@import url('https://fonts.googleapis.com/css2?family=Noto+Sans+Bengali:wght@400;500;600;700&family=Noto+Serif+Bengali:wght@400;500;600;700&family=Outfit:wght@400;500;600;700&display=swap');

:root {
    /* Typography */
    --font-body: 'Noto Serif Bengali', serif;
    --font-ui: 'Noto Sans Bengali', 'Outfit', sans-serif;
    --font-title: 'Noto Sans Bengali', 'Outfit', sans-serif;

    /* Colors - Light Theme (default) */
    --bg-primary: #fdfbf7;
    --bg-secondary: #f6f3eb;
    --bg-drawer: #faf7f0;
    --border-color: #e2dcd2;
    --text-primary: #2d2621;
    --text-secondary: #5e5045;
    --text-muted: #8d7b6e;
    --accent-color: #d97706;        /* Golden amber */
    --accent-hover: #b45309;
    --accent-light: #fef3c7;
    --card-bg: #ffffff;
    --shadow-sm: 0 1px 3px rgba(45,38,33,0.05);
    --shadow-md: 0 4px 6px -1px rgba(45,38,33,0.08), 0 2px 4px -1px rgba(45,38,33,0.04);
    --shadow-lg: 0 10px 15px -3px rgba(45,38,33,0.08), 0 4px 6px -2px rgba(45,38,33,0.04);
    
    --header-bg: rgba(253, 251, 247, 0.85);
    --footnote-bg: #f9f6ef;
    
    /* Transitions */
    --transition-fast: 0.15s ease;
    --transition-normal: 0.25s ease;
}

[data-theme="dark"] {
    /* Colors - Dark Theme */
    --bg-primary: #12110f;
    --bg-secondary: #1a1916;
    --bg-drawer: #171613;
    --border-color: #2e2a24;
    --text-primary: #e7e5e4;
    --text-secondary: #a8a29e;
    --text-muted: #78716c;
    --accent-color: #f59e0b;        /* Gold */
    --accent-hover: #fbbf24;
    --accent-light: #2d2412;
    --card-bg: #1c1a17;
    --shadow-sm: 0 1px 3px rgba(0,0,0,0.3);
    --shadow-md: 0 4px 6px -1px rgba(0,0,0,0.4), 0 2px 4px -1px rgba(0,0,0,0.3);
    --shadow-lg: 0 10px 15px -3px rgba(0,0,0,0.5), 0 4px 6px -2px rgba(0,0,0,0.3);
    
    --header-bg: rgba(12, 11, 9, 0.85);
    --footnote-bg: #1a1815;
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-body);
    line-height: 1.85;
    font-size: 1.25rem;
    transition: background-color var(--transition-normal), color var(--transition-normal);
    min-height: 100vh;
    display: flex;
    flex-direction: column;
    -webkit-font-smoothing: antialiased;
}

/* Fixed Top Header */
.fixed-header {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 70px;
    background-color: var(--header-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--border-color);
    z-index: 100;
    transition: background-color var(--transition-normal), border-color var(--transition-normal);
}

.header-container {
    max-width: 1200px;
    height: 100%;
    margin: 0 auto;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
}

.header-title {
    font-family: var(--font-title);
    font-weight: 700;
    font-size: 1.5rem;
    text-align: center;
}

.home-link {
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.home-link:hover {
    color: var(--accent-color);
}

.title-separator {
    color: var(--border-color);
    font-weight: 300;
}

.subtitle {
    font-size: 1.1rem;
    color: var(--text-secondary);
    font-weight: 400;
}

/* Buttons */
.menu-btn, .theme-btn, .close-btn {
    background: none;
    border: none;
    color: var(--text-primary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.5rem;
    border-radius: 8px;
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.menu-btn {
    font-family: var(--font-ui);
    font-weight: 600;
    font-size: 1.05rem;
    gap: 0.5rem;
    border: 1px solid var(--border-color);
    padding: 0.4rem 0.8rem;
}

.menu-btn:hover, .theme-btn:hover, .close-btn:hover {
    background-color: var(--bg-secondary);
    color: var(--accent-color);
}

/* Main Content Area */
.main-content {
    flex: 1;
    margin-top: 70px;
    width: 100%;
    display: flex;
    flex-direction: column;
}

.content-container {
    max-width: 800px;
    width: 100%;
    margin: 0 auto;
    padding: 3rem 1.5rem 5rem 1.5rem;
}

/* Typography styles inside content */
h1 {
    font-family: var(--font-title);
    font-size: 2.2rem;
    line-height: 1.35;
    margin-bottom: 2rem;
    color: var(--text-primary);
    border-bottom: 2px solid var(--border-color);
    padding-bottom: 0.75rem;
}

h2 {
    font-family: var(--font-title);
    font-size: 1.75rem;
    margin-top: 2.5rem;
    margin-bottom: 1.25rem;
    color: var(--text-primary);
}

h3 {
    font-family: var(--font-title);
    font-size: 1.45rem;
    margin-top: 2rem;
    margin-bottom: 1rem;
    color: var(--text-secondary);
}

p {
    margin-bottom: 1.5rem;
    text-align: justify;
}

blockquote {
    border-left: 4px solid var(--accent-color);
    padding: 0.5rem 1.5rem;
    margin: 1.5rem 0;
    background-color: var(--bg-secondary);
    font-style: italic;
    color: var(--text-secondary);
    border-radius: 0 8px 8px 0;
}

/* Footnotes */
.footnotes {
    font-family: var(--font-body);
    font-size: 0.95rem;
    line-height: 1.6;
    color: var(--text-secondary);
    background-color: var(--footnote-bg);
    border-right: 3px solid var(--accent-color);
    padding: 0.6rem 1.2rem;
    margin: 0.75rem 0 2rem auto;
    max-width: 85%;
    border-radius: 6px 0 0 6px;
    font-style: italic;
    box-shadow: var(--shadow-sm);
}

/* Navigation Drawer */
.nav-drawer {
    position: fixed;
    top: 0;
    left: -320px;
    width: 320px;
    height: 100%;
    background-color: var(--bg-drawer);
    border-right: 1px solid var(--border-color);
    z-index: 1000;
    transition: transform var(--transition-normal);
    display: flex;
    flex-direction: column;
    box-shadow: var(--shadow-lg);
}

.nav-drawer.open {
    transform: translateX(320px);
}

.drawer-header {
    height: 70px;
    padding: 0 1.5rem;
    display: flex;
    align-items: center;
    justify-content: space-between;
    border-bottom: 1px solid var(--border-color);
}

.drawer-title {
    font-family: var(--font-title);
    font-size: 1.35rem;
    font-weight: 700;
    color: var(--text-primary);
}

.drawer-content {
    flex: 1;
    overflow-y: auto;
    padding: 1.5rem;
}

.drawer-section-title {
    font-family: var(--font-ui);
    font-size: 0.85rem;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 0.05em;
    color: var(--text-muted);
    margin-top: 1.5rem;
    margin-bottom: 0.5rem;
    padding-bottom: 0.25rem;
    border-bottom: 1px dashed var(--border-color);
}

.drawer-menu {
    list-style: none;
}

.drawer-item {
    display: block;
    font-family: var(--font-ui);
    font-size: 1.05rem;
    color: var(--text-primary);
    text-decoration: none;
    padding: 0.6rem 0.8rem;
    border-radius: 6px;
    margin-bottom: 0.25rem;
    transition: background-color var(--transition-fast), color var(--transition-fast);
}

.drawer-item:hover {
    background-color: var(--bg-secondary);
    color: var(--accent-color);
}

.drawer-item.active {
    background-color: var(--accent-light);
    color: var(--accent-color);
    font-weight: 600;
}

.drawer-overlay {
    position: fixed;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background-color: rgba(0, 0, 0, 0.4);
    z-index: 999;
    opacity: 0;
    pointer-events: none;
    transition: opacity var(--transition-normal);
}

.drawer-overlay.open {
    opacity: 1;
    pointer-events: auto;
}

/* Index Landing Page Styles */
.toc-title {
    text-align: center;
    font-size: 2.5rem;
    font-family: var(--font-title);
    margin-bottom: 1rem;
    color: var(--text-primary);
}

.toc-subtitle {
    text-align: center;
    font-family: var(--font-ui);
    color: var(--text-secondary);
    font-size: 1.25rem;
    margin-bottom: 3rem;
}

.front-matter-cards {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
    gap: 1.25rem;
    margin-bottom: 4rem;
}

.fm-card {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    padding: 1.5rem 1rem;
    text-align: center;
    text-decoration: none;
    color: var(--text-primary);
    font-family: var(--font-ui);
    font-weight: 600;
    font-size: 1.15rem;
    box-shadow: var(--shadow-sm);
    transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast), color var(--transition-fast);
}

.fm-card:hover {
    transform: translateY(-2px);
    border-color: var(--accent-color);
    box-shadow: var(--shadow-md);
    color: var(--accent-color);
}

.parva-section {
    background-color: var(--card-bg);
    border: 1px solid var(--border-color);
    border-radius: 16px;
    margin-bottom: 2.5rem;
    padding: 2rem;
    box-shadow: var(--shadow-sm);
    scroll-margin-top: 90px; /* Offset for sticky header when jumping to id */
}

.parva-header {
    font-family: var(--font-title);
    font-size: 1.6rem;
    font-weight: 700;
    color: var(--accent-color);
    margin-bottom: 1.5rem;
    border-bottom: 1px solid var(--border-color);
    padding-bottom: 0.5rem;
}

.chapter-links {
    list-style: none;
    display: flex;
    flex-direction: column;
    gap: 0.75rem;
}

.chapter-link-item {
    display: flex;
    gap: 1.25rem;
    font-size: 1.2rem;
    align-items: baseline;
}

.chapter-num {
    color: var(--text-muted);
    font-family: var(--font-ui);
    font-weight: 500;
    min-width: 2.5rem;
    text-align: right;
}

.chapter-title-link {
    color: var(--text-primary);
    text-decoration: none;
    transition: color var(--transition-fast);
    line-height: 1.5;
}

.chapter-title-link:hover {
    color: var(--accent-color);
}

/* Pagination inside chapters */
.chapter-navigation {
    display: flex;
    justify-content: space-between;
    gap: 1.5rem;
    margin-top: 5rem;
    padding-top: 2rem;
    border-top: 1px solid var(--border-color);
}

.nav-link {
    flex: 1;
    display: flex;
    flex-direction: column;
    padding: 1.25rem 1.5rem;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border-color);
    border-radius: 12px;
    text-decoration: none;
    color: var(--text-primary);
    transition: transform var(--transition-fast), border-color var(--transition-fast), box-shadow var(--transition-fast);
    box-shadow: var(--shadow-sm);
    max-width: 48%;
}

.nav-link:hover {
    transform: translateY(-2px);
    border-color: var(--accent-color);
    box-shadow: var(--shadow-md);
}

.nav-link.prev {
    align-items: flex-start;
}

.nav-link.next {
    align-items: flex-end;
    text-align: right;
}

.nav-label {
    font-family: var(--font-ui);
    font-size: 0.85rem;
    font-weight: 600;
    color: var(--text-muted);
    text-transform: uppercase;
    margin-bottom: 0.25rem;
}

.nav-name {
    font-family: var(--font-title);
    font-weight: 700;
    font-size: 1.15rem;
    color: var(--accent-color);
    transition: color var(--transition-fast);
}

.nav-link:hover .nav-name {
    color: var(--text-primary);
}

/* Responsive Design */
@media (max-width: 768px) {
    body {
        font-size: 1.18rem;
    }
    
    .content-container {
        padding: 2rem 1rem 4rem 1rem;
    }
    
    h1 {
        font-size: 1.85rem;
    }
    
    h2 {
        font-size: 1.5rem;
    }
    
    .menu-text {
        display: none;
    }
    
    .subtitle {
        display: none;
    }
    
    .footnotes {
        max-width: 100%;
        border-radius: 0;
        border-left: 3px solid var(--accent-color);
        border-right: none;
        text-align: left;
    }
    
    .chapter-navigation {
        flex-direction: column;
        gap: 1rem;
    }
    
    .nav-link {
        max-width: 100%;
    }
}