:root {
    /* Light Mode Colors */
    --bg-primary: #f8fafc;
    --bg-secondary: #ffffff;
    --bg-sidebar: #f1f5f9;
    --text-primary: #0f172a;
    --text-secondary: #475569;
    --text-muted: #94a3b8;
    --accent: #d97706;
    /* Amber-600 */
    --accent-hover: #b45309;
    /* Amber-700 */
    --border: #e2e8f0;
    --highlight: rgba(251, 191, 36, 0.2);
    /* Soft Yellow Highlight */
    --shadow: 0 4px 6px -1px rgb(0 0 0 / 0.05), 0 2px 4px -2px rgb(0 0 0 / 0.05);
    --transition: all 0.25s cubic-bezier(0.4, 0, 0.2, 1);

    /* Typography Options */
    --font-ui: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-reading: system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Helvetica, Arial, sans-serif;
    --font-size-base: 20px;
    --line-height-base: 1.8;
}

[data-theme="dark"] {
    /* Dark Mode Colors */
    --bg-primary: #0f172a;
    /* Slate 900 */
    --bg-secondary: #1e293b;
    /* Slate 800 */
    --bg-sidebar: #0b0f19;
    --text-primary: #f8fafc;
    --text-secondary: #cbd5e1;
    /* Slate 300 */
    --text-muted: #64748b;
    /* Slate 500 */
    --accent: #fbbf24;
    /* Amber-400 */
    --accent-hover: #f59e0b;
    /* Amber-500 */
    --border: #334155;
    /* Slate 700 */
    --highlight: rgba(245, 158, 11, 0.25);
    --shadow: 0 10px 15px -3px rgb(0 0 0 / 0.3), 0 4px 6px -4px rgb(0 0 0 / 0.3);
}

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

body {
    background-color: var(--bg-primary);
    color: var(--text-primary);
    font-family: var(--font-ui);
    min-height: 100vh;
    min-height: 100dvh;
    display: flex;
    overflow: hidden;
    transition: var(--transition);
}

/* Loading Overlay */
#global-loader {
    position: fixed;
    inset: 0;
    background-color: var(--bg-primary);
    display: flex;
    flex-direction: column;
    justify-content: center;
    align-items: center;
    z-index: 9999;
    transition: opacity 0.5s ease;
}

.spinner {
    width: 50px;
    height: 50px;
    border: 4px solid var(--border);
    border-top: 4px solid var(--accent);
    border-radius: 50%;
    animation: spin 1s linear infinite;
    margin-bottom: 20px;
}

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

    100% {
        transform: rotate(360deg);
    }
}

/* Sidebar Styling */
#sidebar {
    width: 320px;
    background-color: var(--bg-sidebar);
    border-right: 1px solid var(--border);
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
    flex-shrink: 0;
    transition: var(--transition);
    z-index: 100;
}

#sidebar.collapsed {
    margin-left: -320px;
}

.sidebar-header {
    padding: 24px;
    border-bottom: 1px solid var(--border);
    display: flex;
    justify-content: space-between;
    align-items: center;
}

.logo-area {
    display: flex;
    align-items: center;
    gap: 10px;
    color: var(--accent);
    font-family: var(--font-ui);
    font-weight: 700;
    font-size: 20px;
    letter-spacing: -0.5px;
}

.logo-area span {
    color: var(--text-primary);
}

.sidebar-close-btn {
    background: none;
    border: none;
    color: var(--text-secondary);
    cursor: pointer;
    padding: 4px;
    border-radius: 6px;
    display: none;
    /* Mobile only */
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

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

.search-container {
    padding: 16px 24px;
    position: relative;
}

.search-input {
    width: 100%;
    padding: 10px 16px 10px 40px;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 8px;
    color: var(--text-primary);
    font-family: var(--font-ui);
    font-size: 14px;
    outline: none;
    transition: var(--transition);
}

.search-input:focus {
    border-color: var(--accent);
    box-shadow: 0 0 0 2px rgba(217, 119, 6, 0.15);
}

.search-icon {
    position: absolute;
    left: 36px;
    top: 50%;
    transform: translateY(-50%);
    color: var(--text-muted);
    pointer-events: none;
    width: 16px;
    height: 16px;
}

.sidebar-tabs {
    display: flex;
    padding: 0 24px;
    gap: 8px;
    margin-bottom: 12px;
}

.tab-btn {
    flex: 1;
    padding: 8px;
    border: none;
    background: none;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 600;
    cursor: pointer;
    border-bottom: 2px solid transparent;
    transition: var(--transition);
}

.tab-btn.active {
    color: var(--accent);
    border-bottom-color: var(--accent);
}

.books-scroll-area {
    flex: 1;
    overflow-y: auto;
    padding: 0 16px 24px 16px;
}

/* Custom Scrollbar */
::-webkit-scrollbar {
    width: 6px;
    height: 6px;
}

::-webkit-scrollbar-track {
    background: transparent;
}

::-webkit-scrollbar-thumb {
    background: var(--border);
    border-radius: 3px;
}

::-webkit-scrollbar-thumb:hover {
    background: var(--text-muted);
}

.book-group-title {
    font-size: 11px;
    font-weight: 700;
    text-transform: uppercase;
    letter-spacing: 1px;
    color: var(--text-muted);
    margin: 16px 8px 8px 8px;
}

.book-item {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 10px 12px;
    border-radius: 8px;
    cursor: pointer;
    transition: var(--transition);
    margin-bottom: 2px;
    user-select: none;
}

.book-item:hover {
    background-color: var(--bg-secondary);
    transform: translateX(4px);
}

.book-item.active {
    background-color: var(--accent);
    color: #ffffff;
}

.book-name {
    font-weight: 500;
    font-size: 15px;
}

.book-meta {
    font-size: 12px;
    color: var(--text-muted);
    transition: var(--transition);
}

.book-item.active .book-meta {
    color: rgba(255, 255, 255, 0.8);
}

/* Main Content Styling */
#main-content {
    flex: 1;
    display: flex;
    flex-direction: column;
    height: 100vh;
    height: 100dvh;
    position: relative;
}

/* Top Header */
.app-header {
    height: 72px;
    padding: 0 32px;
    display: flex;
    justify-content: space-between;
    align-items: center;
    border-bottom: 1px solid var(--border);
    background-color: var(--bg-secondary);
    z-index: 10;
    transition: var(--transition);
}

.header-left {
    display: flex;
    align-items: center;
    gap: 16px;
}

.icon-btn {
    background: none;
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    padding: 8px;
    border-radius: 8px;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
}

.icon-btn:hover {
    background-color: var(--bg-primary);
    color: var(--accent);
    border-color: var(--accent);
}

.current-location {
    font-size: 18px;
    font-weight: 600;
    display: flex;
    align-items: center;
    gap: 8px;
}

.header-right {
    display: flex;
    align-items: center;
    gap: 12px;
}

/* Dropdown/Settings Panels */
.settings-menu {
    position: relative;
}

.settings-dropdown {
    position: absolute;
    right: 0;
    top: calc(100% + 8px);
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 16px;
    width: 280px;
    box-shadow: var(--shadow);
    display: none;
    flex-direction: column;
    gap: 16px;
    z-index: 50;
}

.settings-dropdown.show {
    display: flex;
}

.setting-section-title {
    font-size: 12px;
    font-weight: 700;
    color: var(--text-muted);
    text-transform: uppercase;
    letter-spacing: 0.5px;
    margin-bottom: 8px;
}

.setting-row {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.font-selector {
    display: flex;
    border: 1px solid var(--border);
    border-radius: 8px;
    overflow: hidden;
}

.font-btn {
    flex: 1;
    padding: 8px;
    border: none;
    background: none;
    color: var(--text-secondary);
    font-size: 13px;
    font-weight: 500;
    cursor: pointer;
    transition: var(--transition);
}

.font-btn.active {
    background-color: var(--accent);
    color: #ffffff;
}

.slider-container {
    display: flex;
    align-items: center;
    gap: 12px;
}

.font-slider {
    flex: 1;
    accent-color: var(--accent);
    cursor: pointer;
}

/* Reader Area */
.reader-outer {
    flex: 1;
    overflow-y: auto;
    padding: 48px 24px;
    scroll-behavior: smooth;
}

.reader-inner {
    max-width: 720px;
    margin: 0 auto;
    min-height: 100%;
    display: flex;
    flex-direction: column;
}

/* Chapter Title in Reader */
.reader-title-area {
    text-align: center;
    margin-bottom: 48px;
}

.reader-title-book {
    font-size: 36px;
    font-family: var(--font-ui);
    font-weight: 700;
    margin-bottom: 8px;
    color: var(--accent);
}

.reader-title-chapter {
    font-size: 20px;
    font-weight: 500;
    color: var(--text-secondary);
    letter-spacing: 1px;
    text-transform: uppercase;
}

/* Chapter Selection Grid overlay when clicking title */
.chapter-grid-container {
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    border-radius: 12px;
    padding: 24px;
    margin-bottom: 32px;
    box-shadow: var(--shadow);
    display: none;
    animation: fadeIn 0.2s ease;
}

@keyframes fadeIn {
    from {
        opacity: 0;
        transform: translateY(-10deg);
    }

    to {
        opacity: 1;
        transform: translateY(0);
    }
}

.chapter-grid-container.show {
    display: block;
}

.chapter-grid {
    display: grid;
    grid-template-columns: repeat(auto-fill, minmax(50px, 1fr));
    gap: 10px;
    max-height: 250px;
    overflow-y: auto;
    padding: 4px;
}

.chapter-cell {
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    border: 1px solid var(--border);
    border-radius: 8px;
    font-weight: 600;
    cursor: pointer;
    transition: var(--transition);
    background-color: var(--bg-primary);
}

.chapter-cell:hover {
    border-color: var(--accent);
    color: var(--accent);
    background-color: var(--bg-secondary);
    transform: scale(1.05);
}

.chapter-cell.active {
    background-color: var(--accent);
    color: #ffffff;
    border-color: var(--accent);
}

/* Verses List Styling */
.verses-container {
    font-family: var(--font-reading);
    font-size: var(--font-size-base);
    line-height: var(--line-height-base);
    transition: opacity 0.15s ease;
    display: flex;
    flex-direction: column;
    gap: 20px;
    opacity: 1;
}

.verse-line {
    display: block;
    position: relative;
    padding: 8px 12px;
    border-radius: 6px;
    cursor: pointer;
    transition: var(--transition);
}

.verse-line:hover {
    background-color: var(--bg-secondary);
}

.verse-line.highlighted {
    background-color: var(--highlight);
}

.verse-num {
    font-family: var(--font-ui);
    font-weight: 700;
    font-size: 0.85em;
    color: var(--accent);
    margin-right: 8px;
    user-select: none;
    display: inline-block;
    width: 24px;
}

.verse-text {
    color: var(--text-primary);
    word-break: keep-all;
}

/* Pinned Navigation Buttons */
.nav-chapter-btn-fixed {
    position: absolute;
    top: 110px;
    width: 48px;
    height: 48px;
    border-radius: 50%;
    background-color: var(--bg-secondary);
    border: 1px solid var(--border);
    color: var(--text-secondary);
    cursor: pointer;
    display: flex;
    align-items: center;
    justify-content: center;
    transition: var(--transition);
    box-shadow: var(--shadow);
    z-index: 90;
}

.nav-chapter-btn-fixed:hover {
    border-color: var(--accent);
    color: var(--accent);
    transform: scale(1.1);
    background-color: var(--bg-primary);
}

.nav-chapter-btn-fixed:disabled {
    opacity: 0.3;
    cursor: not-allowed;
    transform: none;
    border-color: var(--border);
    color: var(--text-muted);
    background-color: var(--bg-secondary);
}

#prev-chapter-btn {
    left: 24px;
}

#next-chapter-btn {
    right: 24px;
}

/* Mobile Floating Menu Trigger */
.sidebar-toggle-mobile {
    position: fixed;
    bottom: 24px;
    right: 24px;
    width: 56px;
    height: 56px;
    border-radius: 50%;
    background-color: var(--accent);
    color: #ffffff;
    border: none;
    box-shadow: 0 4px 10px rgba(217, 119, 6, 0.4);
    display: none;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 99;
    transition: var(--transition);
}

.sidebar-toggle-mobile:hover {
    background-color: var(--accent-hover);
    transform: scale(1.1);
}

/* Skeleton Loading inside Reader */
.skeleton-loader {
    display: none;
    flex-direction: column;
    gap: 20px;
    width: 100%;
}

.skeleton-loader.active {
    display: flex;
}

.skeleton-line {
    height: 20px;
    background: linear-gradient(90deg, var(--border) 25%, var(--bg-secondary) 50%, var(--border) 75%);
    background-size: 200% 100%;
    animation: loading 1.5s infinite;
    border-radius: 4px;
}

@keyframes loading {
    0% {
        background-position: 200% 0;
    }

    100% {
        background-position: -200% 0;
    }
}

/* Media Queries for Responsive Design */
@media (max-width: 900px) {
    #sidebar {
        position: fixed;
        top: 0;
        bottom: 0;
        left: 0;
        box-shadow: 10px 0 30px rgba(0, 0, 0, 0.15);
    }

    .sidebar-close-btn {
        display: flex;
    }

    .sidebar-toggle-mobile {
        display: flex;
    }

    #sidebar.collapsed {
        margin-left: -320px;
    }

    .reader-outer {
        padding-bottom: 96px;
    }
}

@media (max-width: 600px) {
    .app-header {
        padding: 0 16px;
    }

    .reader-outer {
        padding: 32px 16px 96px 16px;
    }

    .reader-title-book {
        font-size: 28px;
    }

    .current-location {
        font-size: 16px;
    }

    .nav-chapter-btn-fixed {
        top: 84px;
        width: 40px;
        height: 40px;
    }
    #prev-chapter-btn {
        left: 12px;
    }
    #next-chapter-btn {
        right: 12px;
    }
}