateY(0);
    }
}

/* Mobile responsiveness */
@media (max-width: 768px) {
    .comments-modal {
        width: 95%;
        margin: 20px;
    }
    
    .comments-content {
        padding: 20px;
    }
}

/* Dark Mode Support for Book Reader */
[data-theme="dark"] {
    --light-bg: #1E293B;
    --dark-text: #F1F5F9;
    --light-text: #CBD5E1;
}

[data-theme="dark"] body {
    background-color: #0F172A;
    color: #F1F5F9;
}

[data-theme="dark"] .navbar {
    background-color: rgba(15, 23, 42, 0.95) !important;
    border-bottom: 1px solid #334155;
}

[data-theme="dark"] .navbar-brand {
    color: #818CF8 !important;
}

[data-theme="dark"] .nav-link {
    color: #CBD5E1 !important;
}

[data-theme="dark"] .nav-link:hover {
    color: #F1F5F9 !important;
}

[data-theme="dark"] .sidebar {
    background-color: #1E293B;
    border-right-color: #334155;
}

[data-theme="dark"] .sidebar-title {
    color: #F1F5F9;
}

[data-theme="dark"] .toc-container {
    background-color: #0F172A;
    border-color: #334155;
}

[data-theme="dark"] .toc-item {
    color: #CBD5E1;
}

[data-theme="dark"] .toc-item:hover {
    background-color: rgba(129, 140, 248, 0.1);
    color: #F1F5F9;
}

[data-theme="dark"] .toc-item.active {
    background-color: rgba(129, 140, 248, 0.15);
    color: #F1F5F9;
}

[data-theme="dark"] .search-results {
    background-color: #0F172A;
    border-color: #334155;
}

[data-theme="dark"] .search-result-item {
    color: #CBD5E1;
    border-bottom-color: #334155;
}

[data-theme="dark"] .search-result-item:hover {
    background-color: rgba(129, 140, 248, 0.1);
}

/* Main Content Dark Mode */
[data-theme="dark"] .main-content {
    background-color: #0F172A;
}

[data-theme="dark"] .content-container {
    background-color: #1E293B;
    color: #F1F5F9;
}

[data-theme="dark"] .markdown-body {
    color: #F1F5F9 !important;
}

[data-theme="dark"] .markdown-body h1,
[data-theme="dark"] .markdown-body h2,
[data-theme="dark"] .markdown-body h3,
[data-theme="dark"] .markdown-body h4,
[data-theme="dark"] .markdown-body h5,
[data-theme="dark"] .markdown-body h6 {
    color: #F1F5F9 !important;
}

[data-theme="dark"] .markdown-body p,
[data-theme="dark"] .markdown-body li,
[data-theme="dark"] .markdown-body td,
[data-theme="dark"] .markdown-body th {
    color: #CBD5E1 !important;
}

[data-theme="dark"] .markdown-body a {
    color: #818CF8 !important;
}

[data-theme="dark"] .markdown-body a:hover {
    color: #A5B4FC !important;
}

[data-theme="dark"] .markdown-body code {
    background-color: #334155 !important;
    color: #F1F5F9 !important;
    border-color: #475569 !important;
}

[data-theme="dark"] .markdown-body pre {
    background-color: #1E293B !important;
    border-color: #334155 !important;
}

[data-theme="dark"] .markdown-body pre code {
    background-color: transparent !important;
}

[data-theme="dark"] .markdown-body blockquote {
    border-left-color: #818CF8 !important;
    background-color: rgba(129, 140, 248, 0.05) !important;
    color: #CBD5E1 !important;
}

[data-theme="dark"] .markdown-body table {
    border-color: #334155 !important;
}

[data-theme="dark"] .markdown-body table th {
    background-color: #334155 !important;
    color: #F1F5F9 !important;
}

[data-theme="dark"] .markdown-body table td {
    border-color: #334155 !important;
}

[data-theme="dark"] .markdown-body table tr:nth-child(even) {
    background-color: rgba(51, 65, 85, 0.3) !important;
}

[data-theme="dark"] .markdown-body hr {
    border-color: #334155 !important;
}

/* Toolbar Dark Mode */
[data-theme="dark"] .toolbar {
    background-color: #1E293B;
    border-bottom-color: #334155;
}

[data-theme="dark"] .book-title {
    color: #F1F5F9;
}

[data-theme="dark"] .toolbar button {
    background-color: #475569;
    color: #FFFFFF;
    border: 1px solid #64748B !important;
}

[data-theme="dark"] .toolbar button:hover {
    background-color: #64748B;
    border-color: #94A3B8 !important;
}

/* Download dropdown dark mode */
[data-theme="dark"] .download-dropdown-menu {
    background-color: #1E293B;
    border: 1px solid #334155;
    box-shadow: 0 8px 25px rgba(0,0,0,0.5);
}

[data-theme="dark"] .download-option {
    color: #CBD5E1;
}

[data-theme="dark"] .download-option:hover {
    background-color: #334155;
}

/* Bookmarks dark mode */
[data-theme="dark"] .bookmark-item {
    background-color: #334155;
    color: #CBD5E1;
}

[data-theme="dark"] .bookmark-item:hover {
    background-color: #475569;
}

/* PDF Viewer dark mode */
[data-theme="dark"] #pdf-viewer {
    background-color: #0F172A;
}

/* Selection in dark mode */
[data-theme="dark"] ::selection {
    background: #3A86FF;
    color: #FFFFFF;
}

/* ===== PAGINATION ENHANCEMENTS ===== */

/* Smooth page transitions */
.horizontal-page {
    animation: fadeInPage 0.3s ease-in-out;
}

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

/* Page indicator styling */
.page-indicator {
    font-weight: 600;
    color: var(--primary-color);
    padding: 0 20px;
    font-size: 14px;
    white-space: nowrap;
}

[data-theme="dark"] .page-indicator {
    color: #60A5FA;
}

/* Horizontal navigation bar */
.horizontal-navigation {
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 15px;
    padding: 20px 0;
    border-top: 1px solid #E5E7EB;
    margin-top: 30px;
}

[data-theme="dark"] .horizontal-navigation {
    border-top-color: #334155;
}

.horizontal-navigation .btn {
    min-width: 120px;
    display: flex;
    align-items: center;
    gap: 8px;
    transition: all 0.2s ease;
}

.horizontal-navigation .btn:disabled {
    opacity: 0.4;
    cursor: not-allowed;
}

.horizontal-navigation .btn:not(:disabled):hover {
    transform: translateY(-2px);
    box-shadow: 0 4px 12px rgba(58, 134, 255, 0.2);
}

/* Mobile optimizations for pagination */
@media (max-width: 768px) {
    .horizontal-navigation {
        padding: 15px 10px;
        gap: 10px;
    }
    
    .horizontal-navigation .btn {
        min-width: 90px;
        font-size: 13px;
        padding: 8px 12px;
    }
    
    .page-indicator {
        font-size: 13px;
        padding: 0 10px;
    }
    
    /* Make swipe area larger */
    .horizontal-content {
        touch-action: pan-y;
        user-select: none;
    }
}

/* Touch feedback for mobile */
@media (hover: none) and (pointer: coarse) {
    .horizontal-navigation .btn:active {
        transform: scale(0.95);
    }
}

/* Progress bar enhancement */
.reading-progress .progress-bar {
    transition: width 0.4s ease;
}

/* Layout toggle button highlighting */
#layoutToggle.active {
    background-color: var(--primary-color);
    color: white;
}

[data-theme="dark"] #layoutToggle.active {
    background-color: #60A5FA;
}

/* Scrollbar dark mode */
[data-theme="dark"] ::-webkit-scrollbar-track {
    background: #1E293B;
}

[data-theme="dark"] ::-webkit-scrollbar-thumb {
    background: #475569;
}

/* Auto-hide toolbar on mobile */
@media (max-width: 768px) {
    .toolbar {
        transition: transform 0.3s ease, opacity 0.3s ease;
    }
    
    .toolbar.hidden {
        transform: translateY(-100%);
        opacity: 0;
        pointer-events: none;
    }
    
    .toolbar.visible {
        transform: translateY(0);
        opacity: 1;
        pointer-events: auto;
    }
}

/* Bottom swipe hint message - repositioned to top-right, mobile/tablet only */
.swipe-hint-bottom {
    position: fixed;
    top: 80px;
    right: 20px;
    background: linear-gradient(135deg, #667eea 0%, #764ba2 100%);
    color: white;
    padding: 12px 24px;
    border-radius: 25px;
    font-size: 14px;
    font-weight: 600;
    box-shadow: 0 4px 15px rgba(102, 126, 234, 0.4);
    opacity: 0;
    pointer-events: none;
    transition: opacity 0.3s ease;
    z-index: 1000;
    display: none; /* Hidden by default on desktop */
    align-items: center;
    gap: 8px;
    max-width: 280px;
}

/* Show swipe hint only on mobile and tablet devices */
@media (max-width: 1024px) {
    .swipe-hint-bottom {
        display: flex;
    }
}

.swipe-hint-bottom.show {
    opacity: 1;
}

.swipe-hint-bottom::before {
    content: '👆';
    font-size: 18px;
}

[data-theme="dark"] .swipe-hint-bottom {
    background: linear-gradient(135deg, #8b5cf6 0%, #6366f1 100%);
    box-shadow: 0 4px 15px rgba(139, 92, 246, 0.4);
}

/* Initial swipe hint indicator */
.horizontal-content::before {
    content: '← Swipe →';
    position: fixed;
    bottom: 80px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(79, 70, 229, 0.9);
    color: white;
    padding: 8px 16px;
    border-radius: 20px;
    font-size: 13px;
    font-weight: 600;
    opacity: 0;
    pointer-events: none;
    animation: swipeHint 3s ease-in-out;
    z-index: 100;
}

@keyframes swipeHint {
    0%, 100% { opacity: 0; }
    10%, 90% { opacity: 1; }
}

/* Dark mode for horizontal pagination */
[data-theme="dark"] .horizontal-page {
    background: #0F172A;
    color: #E2E8F0;
}

[data-theme="dark"] .horizontal-page p {
    color: #CBD5E1;
}

[data-theme="dark"] .horizontal-page h1,
[data-theme="dark"] .horizontal-page h2,
[data-theme="dark"] .horizontal-page h3,
[data-theme="dark"] .horizontal-page h4,
[data-theme="dark"] .horizontal-page h5,
[data-theme="dark"] .horizontal-page h6 {
    color: #60A5FA;
}

[data-theme="dark"] .horizontal-page pre {
    background: #1E293B;
    border-color: #334155;
}

[data-theme="dark"] .horizontal-page code {
    background: #1E293B;
    color: #E2E8F0;
}

[data-theme="dark"] .horizontal-page blockquote {
    background: #1E293B;
    border-left-color: #60A5FA;
}

/* Code playground in pagination mode - auto-fit without scrolling */
.horizontal-page .code-playground {
    margin: 20px 0;
    /* Prevent touch gestures from triggering page swipe */
    touch-action: pan-y pinch-zoom;
}

.horizontal-page .playground-code {
    overflow-y: hidden !important;
    resize: none !important;
    box-sizing: border-box !important;
    /* Prevent swipe gestures on textarea */
    touch-action: pan-y;
}

.horizontal-page .playground-output {
    /* Allow vertical scrolling in output, prevent horizontal swipe */
    touch-action: pan-y;
}

.horizontal-page .playground-btn {
    /* Prevent any touch gesture on buttons */
    touch-action: none;
}

.horizontal-page .playground-editor {
    overflow: visible;
}

[data-theme="dark"] ::-webkit-scrollbar-thumb:hover {
    background: #64748B;
}