/* ==========================================================================
   MODERN 3D FLIPBOOK - DESIGN SYSTEM & STYLESHEET
   Aesthetics: Modern Glassmorphism, Luxury Dark Studio, Responsive 3D Physics
   ========================================================================== */

@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700&family=Outfit:wght@400;500;600;700;800&family=JetBrains+Mono:wght@400;500&display=swap');

/* Root Theme Variables */
:root {
  --font-display: 'Outfit', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-body: 'Inter', -apple-system, BlinkMacSystemFont, sans-serif;
  --font-mono: 'JetBrains Mono', monospace;

  /* Theme: Dark Studio (Default) */
  --bg-primary: #070a12;
  --bg-secondary: #0e1424;
  --bg-card: rgba(20, 29, 48, 0.7);
  --bg-glass: rgba(14, 20, 36, 0.82);
  --glass-border: rgba(255, 255, 255, 0.1);
  --glass-border-hover: rgba(56, 189, 248, 0.4);
  --glass-shadow: 0 20px 40px -15px rgba(0, 0, 0, 0.6), 0 0 0 1px rgba(255, 255, 255, 0.08);

  --accent-primary: #38bdf8;
  --accent-secondary: #818cf8;
  --accent-gradient: linear-gradient(135deg, #38bdf8 0%, #6366f1 50%, #a855f7 100%);
  --accent-glow: rgba(56, 189, 248, 0.25);

  --text-primary: #f8fafc;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;

  --book-shadow: 0 35px 60px -15px rgba(0, 0, 0, 0.85), 0 10px 25px rgba(0, 0, 0, 0.5);
  --book-spine: linear-gradient(to right, rgba(0,0,0,0.45) 0%, rgba(0,0,0,0.1) 40%, rgba(255,255,255,0.05) 50%, rgba(0,0,0,0.1) 60%, rgba(0,0,0,0.45) 100%);
  --book-page-border: 1px solid rgba(255, 255, 255, 0.12);

  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-full: 9999px;

  --transition-fast: 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  --transition-normal: 0.3s cubic-bezier(0.16, 1, 0.3, 1);
}

/* Theme: Midnight Cosmic */
body.theme-midnight {
  --bg-primary: #050510;
  --bg-secondary: #0c0d24;
  --bg-card: rgba(22, 22, 56, 0.7);
  --bg-glass: rgba(14, 15, 42, 0.85);
  --accent-primary: #a855f7;
  --accent-secondary: #ec4899;
  --accent-gradient: linear-gradient(135deg, #a855f7 0%, #ec4899 100%);
  --accent-glow: rgba(168, 85, 247, 0.3);
}

/* Theme: Crisp Light Minimal */
body.theme-light {
  --bg-primary: #eceff5;
  --bg-secondary: #f8fafc;
  --bg-card: rgba(255, 255, 255, 0.88);
  --bg-glass: rgba(255, 255, 255, 0.92);
  --glass-border: rgba(0, 0, 0, 0.08);
  --glass-border-hover: rgba(14, 165, 233, 0.5);
  --glass-shadow: 0 15px 35px -10px rgba(0, 0, 0, 0.12), 0 0 0 1px rgba(0, 0, 0, 0.05);
  --accent-primary: #0284c7;
  --accent-secondary: #6366f1;
  --accent-gradient: linear-gradient(135deg, #0284c7 0%, #4f46e5 100%);
  --accent-glow: rgba(2, 132, 199, 0.18);
  --text-primary: #0f172a;
  --text-secondary: #475569;
  --text-muted: #94a3b8;
  --book-shadow: 0 25px 50px -12px rgba(15, 23, 42, 0.25), 0 8px 16px rgba(15, 23, 42, 0.15);
  --book-page-border: 1px solid rgba(0, 0, 0, 0.1);
}

/* Theme: Executive Warm Sepia */
body.theme-warm {
  --bg-primary: #181412;
  --bg-secondary: #241d1a;
  --bg-card: rgba(48, 38, 34, 0.7);
  --bg-glass: rgba(36, 28, 24, 0.88);
  --accent-primary: #f59e0b;
  --accent-secondary: #d97706;
  --accent-gradient: linear-gradient(135deg, #f59e0b 0%, #b45309 100%);
  --accent-glow: rgba(245, 158, 11, 0.25);
  --text-primary: #fef3c7;
  --text-secondary: #d4bda8;
  --text-muted: #8c7667;
  --book-shadow: 0 30px 60px -15px rgba(0, 0, 0, 0.8), 0 0 40px rgba(245, 158, 11, 0.06);
}

/* Base Reset */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: var(--font-body);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  user-select: none;
  -webkit-user-select: none;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* Dynamic Ambient Glow Orbs */
.ambient-lighting {
  position: fixed;
  inset: 0;
  pointer-events: none;
  z-index: 0;
  overflow: hidden;
}

.ambient-orb {
  position: absolute;
  border-radius: 50%;
  filter: blur(120px);
  opacity: 0.35;
  transition: all 1.2s ease;
  animation: orbFloat 18s ease-in-out infinite alternate;
}

.orb-1 {
  width: 550px;
  height: 550px;
  top: -150px;
  left: 20%;
  background: radial-gradient(circle, var(--accent-primary) 0%, transparent 70%);
}

.orb-2 {
  width: 600px;
  height: 600px;
  bottom: -200px;
  right: 15%;
  background: radial-gradient(circle, var(--accent-secondary) 0%, transparent 70%);
  animation-duration: 22s;
  animation-delay: -5s;
}

@keyframes orbFloat {
  0% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(40px, 30px) scale(1.08); }
  100% { transform: translate(-30px, -20px) scale(0.95); }
}

/* Application Wrapper */
.app-container {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  z-index: 1;
}

/* ==========================================================================
   TOP BAR (HEADER)
   ========================================================================== */
.top-bar {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  height: 64px;
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--glass-border);
  z-index: 20;
  transition: all var(--transition-normal);
}

.top-bar-left {
  display: flex;
  align-items: center;
  gap: 14px;
  min-width: 0;
}

.brand-badge {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
}

.brand-logo-icon {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--accent-gradient);
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 4px 14px var(--accent-glow);
  color: #fff;
  flex-shrink: 0;
}

.brand-title-group {
  display: flex;
  flex-direction: column;
  min-width: 0;
}

.book-main-title {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  letter-spacing: -0.01em;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 380px;
}

.book-subtitle-tag {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.75rem;
  color: var(--text-secondary);
}

.tag-pill {
  display: inline-flex;
  align-items: center;
  padding: 2px 7px;
  background: rgba(56, 189, 248, 0.12);
  color: var(--accent-primary);
  border-radius: var(--radius-full);
  font-size: 0.68rem;
  font-weight: 600;
  border: 1px solid rgba(56, 189, 248, 0.25);
}

/* Center Status (Page Counter) */
.top-bar-center {
  display: flex;
  align-items: center;
  gap: 12px;
}

.page-indicator-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 14px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  font-size: 0.82rem;
  font-family: var(--font-mono);
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.page-indicator-pill:hover {
  background: rgba(255, 255, 255, 0.09);
  border-color: var(--glass-border-hover);
}

.page-indicator-pill strong {
  color: var(--accent-primary);
}

/* Top Bar Right Actions */
.top-bar-right {
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-icon {
  position: relative;
  width: 40px;
  height: 40px;
  border-radius: var(--radius-md);
  background: transparent;
  border: 1px solid transparent;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-icon:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
  border-color: var(--glass-border);
  transform: translateY(-1px);
}

.btn-icon:active {
  transform: translateY(1px);
}

.btn-icon.active {
  background: var(--accent-gradient);
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 14px var(--accent-glow);
}

.btn-pill {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 8px 16px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  font-family: var(--font-body);
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-primary);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.btn-pill:hover {
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--glass-border-hover);
  color: var(--accent-primary);
}

.btn-pill-primary {
  background: var(--accent-gradient);
  border-color: transparent;
  color: #fff;
  box-shadow: 0 4px 14px var(--accent-glow);
}

.btn-pill-primary:hover {
  filter: brightness(1.1);
  color: #fff;
}

/* ==========================================================================
   BOOK STAGE (MAIN DISPLAY AREA)
   ========================================================================== */
.book-stage {
  position: relative;
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 16px 60px 100px 60px;
  perspective: 2500px;
}

.book-zoom-viewport {
  position: relative;
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  transform-origin: center center;
}

.book-zoom-viewport.is-panning {
  cursor: grab;
}

.book-zoom-viewport.is-panning:active {
  cursor: grabbing;
}

/* StPageFlip Container */
#flipbook {
  position: relative;
  margin: auto;
  box-shadow: var(--book-shadow);
  border-radius: 4px;
  transition: box-shadow var(--transition-normal);
}

/* Realistic Book Center Spine Effect */
.book-spine-crease {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 50%;
  width: 44px;
  transform: translateX(-50%);
  background: var(--book-spine);
  pointer-events: none;
  z-index: 10;
  opacity: 0.75;
  transition: opacity 0.3s ease;
}

/* Page Items */
.flipbook-page {
  position: relative;
  background-color: #ffffff;
  overflow: hidden;
  box-shadow: inset 0 0 15px rgba(0, 0, 0, 0.08);
}

.flipbook-page img {
  width: 100%;
  height: 100%;
  object-fit: fill;
  display: block;
  pointer-events: none;
}

.flipbook-page.--hard {
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.5);
}

/* Floating Navigation Arrows (Side) */
.nav-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 52px;
  height: 52px;
  border-radius: var(--radius-full);
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  z-index: 15;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.4);
  transition: all var(--transition-fast);
}

.nav-arrow:hover {
  background: var(--accent-gradient);
  border-color: transparent;
  color: #fff;
  transform: translateY(-50%) scale(1.1);
  box-shadow: 0 10px 28px var(--accent-glow);
}

.nav-arrow:active {
  transform: translateY(-50%) scale(0.95);
}

.nav-arrow.disabled {
  opacity: 0.3;
  pointer-events: none;
}

.nav-arrow-prev {
  left: 18px;
}

.nav-arrow-next {
  right: 18px;
}

/* Page Corner Curl Guides */
.corner-hint {
  position: absolute;
  width: 48px;
  height: 48px;
  pointer-events: none;
  z-index: 12;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.corner-hint-bottom-right {
  bottom: 0;
  right: 0;
  background: linear-gradient(135deg, transparent 50%, rgba(56, 189, 248, 0.3) 100%);
  border-bottom-right-radius: 4px;
}

.corner-hint-bottom-left {
  bottom: 0;
  left: 0;
  background: linear-gradient(225deg, transparent 50%, rgba(56, 189, 248, 0.3) 100%);
  border-bottom-left-radius: 4px;
}

#flipbook:hover .corner-hint {
  opacity: 1;
}

/* ==========================================================================
   BOTTOM FLOATING DOCK (TOOLBAR)
   ========================================================================== */
.bottom-dock-container {
  position: fixed;
  bottom: 20px;
  left: 50%;
  transform: translateX(-50%);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  z-index: 30;
  width: auto;
  max-width: 95vw;
}

/* Live Page Scrubber Slider */
.dock-scrubber-bar {
  position: relative;
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 8px 18px;
  background: var(--bg-glass);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  box-shadow: var(--glass-shadow);
  width: 420px;
  max-width: 90vw;
  transition: all var(--transition-fast);
}

.dock-scrubber-bar:hover {
  border-color: var(--glass-border-hover);
}

.scrubber-slider {
  position: relative;
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 3px;
  outline: none;
  cursor: pointer;
}

.scrubber-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-primary);
  border: 2px solid #fff;
  box-shadow: 0 0 10px var(--accent-glow);
  cursor: pointer;
  transition: transform 0.15s ease, background-color 0.15s ease;
}

.scrubber-slider::-webkit-slider-thumb:hover {
  transform: scale(1.25);
  background: #fff;
  border-color: var(--accent-primary);
}

.scrubber-label {
  font-family: var(--font-mono);
  font-size: 0.78rem;
  color: var(--text-secondary);
  white-space: nowrap;
  min-width: 46px;
  text-align: center;
}

/* Floating Thumbnail Hover Preview Box */
.scrubber-preview-popup {
  position: absolute;
  bottom: calc(100% + 14px);
  left: 50%;
  transform: translateX(-50%) translateY(8px);
  width: 140px;
  height: 195px;
  background: var(--bg-card);
  backdrop-filter: blur(16px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  box-shadow: var(--glass-shadow);
  padding: 6px;
  display: flex;
  flex-direction: column;
  align-items: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.2s ease, transform 0.2s ease;
  z-index: 50;
}

.scrubber-preview-popup.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.scrubber-preview-img {
  width: 100%;
  height: 155px;
  object-fit: cover;
  border-radius: 6px;
  background: #fff;
}

.scrubber-preview-text {
  margin-top: 6px;
  font-size: 0.72rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* Main Floating Island Dock */
.dock-island {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 6px 12px;
  background: var(--bg-glass);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-full);
  box-shadow: var(--glass-shadow);
  transition: all var(--transition-normal);
}

.dock-island:hover {
  border-color: var(--glass-border-hover);
  box-shadow: 0 25px 50px -12px rgba(0, 0, 0, 0.7), 0 0 20px var(--accent-glow);
}

.dock-divider {
  width: 1px;
  height: 24px;
  background: rgba(255, 255, 255, 0.12);
  margin: 0 4px;
}

/* Tooltip implementation */
[data-tooltip] {
  position: relative;
}

[data-tooltip]::after {
  content: attr(data-tooltip);
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%) scale(0.9);
  padding: 5px 10px;
  background: rgba(15, 23, 42, 0.95);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-sm);
  color: #fff;
  font-family: var(--font-body);
  font-size: 0.72rem;
  font-weight: 500;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: all 0.18s cubic-bezier(0.16, 1, 0.3, 1);
  box-shadow: 0 8px 16px rgba(0, 0, 0, 0.4);
  z-index: 100;
}

[data-tooltip]:hover::after {
  opacity: 1;
  transform: translateX(-50%) scale(1);
}

/* Auto-play badge progress */
.autoplay-indicator {
  position: absolute;
  inset: 2px;
  border-radius: 50%;
  border: 2px solid transparent;
  border-top-color: var(--accent-primary);
  animation: spinRing 4s linear infinite;
  display: none;
}

.autoplay-active .autoplay-indicator {
  display: block;
}

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

/* ==========================================================================
   SLIDE-UP THUMBNAIL DRAWER
   ========================================================================== */
.drawer-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: 40;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.3s ease;
}

.drawer-backdrop.active {
  opacity: 1;
  pointer-events: auto;
}

.thumbnails-drawer {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: 240px;
  background: var(--bg-card);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  border-top: 1px solid var(--glass-border);
  z-index: 45;
  transform: translateY(100%);
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
}

.thumbnails-drawer.open {
  transform: translateY(0);
}

.drawer-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 24px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.drawer-title {
  font-family: var(--font-display);
  font-size: 0.95rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 8px;
}

.thumbnails-scroll {
  flex: 1;
  display: flex;
  align-items: center;
  gap: 16px;
  padding: 12px 24px;
  overflow-x: auto;
  overflow-y: hidden;
  scroll-behavior: smooth;
}

.thumbnail-item {
  position: relative;
  flex-shrink: 0;
  width: 105px;
  height: 145px;
  background: #fff;
  border-radius: 8px;
  overflow: hidden;
  cursor: pointer;
  border: 2px solid transparent;
  transition: all var(--transition-fast);
  box-shadow: 0 6px 16px rgba(0, 0, 0, 0.35);
}

.thumbnail-item:hover {
  transform: translateY(-6px) scale(1.04);
  border-color: var(--accent-primary);
  box-shadow: 0 12px 24px var(--accent-glow);
}

.thumbnail-item.active {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 2px var(--accent-primary), 0 10px 20px var(--accent-glow);
}

.thumbnail-item img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.thumbnail-badge {
  position: absolute;
  bottom: 6px;
  right: 6px;
  padding: 2px 6px;
  background: rgba(15, 23, 42, 0.85);
  color: #fff;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  font-weight: 600;
  border-radius: 4px;
}

/* ==========================================================================
   SIDEBAR TABLE OF CONTENTS (DAFTAR ISI)
   ========================================================================== */
.sidebar-drawer {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 380px;
  max-width: 85vw;
  background: var(--bg-glass);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  border-right: 1px solid var(--glass-border);
  z-index: 45;
  transform: translateX(-100%);
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
  display: flex;
  flex-direction: column;
}

.sidebar-drawer.open {
  transform: translateX(0);
}

.toc-search-box {
  padding: 14px 20px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.toc-search-input {
  width: 100%;
  padding: 10px 14px 10px 38px;
  background: rgba(255, 255, 255, 0.06);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  color: var(--text-primary);
  font-family: var(--font-body);
  font-size: 0.85rem;
  outline: none;
  transition: border-color 0.2s ease;
}

.toc-search-input:focus {
  border-color: var(--accent-primary);
  background: rgba(255, 255, 255, 0.09);
}

.toc-search-wrap {
  position: relative;
}

.toc-search-icon {
  position: absolute;
  left: 12px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  pointer-events: none;
}

.toc-list {
  flex: 1;
  overflow-y: auto;
  padding: 12px 14px;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.toc-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  background: transparent;
  border-radius: var(--radius-md);
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  border: 1px solid transparent;
}

.toc-item:hover {
  background: rgba(255, 255, 255, 0.07);
  color: var(--text-primary);
  border-color: var(--glass-border);
  transform: translateX(3px);
}

.toc-item.active {
  background: rgba(56, 189, 248, 0.12);
  border-color: rgba(56, 189, 248, 0.3);
  color: var(--accent-primary);
  font-weight: 600;
}

.toc-item-left {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 0.88rem;
  min-width: 0;
}

.toc-item-title {
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.toc-item-page {
  font-family: var(--font-mono);
  font-size: 0.75rem;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-muted);
  flex-shrink: 0;
}

/* ==========================================================================
   MODALS (SEARCH, SHARE, SETTINGS, BOOKMARKS)
   ========================================================================== */
.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(10px);
  z-index: 60;
  display: flex;
  align-items: center;
  justify-content: center;
  padding: 20px;
  opacity: 0;
  pointer-events: none;
  transition: opacity 0.25s ease;
}

.modal-overlay.active {
  opacity: 1;
  pointer-events: auto;
}

.modal-box {
  width: 100%;
  max-width: 500px;
  background: var(--bg-card);
  backdrop-filter: blur(30px);
  -webkit-backdrop-filter: blur(30px);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-lg);
  box-shadow: 0 25px 60px -15px rgba(0, 0, 0, 0.8), 0 0 0 1px rgba(255, 255, 255, 0.1);
  overflow: hidden;
  transform: scale(0.94) translateY(10px);
  transition: transform 0.25s cubic-bezier(0.16, 1, 0.3, 1);
}

.modal-overlay.active .modal-box {
  transform: scale(1) translateY(0);
}

.modal-box-large {
  max-width: 880px;
}

/* ==========================================================================
   LIBRARY MODAL (DATABASE PDF CARDS & DROPZONE)
   ========================================================================== */
.library-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(240px, 1fr));
  gap: 18px;
  margin-top: 10px;
}

.book-card {
  position: relative;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: all var(--transition-fast);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.2);
}

.book-card:hover {
  border-color: var(--accent-primary);
  transform: translateY(-4px);
  box-shadow: 0 12px 28px rgba(0, 0, 0, 0.4), 0 0 15px var(--accent-glow);
}

.book-card.is-active-book {
  border-color: var(--accent-primary);
  box-shadow: 0 0 0 2px var(--accent-primary), 0 10px 25px var(--accent-glow);
}

.book-card-cover-wrap {
  position: relative;
  width: 100%;
  height: 180px;
  background: #0f172a;
  overflow: hidden;
  display: flex;
  align-items: center;
  justify-content: center;
}

.book-card-cover-img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transition: transform 0.3s ease;
}

.book-card:hover .book-card-cover-img {
  transform: scale(1.05);
}

.book-card-badge {
  position: absolute;
  top: 10px;
  left: 10px;
  padding: 3px 8px;
  border-radius: var(--radius-full);
  font-size: 0.7rem;
  font-weight: 600;
  backdrop-filter: blur(12px);
  z-index: 2;
}

.badge-default {
  background: rgba(56, 189, 248, 0.25);
  color: var(--accent-primary);
  border: 1px solid rgba(56, 189, 248, 0.5);
}

.badge-custom {
  background: rgba(168, 85, 247, 0.25);
  color: #c084fc;
  border: 1px solid rgba(168, 85, 247, 0.5);
}

.book-card-pages-pill {
  position: absolute;
  bottom: 8px;
  right: 8px;
  padding: 2px 7px;
  background: rgba(15, 23, 42, 0.85);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: 0.68rem;
  color: #fff;
  z-index: 2;
}

.book-card-body {
  padding: 14px;
  flex: 1;
  display: flex;
  flex-direction: column;
}

.book-card-title {
  font-family: var(--font-display);
  font-size: 0.92rem;
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: 6px;
  line-height: 1.3;
  display: -webkit-box;
  -webkit-line-clamp: 2;
  -webkit-box-orient: vertical;
  overflow: hidden;
}

.book-card-meta {
  font-size: 0.74rem;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-top: auto;
  padding-top: 8px;
  border-top: 1px solid rgba(255, 255, 255, 0.06);
}

.book-card-actions {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 14px 14px 14px;
}

.btn-card-open {
  flex: 1;
  padding: 8px 12px;
  background: var(--accent-gradient);
  border: none;
  border-radius: var(--radius-sm);
  color: #fff;
  font-size: 0.8rem;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  transition: all var(--transition-fast);
}

.btn-card-open:hover {
  filter: brightness(1.1);
  box-shadow: 0 4px 12px var(--accent-glow);
}

.btn-card-delete {
  padding: 8px 10px;
  background: rgba(239, 68, 68, 0.1);
  border: 1px solid rgba(239, 68, 68, 0.25);
  border-radius: var(--radius-sm);
  color: #ef4444;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: all var(--transition-fast);
}

.btn-card-delete:hover {
  background: #ef4444;
  color: #fff;
  border-color: transparent;
  box-shadow: 0 4px 12px rgba(239, 68, 68, 0.35);
}

/* Upload card in library */
.library-upload-card {
  border: 2px dashed rgba(255, 255, 255, 0.2);
  border-radius: var(--radius-md);
  padding: 24px 16px;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  text-align: center;
  cursor: pointer;
  background: rgba(255, 255, 255, 0.02);
  transition: all var(--transition-fast);
  min-height: 260px;
}

.library-upload-card:hover {
  border-color: var(--accent-primary);
  background: rgba(56, 189, 248, 0.06);
  transform: translateY(-4px);
}

.library-upload-icon {
  width: 48px;
  height: 48px;
  border-radius: 50%;
  background: rgba(56, 189, 248, 0.15);
  color: var(--accent-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 12px;
}


.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 18px 24px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
}

.modal-title {
  font-family: var(--font-display);
  font-size: 1.1rem;
  font-weight: 700;
  display: flex;
  align-items: center;
  gap: 10px;
}

.modal-body {
  padding: 22px 24px;
  max-height: 65vh;
  overflow-y: auto;
}

.modal-footer {
  display: flex;
  align-items: center;
  justify-content: flex-end;
  gap: 10px;
  padding: 16px 24px;
  border-top: 1px solid rgba(255, 255, 255, 0.08);
}

/* Theme selector grid */
.theme-options-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 12px;
  margin-top: 10px;
}

.theme-card {
  padding: 14px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 12px;
  transition: all var(--transition-fast);
}

.theme-card:hover {
  background: rgba(255, 255, 255, 0.08);
  border-color: var(--accent-primary);
  transform: translateY(-2px);
}

.theme-card.active {
  border-color: var(--accent-primary);
  background: rgba(56, 189, 248, 0.12);
  box-shadow: 0 0 16px var(--accent-glow);
}

.theme-preview-dot {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.2);
}

.theme-name {
  font-size: 0.88rem;
  font-weight: 600;
  color: var(--text-primary);
}

/* Form controls inside settings */
.settings-group {
  margin-bottom: 20px;
}

.settings-label {
  display: block;
  font-size: 0.82rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 8px;
}

.range-wrap {
  display: flex;
  align-items: center;
  gap: 14px;
}

.range-input {
  flex: 1;
  -webkit-appearance: none;
  appearance: none;
  height: 6px;
  background: rgba(255, 255, 255, 0.15);
  border-radius: 3px;
  outline: none;
}

.range-input::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 18px;
  height: 18px;
  border-radius: 50%;
  background: var(--accent-primary);
  cursor: pointer;
}

/* Search results list */
.search-results-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 14px;
}

.search-result-card {
  padding: 12px 16px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--glass-border);
  border-radius: var(--radius-md);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.search-result-card:hover {
  background: rgba(56, 189, 248, 0.1);
  border-color: var(--accent-primary);
  transform: translateX(4px);
}

.search-result-card-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 4px;
  font-size: 0.84rem;
  font-weight: 600;
  color: var(--accent-primary);
}

.search-result-snippet {
  font-size: 0.78rem;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* QR Code Display */
.qr-code-container {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 18px;
  background: #ffffff;
  border-radius: var(--radius-md);
  margin: 14px auto;
  width: 180px;
  height: 180px;
  box-shadow: 0 10px 25px rgba(0, 0, 0, 0.2);
}

/* ==========================================================================
   LOADING & PROGRESS OVERLAY
   ========================================================================== */
.loader-overlay {
  position: fixed;
  inset: 0;
  background: var(--bg-primary);
  z-index: 999;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 20px;
  transition: opacity 0.5s ease, visibility 0.5s ease;
}

.loader-overlay.hidden {
  opacity: 0;
  visibility: hidden;
  pointer-events: none;
}

.loader-spinner {
  width: 54px;
  height: 54px;
  border: 3px solid rgba(56, 189, 248, 0.15);
  border-top-color: var(--accent-primary);
  border-radius: 50%;
  animation: spin 0.8s linear infinite;
}

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

.loader-title {
  font-family: var(--font-display);
  font-size: 1.25rem;
  font-weight: 700;
  color: var(--text-primary);
}

.loader-subtitle {
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.loader-progress-bar {
  width: 280px;
  height: 6px;
  background: rgba(255, 255, 255, 0.1);
  border-radius: 3px;
  overflow: hidden;
}

.loader-progress-fill {
  height: 100%;
  width: 0%;
  background: var(--accent-gradient);
  transition: width 0.2s ease;
}

/* Hidden file input */
#pdfFileInput {
  display: none;
}

/* ==========================================================================
   RESPONSIVE BREAKPOINTS
   ========================================================================== */
@media (max-width: 900px) {
  .book-stage {
    padding: 10px 10px 90px 10px;
  }
  .nav-arrow {
    width: 42px;
    height: 42px;
  }
  .nav-arrow-prev { left: 8px; }
  .nav-arrow-next { right: 8px; }
  .book-main-title { max-width: 220px; }
  .btn-pill span { display: none; }
  .btn-pill { padding: 8px; }
  .dock-scrubber-bar { width: 300px; }
}

@media (max-width: 600px) {
  .top-bar { padding: 8px 14px; height: 56px; }
  .book-subtitle-tag { display: none; }
  .book-main-title { font-size: 0.85rem; max-width: 160px; }
  .bottom-dock-container { bottom: 12px; }
  .dock-scrubber-bar { display: none; }
  .dock-island { padding: 4px 8px; }
  .btn-icon { width: 34px; height: 34px; }
}