/**
 * Idea Prokashon - World-Class International EPUB & PDF Reader Engine Stylesheet
 * Supports: 5 Reading Themes, Kalpurush & Curated Bengali Typography,
 * Spread & Scroll Layouts, In-Book Search, 5-Color Highlights & Notes, DRM Watermarks.
 */

/* Kalpurush Local & WebFont Declaration */
@font-face {
    font-family: 'Kalpurush';
    src: url('/fonts/kalpurush/kalpurush.woff2') format('woff2'),
         url('/fonts/kalpurush/kalpurush.ttf') format('truetype');
    font-weight: normal;
    font-style: normal;
    font-display: swap;
}

:root {
    --reader-bg: #f8fafc;
    --reader-surface: #ffffff;
    --reader-surface-subtle: #f1f5f9;
    --reader-text: #0f172a;
    --reader-text-muted: #64748b;
    --reader-border: #e2e8f0;
    --reader-border-subtle: #f1f5f9;
    --reader-nav-bg: rgba(255, 255, 255, 0.96);
    --reader-nav-border: #e2e8f0;
    --reader-primary: #0284c7;
    --reader-primary-hover: #0369a1;
    --reader-primary-light: rgba(2, 132, 199, 0.12);
    --reader-accent: #0ea5e9;
    --reader-watermark-color: rgba(15, 23, 42, 0.08);
    --reader-shadow: 0 2px 12px rgba(0, 0, 0, 0.05);
    --reader-shadow-lg: 0 10px 30px rgba(0, 0, 0, 0.10);
    --reader-highlight-yellow: rgba(254, 240, 138, 0.55);
    --reader-highlight-green: rgba(167, 243, 208, 0.55);
    --reader-highlight-pink: rgba(251, 207, 232, 0.55);
    --reader-highlight-blue: rgba(186, 230, 253, 0.55);
    --reader-highlight-purple: rgba(233, 213, 255, 0.55);
}

/* 1. Theme: Warm Sepia */
[data-theme="sepia"] {
    --reader-bg: #f4ece1;
    --reader-surface: #fdf6ec;
    --reader-surface-subtle: #ebdcc9;
    --reader-text: #3c2a1a;
    --reader-text-muted: #7c6753;
    --reader-border: #e2d1bc;
    --reader-border-subtle: #ece1d1;
    --reader-nav-bg: rgba(253, 246, 236, 0.96);
    --reader-nav-border: #e2d1bc;
    --reader-primary: #8b5e3c;
    --reader-primary-hover: #6d4629;
    --reader-primary-light: rgba(139, 94, 60, 0.14);
    --reader-accent: #b45309;
    --reader-watermark-color: rgba(60, 42, 26, 0.08);
    --reader-shadow: 0 2px 12px rgba(60, 42, 26, 0.08);
}

/* 2. Theme: Dark Mode (OLED) */
[data-theme="dark"] {
    --reader-bg: #090d16;
    --reader-surface: #111827;
    --reader-surface-subtle: #1f2937;
    --reader-text: #f3f4f6;
    --reader-text-muted: #9ca3af;
    --reader-border: #1f2937;
    --reader-border-subtle: #1e293b;
    --reader-nav-bg: rgba(17, 24, 39, 0.96);
    --reader-nav-border: #1f2937;
    --reader-primary: #38bdf8;
    --reader-primary-hover: #7dd3fc;
    --reader-primary-light: rgba(56, 189, 248, 0.16);
    --reader-accent: #0ea5e9;
    --reader-watermark-color: rgba(243, 244, 246, 0.07);
    --reader-shadow: 0 2px 16px rgba(0, 0, 0, 0.5);
}

/* 3. Theme: Solarized Sand */
[data-theme="sand"] {
    --reader-bg: #eee8d5;
    --reader-surface: #fdf6e3;
    --reader-surface-subtle: #e6dfc8;
    --reader-text: #586e75;
    --reader-text-muted: #839496;
    --reader-border: #dcd4be;
    --reader-border-subtle: #e3dbc5;
    --reader-nav-bg: rgba(253, 246, 227, 0.96);
    --reader-nav-border: #dcd4be;
    --reader-primary: #b58900;
    --reader-primary-hover: #967000;
    --reader-primary-light: rgba(181, 137, 0, 0.14);
    --reader-accent: #cb4b16;
    --reader-watermark-color: rgba(88, 110, 117, 0.08);
    --reader-shadow: 0 2px 12px rgba(88, 110, 117, 0.08);
}

/* 4. Theme: Mint Green */
[data-theme="mint"] {
    --reader-bg: #e6f4ea;
    --reader-surface: #f0fdf4;
    --reader-surface-subtle: #dcfce7;
    --reader-text: #14532d;
    --reader-text-muted: #166534;
    --reader-border: #bbf7d0;
    --reader-border-subtle: #d1fae5;
    --reader-nav-bg: rgba(240, 253, 244, 0.96);
    --reader-nav-border: #bbf7d0;
    --reader-primary: #16a34a;
    --reader-primary-hover: #15803d;
    --reader-primary-light: rgba(22, 163, 74, 0.14);
    --reader-accent: #059669;
    --reader-watermark-color: rgba(20, 83, 45, 0.08);
    --reader-shadow: 0 2px 12px rgba(20, 83, 45, 0.08);
}

/* Global Reset & Typography */
* {
    box-sizing: border-box;
}

body.reader-active {
    font-family: 'Kalpurush', 'SolaimanLipi', 'Hind Siliguri', 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
    background-color: var(--reader-bg);
    color: var(--reader-text);
    margin: 0;
    padding: 0;
    height: 100vh;
    width: 100vw;
    display: flex;
    flex-direction: column;
    overflow: hidden;
    transition: background-color 0.25s ease, color 0.25s ease;
    -webkit-font-smoothing: antialiased;
    -moz-osx-font-smoothing: grayscale;
    -webkit-touch-callout: none;
    user-select: none;
}

/* Top Header Navbar */
.reader-head {
    height: 54px;
    background-color: var(--reader-nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid var(--reader-nav-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 0.75rem;
    z-index: 100;
    box-shadow: var(--reader-shadow);
    flex-shrink: 0;
    white-space: nowrap;
    overflow: hidden;
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
}

.reader-head-left,
.reader-head-right {
    display: flex;
    align-items: center;
    gap: 0.35rem;
    flex-shrink: 0;
}

.reader-head-center {
    flex: 1;
    min-width: 0;
    max-width: 440px;
    text-align: center;
    padding: 0 0.6rem;
    overflow: hidden;
}

/* Immersive Zen Mode Auto-Hiding */
body.zen-mode .reader-head {
    transform: translateY(-100%);
    opacity: 0;
    pointer-events: none;
}
body.zen-mode .reader-foot {
    transform: translateY(100%);
    opacity: 0;
    pointer-events: none;
}
body.zen-mode .reader-main {
    padding: 0;
}

/* Interactive Buttons */
.reader-btn {
    background: transparent;
    border: 1px solid var(--reader-border);
    color: var(--reader-text);
    border-radius: 8px;
    padding: 0.32rem 0.62rem;
    font-size: 0.82rem;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    gap: 0.35rem;
    cursor: pointer;
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    font-weight: 500;
    text-decoration: none;
    white-space: nowrap;
    user-select: none;
}
.reader-btn:hover {
    background-color: var(--reader-surface-subtle);
    color: var(--reader-primary);
    border-color: var(--reader-primary);
    transform: translateY(-1px);
}
.reader-btn:active {
    transform: translateY(0);
}

.reader-btn-primary {
    background-color: var(--reader-primary-light);
    color: var(--reader-primary);
    border-color: var(--reader-primary);
    font-weight: 600;
}
.reader-btn-primary:hover {
    background-color: var(--reader-primary);
    color: #ffffff !important;
}

.reader-btn-icon {
    width: 34px;
    height: 34px;
    padding: 0;
    border-radius: 8px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
}

/* Main Reading Area */
.reader-main {
    flex: 1;
    display: flex;
    position: relative;
    overflow: hidden;
    padding: 0.4rem 0.65rem;
    transition: padding 0.3s ease;
}

#epub-viewer-wrapper {
    width: 100%;
    height: 100%;
    max-width: 960px;
    margin: 0 auto;
    background-color: var(--reader-surface);
    box-shadow: var(--reader-shadow-lg);
    border-radius: 10px;
    position: relative;
    overflow: hidden;
    border: 1px solid var(--reader-border);
    transition: max-width 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    padding: 0;
}

#epub-viewer-wrapper.dual-spread-active {
    max-width: 1440px;
}

/* Dual Page Spread Center Spine Shadow Effect */
#epub-viewer-wrapper.dual-spread-active::after {
    content: '';
    position: absolute;
    top: 0;
    bottom: 0;
    left: 50%;
    width: 32px;
    transform: translateX(-50%);
    pointer-events: none;
    background: linear-gradient(to right, rgba(0, 0, 0, 0.01), rgba(0, 0, 0, 0.12) 50%, rgba(0, 0, 0, 0.01));
    z-index: 25;
    opacity: 0.9;
}

[data-theme="sepia"] #epub-viewer-wrapper.dual-spread-active::after {
    background: linear-gradient(to right, rgba(60, 42, 26, 0.02), rgba(60, 42, 26, 0.18) 50%, rgba(60, 42, 26, 0.02));
}

[data-theme="dark"] #epub-viewer-wrapper.dual-spread-active::after {
    background: linear-gradient(to right, rgba(0, 0, 0, 0.2), rgba(0, 0, 0, 0.65) 50%, rgba(0, 0, 0, 0.2));
}

#epub-viewer {
    width: 100%;
    height: 100%;
    position: relative;
}

/* DRM Dynamic Anti-Piracy Watermark Overlay */
.drm-watermark-layer {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    pointer-events: none;
    z-index: 30;
    display: grid;
    grid-template-columns: repeat(3, 1fr);
    grid-template-rows: repeat(3, 1fr);
    align-items: center;
    justify-items: center;
    overflow: hidden;
    opacity: 0.75;
}
.watermark-unit {
    transform: rotate(-24deg);
    font-size: 12px;
    font-weight: 700;
    color: var(--reader-watermark-color);
    white-space: nowrap;
    padding: 20px;
    user-select: none;
    letter-spacing: 0.5px;
}

/* Side Navigation Arrows (Flip Buttons) */
.nav-arrow {
    position: absolute;
    top: 50%;
    transform: translateY(-50%);
    width: 44px;
    height: 44px;
    background: var(--reader-surface);
    border: 1px solid var(--reader-border);
    color: var(--reader-text);
    border-radius: 50%;
    display: flex;
    align-items: center;
    justify-content: center;
    cursor: pointer;
    z-index: 40;
    box-shadow: var(--reader-shadow);
    transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
    opacity: 0.75;
}
.nav-arrow:hover {
    opacity: 1;
    background: var(--reader-primary);
    color: #ffffff;
    border-color: var(--reader-primary);
    transform: translateY(-50%) scale(1.1);
    box-shadow: 0 6px 16px var(--reader-primary-light);
}
.nav-prev { left: 14px; }
.nav-next { right: 14px; }

body.zen-mode .nav-arrow {
    opacity: 0.2;
}
body.zen-mode .nav-arrow:hover {
    opacity: 1;
}

@media (max-width: 768px) {
    .nav-arrow {
        width: 36px;
        height: 36px;
        font-size: 0.82rem;
    }
    .nav-prev { left: 4px; }
    .nav-next { right: 4px; }
    .reader-head { padding: 0 0.4rem; }
    .reader-main { padding: 0.2rem; }
    #epub-viewer-wrapper { border-radius: 6px; }
}

/* Bottom Footer Status */
.reader-foot {
    height: 38px;
    background-color: var(--reader-nav-bg);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-top: 1px solid var(--reader-nav-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0 0.85rem;
    font-size: 0.78rem;
    color: var(--reader-text-muted);
    z-index: 50;
    flex-shrink: 0;
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.3s ease;
}

/* Interactive Page Slider Scrubber */
.reader-scrubber {
    -webkit-appearance: none;
    appearance: none;
    width: 100%;
    height: 5px;
    background: var(--reader-border);
    border-radius: 999px;
    outline: none;
    transition: background 0.2s ease;
}
.reader-scrubber::-webkit-slider-thumb {
    -webkit-appearance: none;
    appearance: none;
    width: 15px;
    height: 15px;
    background: var(--reader-primary);
    border: 2px solid var(--reader-surface);
    border-radius: 50%;
    cursor: pointer;
    box-shadow: 0 2px 6px rgba(0, 0, 0, 0.2);
    transition: transform 0.15s ease;
}
.reader-scrubber::-webkit-slider-thumb:hover {
    transform: scale(1.25);
}

/* Slide-out Drawers */
.reader-drawer {
    position: fixed;
    top: 54px;
    bottom: 38px;
    width: 380px;
    max-width: 90vw;
    background-color: var(--reader-surface);
    border-right: 1px solid var(--reader-border);
    z-index: 90;
    box-shadow: 6px 0 30px rgba(0, 0, 0, 0.12);
    transform: translateX(-100%);
    transition: transform 0.3s cubic-bezier(0.16, 1, 0.3, 1);
    display: flex;
    flex-direction: column;
}
.reader-drawer.open {
    transform: translateX(0);
}
.reader-drawer-right {
    right: 0;
    left: auto;
    border-left: 1px solid var(--reader-border);
    border-right: none;
    box-shadow: -6px 0 30px rgba(0, 0, 0, 0.12);
    transform: translateX(100%);
}
.reader-drawer-right.open {
    transform: translateX(0);
}

.drawer-header {
    padding: 0.85rem 1.1rem;
    border-bottom: 1px solid var(--reader-border);
    display: flex;
    align-items: center;
    justify-content: space-between;
    font-weight: 700;
    font-size: 0.92rem;
    color: var(--reader-text);
}
.drawer-body {
    flex: 1;
    overflow-y: auto;
    padding: 0.85rem;
}
.drawer-list {
    list-style: none;
    padding: 0;
    margin: 0;
}
.drawer-item {
    padding: 0.65rem 0.85rem;
    border-radius: 8px;
    margin-bottom: 0.3rem;
    font-size: 0.86rem;
    cursor: pointer;
    transition: all 0.15s ease;
    color: var(--reader-text);
    display: block;
    text-decoration: none;
    border: 1px solid transparent;
}
.drawer-item:hover {
    background-color: var(--reader-surface-subtle);
    color: var(--reader-primary);
    border-color: var(--reader-border);
}
.drawer-item.active {
    background-color: var(--reader-primary-light);
    color: var(--reader-primary);
    font-weight: 600;
    border-color: var(--reader-primary);
}

/* Settings Drawer Theme Option Cards */
.theme-grid {
    display: grid;
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
}
.theme-card-option {
    border: 1.5px solid var(--reader-border);
    border-radius: 10px;
    padding: 9px 11px;
    cursor: pointer;
    transition: all 0.2s ease;
    display: flex;
    align-items: center;
    gap: 9px;
    font-weight: 600;
    font-size: 0.82rem;
    background: var(--reader-surface);
    color: var(--reader-text);
    user-select: none;
}
.theme-card-option:hover {
    border-color: var(--reader-primary);
    transform: translateY(-1px);
}
.theme-card-option.active {
    border-color: var(--reader-primary);
    background-color: var(--reader-primary-light);
    color: var(--reader-primary);
    box-shadow: 0 2px 6px var(--reader-primary-light);
}
.theme-dot {
    width: 18px;
    height: 18px;
    border-radius: 50%;
    border: 1px solid rgba(0, 0, 0, 0.15);
    display: inline-block;
    flex-shrink: 0;
}

/* Floating Highlight Action Toolbar */
#highlight-toolbar {
    position: absolute;
    display: none;
    background: var(--reader-surface);
    border-radius: 28px;
    box-shadow: 0 8px 24px rgba(0, 0, 0, 0.22);
    padding: 5px 10px;
    z-index: 999;
    align-items: center;
    gap: 7px;
    border: 1px solid var(--reader-border);
    backdrop-filter: blur(10px);
}
.hl-color-btn {
    width: 22px;
    height: 22px;
    border-radius: 50%;
    cursor: pointer;
    border: 2px solid #ffffff;
    box-shadow: 0 1px 4px rgba(0, 0, 0, 0.2);
    transition: transform 0.15s ease;
}
.hl-color-btn:hover {
    transform: scale(1.3);
}

/* Loading Spinner Overlay */
#reader-loader {
    position: absolute;
    top: 0;
    left: 0;
    width: 100%;
    height: 100%;
    background: var(--reader-surface);
    display: flex;
    flex-direction: column;
    align-items: center;
    justify-content: center;
    z-index: 80;
    transition: opacity 0.3s ease;
}

/* DRM Toast */
#drm-toast {
    position: fixed;
    bottom: 54px;
    left: 50%;
    transform: translateX(-50%);
    background: rgba(15, 23, 42, 0.94);
    color: #ffffff;
    padding: 8px 20px;
    border-radius: 24px;
    font-size: 0.82rem;
    font-weight: 500;
    z-index: 9999;
    display: none;
    box-shadow: 0 6px 20px rgba(0, 0, 0, 0.35);
    backdrop-filter: blur(6px);
    border: 1px solid rgba(255, 255, 255, 0.15);
    white-space: nowrap;
}

/* Modal Customizations */
.reader-modal .modal-content {
    background-color: var(--reader-surface);
    color: var(--reader-text);
    border: 1px solid var(--reader-border);
    border-radius: 16px;
    box-shadow: var(--reader-shadow-lg);
}
.reader-modal .modal-header {
    border-bottom: 1px solid var(--reader-border);
}
.reader-modal .modal-footer {
    border-top: 1px solid var(--reader-border);
}

/* PDF Mode Viewport */
.reader-pdf-container {
    width: 100%;
    height: 100%;
    max-width: 1100px;
    margin: 0 auto;
    background: var(--reader-surface);
    border-radius: 10px;
    overflow: hidden;
    position: relative;
    display: flex;
    flex-direction: column;
    box-shadow: var(--reader-shadow-lg);
    border: 1px solid var(--reader-border);
}
.pdf-viewport {
    flex: 1;
    overflow-y: auto;
    display: flex;
    justify-content: center;
    padding: 20px 10px;
}
#pdfCanvas {
    max-width: 100%;
    box-shadow: 0 4px 20px rgba(0, 0, 0, 0.12);
    border-radius: 4px;
}

/* Print Protection */
@media print {
    body {
        display: none !important;
    }
}