/* ==========================================================================
   THE SIMA JOURNEY — INTERACTIVE 3D FLIPBOOK DESIGN SYSTEM
   Curated Typography, Obsidian Dark & Teak Themes, Glassmorphism & 3D Realism
   ========================================================================== */

/* --- Root Color Tokens & Themes --- */
:root {
  /* Default Theme: Executive Obsidian */
  --bg-primary: #07090E;
  --bg-secondary: #0F1420;
  --bg-tertiary: #182032;
  --bg-glass: rgba(15, 20, 32, 0.78);
  --bg-glass-strong: rgba(15, 20, 32, 0.92);
  --border-glass: rgba(56, 189, 248, 0.22);
  --border-subtle: rgba(255, 255, 255, 0.08);

  --text-primary: #F8FAFC;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;

  --accent-gold: #38BDF8;
  --accent-gold-glow: rgba(56, 189, 248, 0.38);
  --accent-amber: #0284C7;
  --accent-cyan: #7DD3FC;
  --accent-cyan-glow: rgba(125, 211, 252, 0.35);

  --desk-surface: radial-gradient(circle at 50% 40%, #0d1b2e 0%, #07090E 80%);
  --book-shadow: 0 25px 60px -15px rgba(0, 0, 0, 0.8), 0 0 40px rgba(56, 189, 248, 0.1);
  --page-shadow: 0 10px 30px rgba(0, 0, 0, 0.5);

  --font-serif: 'Cinzel', serif, Georgia;
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', Roboto, sans-serif;
  --font-display: 'Outfit', sans-serif;

  --nav-height: 64px;
  --dock-height: 84px;
  --transition-fast: 0.2s cubic-bezier(0.4, 0, 0.2, 1);
  --transition-normal: 0.35s cubic-bezier(0.16, 1, 0.3, 1);

  /* iOS / Mobile Safe Area Insets */
  --safe-top: env(safe-area-inset-top, 0px);
  --safe-bottom: env(safe-area-inset-bottom, 0px);
  --safe-left: env(safe-area-inset-left, 0px);
  --safe-right: env(safe-area-inset-right, 0px);
}

/* Theme 2: Teak & Parchment (Warm Library) */
[data-theme="teak"] {
  --bg-primary: #1C130E;
  --bg-secondary: #2B1D15;
  --bg-tertiary: #3D2B1F;
  --bg-glass: rgba(43, 29, 21, 0.85);
  --bg-glass-strong: rgba(43, 29, 21, 0.95);
  --border-glass: rgba(217, 119, 6, 0.3);
  --border-subtle: rgba(255, 255, 255, 0.1);

  --text-primary: #FAF5EE;
  --text-secondary: #D4C3B3;
  --text-muted: #9E8976;

  --accent-gold: #F59E0B;
  --accent-gold-glow: rgba(245, 158, 11, 0.3);
  --accent-amber: #B45309;
  --accent-cyan: #38BDF8;

  --desk-surface: radial-gradient(circle at 50% 35%, #382418 0%, #170E0A 85%);
  --book-shadow: 0 25px 55px -12px rgba(0, 0, 0, 0.9), 0 0 50px rgba(180, 83, 9, 0.15);
}

/* Theme 3: Gallery Editorial (Clean Contemporary White) */
[data-theme="editorial"] {
  --bg-primary: #F3F4F6;
  --bg-secondary: #FFFFFF;
  --bg-tertiary: #E5E7EB;
  --bg-glass: rgba(255, 255, 255, 0.88);
  --bg-glass-strong: rgba(255, 255, 255, 0.96);
  --border-glass: rgba(0, 0, 0, 0.12);
  --border-subtle: rgba(0, 0, 0, 0.08);

  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;

  --accent-gold: #D97706;
  --accent-gold-glow: rgba(217, 119, 6, 0.2);
  --accent-amber: #92400E;
  --accent-cyan: #0284C7;

  --desk-surface: radial-gradient(circle at 50% 40%, #E2E8F0 0%, #CBD5E1 90%);
  --book-shadow: 0 20px 45px -10px rgba(0, 0, 0, 0.18), 0 0 25px rgba(0, 0, 0, 0.08);
}

/* Theme 4: Cyber Grid (High-Tech Smart Grid) */
[data-theme="cyber"] {
  --bg-primary: #020712;
  --bg-secondary: #061528;
  --bg-tertiary: #0B2440;
  --bg-glass: rgba(6, 21, 40, 0.82);
  --bg-glass-strong: rgba(6, 21, 40, 0.94);
  --border-glass: rgba(6, 182, 212, 0.35);
  --border-subtle: rgba(6, 182, 212, 0.15);

  --text-primary: #E0F2FE;
  --text-secondary: #7DD3FC;
  --text-muted: #38BDF8;

  --accent-gold: #38BDF8;
  --accent-gold-glow: rgba(56, 189, 248, 0.4);
  --accent-amber: #0284C7;
  --accent-cyan: #06B6D4;
  --accent-cyan-glow: rgba(6, 182, 212, 0.45);

  --desk-surface: radial-gradient(circle at 50% 40%, #08213D 0%, #01040A 85%);
  --book-shadow: 0 25px 65px -10px rgba(0, 0, 0, 0.85), 0 0 45px rgba(6, 182, 212, 0.2);
}

/* --- Base Resets & Global Rules --- */
*, *::before, *::after {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  font-family: var(--font-sans);
  background-color: var(--bg-primary);
  color: var(--text-primary);
  user-select: none;
}

button {
  font-family: inherit;
  cursor: pointer;
  border: none;
  background: none;
  color: inherit;
  outline: none;
}

button:focus-visible {
  outline: 2px solid var(--accent-gold);
  outline-offset: 2px;
}

.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* --- App Container Grid --- */
.app-container {
  display: flex;
  flex-direction: column;
  width: 100vw;
  width: 100%;
  height: 100vh;
  height: 100dvh;
  position: relative;
  overflow: hidden;
  background: var(--desk-surface);
}

/* --- Top Navigation Header --- */
.top-nav {
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  background: rgba(11, 15, 25, 0.72);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid rgba(255, 255, 255, 0.08);
  z-index: 50;
  box-shadow: 0 4px 20px rgba(0, 0, 0, 0.25);
  flex-shrink: 0;
}

.nav-left {
  display: flex;
  align-items: center;
}

/* Elegant Back Pill */
.nav-back-btn {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  padding: 7px 14px;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(255, 255, 255, 0.12);
  color: #D1D5DB;
  text-decoration: none;
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.2px;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-back-btn .icon {
  width: 16px;
  height: 16px;
  transition: transform 0.2s ease;
}

.nav-back-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: #FFFFFF;
  border-color: rgba(56, 189, 248, 0.4);
  box-shadow: 0 0 12px rgba(56, 189, 248, 0.25);
}

.nav-back-btn:hover .icon {
  transform: translateX(-2px);
}

/* Top Nav Action Group */
.nav-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

/* Base Action Button Style */
.action-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  height: 38px;
  padding: 0 16px;
  border-radius: 9999px;
  font-size: 13.5px;
  font-weight: 600;
  letter-spacing: 0.2px;
  cursor: pointer;
  text-decoration: none;
  transition: all 0.22s cubic-bezier(0.16, 1, 0.3, 1);
  white-space: nowrap;
  box-sizing: border-box;
}

.action-btn .icon {
  width: 17px;
  height: 17px;
  flex-shrink: 0;
}

/* Contents Button: Sleek Glass Pill with Light Blue Touch */
.action-btn-toc {
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(56, 189, 248, 0.35);
  color: #F3F4F6;
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
}

.action-btn-toc:hover {
  background: rgba(56, 189, 248, 0.14);
  border-color: #38BDF8;
  color: #FFFFFF;
  transform: translateY(-1px);
  box-shadow: 0 0 16px rgba(56, 189, 248, 0.25);
}

.action-btn-toc:active {
  transform: translateY(0);
}

/* Navigation Zoom Controls Group */
.nav-zoom-control {
  display: inline-flex;
  align-items: center;
  gap: 2px;
  height: 38px;
  padding: 3px 5px;
  border-radius: 9999px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid rgba(56, 189, 248, 0.35);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  box-shadow: 0 0 14px rgba(56, 189, 248, 0.12);
  transition: all 0.22s cubic-bezier(0.16, 1, 0.3, 1);
}

.nav-zoom-control:hover {
  border-color: rgba(56, 189, 248, 0.55);
  box-shadow: 0 0 18px rgba(56, 189, 248, 0.22);
}

.zoom-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: 32px;
  border: none;
  background: transparent;
  color: #E0F2FE;
  cursor: pointer;
  border-radius: 9999px;
  transition: all 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

.zoom-btn-out,
.zoom-btn-in {
  width: 32px;
  color: #38BDF8;
}

.zoom-btn-out .icon,
.zoom-btn-in .icon {
  width: 17px;
  height: 17px;
}

.zoom-btn-out:hover:not(:disabled),
.zoom-btn-in:hover:not(:disabled) {
  background: rgba(56, 189, 248, 0.18);
  color: #FFFFFF;
  transform: scale(1.08);
}

.zoom-btn-out:active:not(:disabled),
.zoom-btn-in:active:not(:disabled) {
  transform: scale(0.94);
}

.zoom-btn:disabled,
.zoom-btn.disabled {
  opacity: 0.32;
  cursor: not-allowed;
  pointer-events: none;
}

.zoom-btn-level {
  padding: 0 10px;
  font-family: 'Outfit', sans-serif;
  font-size: 13px;
  font-weight: 600;
  letter-spacing: 0.3px;
  color: #E0F2FE;
  min-width: 52px;
}

.zoom-btn-level:hover {
  background: rgba(56, 189, 248, 0.15);
  color: #38BDF8;
}

.zoom-btn-level.active {
  color: #38BDF8;
}

/* Buy on Amazon Button: Warm Amazon Accent */
.action-btn-amazon {
  background: rgba(255, 153, 0, 0.12);
  border: 1px solid rgba(255, 153, 0, 0.45);
  color: #FFB347;
  font-weight: 600;
  box-shadow: 0 2px 12px rgba(255, 153, 0, 0.2);
  position: relative;
  overflow: hidden;
  text-decoration: none;
}

.action-btn-amazon .icon {
  color: #FF9900;
}

.action-btn-amazon .amz-logo-img,
.action-btn-amazon img,
.action-btn-amazon .w-4 {
  width: 19px;
  height: 19px;
  min-width: 19px;
  min-height: 19px;
  max-width: 19px;
  max-height: 19px;
  object-fit: contain;
  background: #FFFFFF;
  border-radius: 50%;
  padding: 2px;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.35);
  flex-shrink: 0;
  display: block;
  transition: transform 0.2s ease;
}

.action-btn-amazon:hover {
  background: linear-gradient(135deg, #FF9900 0%, #E68A00 100%);
  color: #111111;
  border-color: #FFAA33;
  transform: translateY(-1.5px);
  box-shadow: 0 0 20px rgba(255, 153, 0, 0.55);
}

.action-btn-amazon:hover .icon {
  color: #111111;
}

.action-btn-amazon:hover .amz-logo-img,
.action-btn-amazon:hover img {
  transform: scale(1.08);
}

.action-btn-amazon:active {
  transform: translateY(0);
}

/* Download PDF Button: Eye-Catching Light Blue Gradient with Glow */
.action-btn-download {
  background: linear-gradient(135deg, #38BDF8 0%, #0284C7 100%);
  border: 1px solid #7DD3FC;
  color: #07090E;
  font-weight: 700;
  box-shadow: 0 2px 14px rgba(56, 189, 248, 0.35);
  position: relative;
  overflow: hidden;
}

.action-btn-download .icon {
  color: #07090E;
}

.action-btn-download:hover {
  background: linear-gradient(135deg, #7DD3FC 0%, #38BDF8 100%);
  color: #000000;
  border-color: #BAE6FD;
  transform: translateY(-1.5px);
  box-shadow: 0 0 22px rgba(56, 189, 248, 0.6);
}

.action-btn-download:active {
  transform: translateY(0);
}

/* Theme Dropdown */
.theme-dropdown {
  position: relative;
}

.theme-menu {
  position: absolute;
  top: calc(100% + 8px);
  right: 0;
  background: var(--bg-glass-strong);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--border-glass);
  border-radius: 12px;
  padding: 8px;
  display: none;
  flex-direction: column;
  gap: 4px;
  width: 180px;
  box-shadow: 0 10px 30px rgba(0, 0, 0, 0.4);
  z-index: 60;
}

.theme-menu.show {
  display: flex;
  animation: dropdownIn 0.2s cubic-bezier(0.16, 1, 0.3, 1);
}

@keyframes dropdownIn {
  from { opacity: 0; transform: translateY(-8px); }
  to { opacity: 1; transform: translateY(0); }
}

.theme-opt {
  display: flex;
  align-items: center;
  gap: 10px;
  padding: 8px 12px;
  border-radius: 8px;
  font-size: 13px;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
  text-align: left;
}

.theme-opt:hover {
  background: rgba(255, 255, 255, 0.08);
  color: var(--text-primary);
}

.theme-opt.active {
  color: var(--accent-gold);
  background: rgba(56, 189, 248, 0.12);
  font-weight: 600;
}

.swatch {
  width: 14px;
  height: 14px;
  border-radius: 50%;
  border: 2px solid rgba(255, 255, 255, 0.2);
}
.swatch-obsidian { background: #0B0F19; border-color: #38BDF8; }
.swatch-teak { background: #382418; border-color: #D97706; }
.swatch-editorial { background: #F3F4F6; border-color: #94A3B8; }
.swatch-cyber { background: #06B6D4; border-color: #38BDF8; }

/* --- Reading Stage --- */
.reading-stage {
  flex: 1 1 0%;
  min-height: 0;
  min-width: 0;
  width: 100%;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  padding: 8px 16px;
}

.stage-ambient-light {
  position: absolute;
  top: 10%;
  left: 50%;
  transform: translateX(-50%);
  width: 900px;
  height: 600px;
  background: radial-gradient(circle, var(--accent-gold-glow) 0%, transparent 70%);
  pointer-events: none;
  opacity: 0.25;
  filter: blur(80px);
}

.desk-mat {
  position: absolute;
  bottom: 5%;
  left: 50%;
  transform: translateX(-50%);
  width: min(85vw, 1100px);
  height: 100px;
  background: radial-gradient(ellipse at center, rgba(0, 0, 0, 0.5) 0%, transparent 70%);
  pointer-events: none;
  filter: blur(24px);
  z-index: 0;
}

/* Floating Navigation Arrows */
.floating-arrow {
  position: absolute;
  top: 50%;
  transform: translateY(-50%);
  width: 52px;
  height: 52px;
  border-radius: 50%;
  background: var(--bg-glass);
  backdrop-filter: blur(16px);
  -webkit-backdrop-filter: blur(16px);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 30;
  box-shadow: 0 8px 24px rgba(0, 0, 0, 0.3);
  transition: all var(--transition-fast);
}

.floating-arrow svg {
  width: 28px;
  height: 28px;
}

.arrow-left { left: 24px; }
.arrow-right { right: 24px; }

.floating-arrow:hover {
  background: var(--accent-gold);
  color: #111827;
  transform: translateY(-50%) scale(1.08);
  box-shadow: 0 10px 30px var(--accent-gold-glow);
}

.floating-arrow:active {
  transform: translateY(-50%) scale(0.96);
}

.floating-arrow:disabled {
  opacity: 0.3;
  cursor: not-allowed;
  pointer-events: none;
}

/* --- Book Containers --- */
.book-wrapper {
  position: relative;
  width: 100%;
  height: 100%;
  min-height: 0;
  min-width: 0;
  display: flex;
  align-items: center;
  justify-content: center;
  perspective: 2500px;
  overflow: visible;
}

/* StPageFlip Flipbook */
.flipbook {
  position: relative;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.45), 0 4px 16px rgba(0, 0, 0, 0.25);
  border-radius: 6px;
  transition: box-shadow var(--transition-normal);
  margin: 0 auto;
}

#flipbook {
  position: relative;
  display: block;
  margin: 0 auto;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.45), 0 4px 16px rgba(0, 0, 0, 0.25);
  border-radius: 6px;
  transition: box-shadow var(--transition-normal);
  max-width: 100%;
  max-height: 100%;
}

/* StPageFlip Canvas & Wrapper Containment */
#flipbook.stf__parent {
  display: block !important;
  position: relative !important;
  margin: 0 auto !important;
  background: transparent !important;
}

#flipbook .stf__wrapper {
  position: relative !important;
  width: 100% !important;
  height: 100% !important;
  padding-bottom: 0 !important;
  overflow: hidden !important;
  border-radius: 6px !important;
  background: transparent !important;
}

#flipbook canvas,
#flipbook .stf__canvas {
  position: absolute !important;
  width: 100% !important;
  height: 100% !important;
  left: 0 !important;
  top: 0 !important;
  object-fit: contain !important;
  border-radius: 6px !important;
  background: transparent !important;
  image-rendering: -webkit-optimize-contrast;
  transform: translateZ(0);
  backface-visibility: hidden;
  -webkit-font-smoothing: antialiased;
}

/* Page Item Inside StPageFlip */
.book-page-item {
  position: relative;
  width: 100%;
  height: 100%;
  background: transparent;
  overflow: hidden;
  box-shadow: inset 0 0 30px rgba(0, 0, 0, 0.05);
}

.book-page-item canvas {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  display: block;
  object-fit: contain;
  z-index: 2;
  opacity: 0;
  transition: opacity 0.3s ease;
}

.book-page-item.has-rendered canvas {
  opacity: 1;
}

/* Page Skeleton Loader */
.page-skeleton {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: transparent;
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1;
  overflow: hidden;
}

.skeleton-shimmer {
  position: absolute;
  top: 0;
  left: -100%;
  width: 200%;
  height: 100%;
  background: linear-gradient(90deg, 
    transparent 0%, 
    rgba(56, 189, 248, 0.08) 50%, 
    transparent 100%);
  animation: shimmer 1.8s infinite;
}

@keyframes shimmer {
  0% { transform: translateX(0); }
  100% { transform: translateX(100%); }
}

.skeleton-info {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 10px;
  opacity: 0.4;
}

.skeleton-badge {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 800;
  letter-spacing: 3px;
  color: var(--accent-gold);
  border: 1px solid var(--accent-gold);
  padding: 4px 14px;
  border-radius: 20px;
}

.skeleton-num {
  font-size: 13px;
  font-weight: 600;
  color: #64748B;
  letter-spacing: 1px;
}

.book-page-item.has-rendered .page-skeleton {
  opacity: 0;
  pointer-events: none;
}

/* Page Spine Gradient & Paper Edge */
.book-page-item.page-left::after {
  content: '';
  position: absolute;
  top: 0;
  right: 0;
  width: 40px;
  height: 100%;
  background: linear-gradient(to left, rgba(0, 0, 0, 0.18) 0%, rgba(0, 0, 0, 0.04) 60%, transparent 100%);
  pointer-events: none;
  z-index: 5;
}

.book-page-item.page-right::after {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  width: 40px;
  height: 100%;
  background: linear-gradient(to right, rgba(0, 0, 0, 0.18) 0%, rgba(0, 0, 0, 0.04) 60%, transparent 100%);
  pointer-events: none;
  z-index: 5;
}

/* Subtle corner peel indicator */
.corner-hint {
  position: absolute;
  bottom: 0;
  right: 0;
  width: 44px;
  height: 44px;
  background: linear-gradient(135deg, transparent 60%, rgba(56, 189, 248, 0.4) 60%);
  pointer-events: none;
  opacity: 0.7;
  z-index: 10;
  transition: opacity 0.2s ease;
}

.book-page-item:hover .corner-hint {
  opacity: 1;
}

/* Mode 2: Spread View & Zoom Container */
.spread-wrapper {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  overflow: hidden;
  position: relative;
  perspective: 1600px;
}

.spread-viewport {
  width: 100%;
  height: 100%;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: grab;
}

.spread-viewport.grabbing {
  cursor: grabbing;
}

.spread-canvas-card {
  position: relative;
  box-shadow: 0 16px 48px rgba(0, 0, 0, 0.45), 0 4px 16px rgba(0, 0, 0, 0.25);
  border-radius: 6px;
  overflow: hidden;
  background: #FFFFFF;
  transition: transform 0.1s ease-out;
  transform-origin: center center;
  max-width: calc(100% - 140px);
  max-height: calc(100% - 20px);
  display: flex;
  align-items: center;
  justify-content: center;
}

.spread-canvas-card.flipping-next {
  animation: spreadFlipNext 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

.spread-canvas-card.flipping-prev {
  animation: spreadFlipPrev 0.45s cubic-bezier(0.4, 0, 0.2, 1);
}

@keyframes spreadFlipNext {
  0% { transform: perspective(1400px) rotateY(0deg) scale(1); opacity: 1; }
  45% { transform: perspective(1400px) rotateY(-14deg) scale(0.97); opacity: 0.85; }
  100% { transform: perspective(1400px) rotateY(0deg) scale(1); opacity: 1; }
}

@keyframes spreadFlipPrev {
  0% { transform: perspective(1400px) rotateY(0deg) scale(1); opacity: 1; }
  45% { transform: perspective(1400px) rotateY(14deg) scale(0.97); opacity: 0.85; }
  100% { transform: perspective(1400px) rotateY(0deg) scale(1); opacity: 1; }
}

.spread-canvas-card canvas,
.spread-canvas-card img.spread-img {
  display: block;
  max-width: 100%;
  max-height: calc(100dvh - var(--nav-height) - var(--dock-height) - 36px);
  width: auto;
  height: auto;
  object-fit: contain;
  user-select: none;
  -webkit-user-drag: none;
  border-radius: 6px;
}

.spread-spine-overlay {
  position: absolute;
  top: 0;
  left: 50%;
  transform: translateX(-50%);
  width: 48px;
  height: 100%;
  background: linear-gradient(to right, 
    rgba(0, 0, 0, 0.03) 0%, 
    rgba(0, 0, 0, 0.22) 50%, 
    rgba(0, 0, 0, 0.03) 100%);
  pointer-events: none;
  box-shadow: 0 0 10px rgba(0,0,0,0.1);
}

/* --- Loading Overlay --- */
.loading-overlay {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  background: var(--bg-glass-strong);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  z-index: 100;
  transition: opacity 0.25s ease, visibility 0.25s ease;
  will-change: opacity;
}

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

.spinner-crest {
  position: relative;
  width: 80px;
  height: 80px;
  display: flex;
  align-items: center;
  justify-content: center;
  margin-bottom: 24px;
}

.crest-ring {
  position: absolute;
  width: 100%;
  height: 100%;
  border-radius: 50%;
  border: 3px solid rgba(56, 189, 248, 0.2);
  border-top-color: var(--accent-gold);
  border-right-color: var(--accent-cyan);
  animation: spin 1.2s cubic-bezier(0.68, -0.55, 0.27, 1.55) infinite;
}

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

.crest-icon {
  font-family: var(--font-serif);
  font-size: 36px;
  font-weight: 800;
  color: var(--accent-gold);
}

.loading-title {
  font-family: var(--font-serif);
  font-size: 22px;
  letter-spacing: 2px;
  color: var(--text-primary);
  margin-bottom: 8px;
}

.loading-sub {
  font-size: 14px;
  color: var(--text-secondary);
  margin-bottom: 20px;
}

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

.loading-bar-progress {
  height: 100%;
  width: 15%;
  background: linear-gradient(90deg, var(--accent-gold), var(--accent-cyan));
  border-radius: 3px;
  transition: width 0.3s ease;
}

/* --- Bottom Dock --- */
.bottom-dock {
  flex: 0 0 auto;
  position: relative;
  width: calc(100% - 32px);
  max-width: 1920px;
  height: var(--dock-height);
  margin: 0 auto max(12px, var(--safe-bottom)) auto;
  background: var(--bg-glass);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--border-glass);
  border-radius: 18px;
  box-shadow: 0 10px 32px rgba(0, 0, 0, 0.45);
  z-index: 50;
  display: flex;
  align-items: center;
  padding: 0 16px;
}

.dock-container {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  gap: 16px;
}

.dock-group {
  display: flex;
  align-items: center;
  gap: 8px;
}

.dock-btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 38px;
  height: 38px;
  border-radius: 10px;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-fast);
}

.dock-btn:hover {
  color: var(--text-primary);
  background: rgba(255, 255, 255, 0.12);
  border-color: var(--accent-gold);
  transform: translateY(-2px);
}

.dock-btn.active {
  color: var(--accent-gold);
  border-color: var(--accent-gold);
  background: rgba(56, 189, 248, 0.18);
}

.dock-btn .icon {
  width: 20px;
  height: 20px;
}

.dock-separator {
  width: 1px;
  height: 24px;
  background: var(--border-subtle);
  margin: 0 4px;
}

/* Scrubber Slider */
.dock-center {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 6px;
  max-width: 520px;
}

.scrubber-track-wrap {
  position: relative;
  width: 100%;
}

.scrubber-slider {
  -webkit-appearance: none;
  width: 100%;
  height: 6px;
  border-radius: 3px;
  background: rgba(255, 255, 255, 0.12);
  outline: none;
  cursor: pointer;
  transition: background var(--transition-fast);
}

.scrubber-slider:hover {
  background: rgba(255, 255, 255, 0.2);
}

.scrubber-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-gold);
  box-shadow: 0 0 10px var(--accent-gold);
  cursor: pointer;
  transition: transform var(--transition-fast);
}

.scrubber-slider::-webkit-slider-thumb:hover {
  transform: scale(1.3);
}

.scrubber-tooltip {
  position: absolute;
  bottom: calc(100% + 10px);
  left: 50%;
  transform: translateX(-50%);
  background: var(--bg-glass-strong);
  border: 1px solid var(--border-glass);
  color: var(--accent-gold);
  padding: 4px 10px;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 600;
  white-space: nowrap;
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--transition-fast);
  box-shadow: 0 4px 14px rgba(0, 0, 0, 0.4);
}

.scrubber-track-wrap:hover .scrubber-tooltip {
  opacity: 1;
}

.page-status-pill {
  display: flex;
  align-items: center;
  gap: 8px;
  font-size: 12px;
  color: var(--text-secondary);
}

.page-indicator {
  font-weight: 700;
  color: var(--text-primary);
}

.status-bullet {
  color: var(--text-muted);
}

.current-chapter-pill {
  max-width: 220px;
  overflow: hidden;
  text-overflow: ellipsis;
  white-space: nowrap;
  color: var(--accent-gold);
  font-weight: 500;
}

/* Direct Jump Box */
.jump-box {
  display: flex;
  align-items: center;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-subtle);
  border-radius: 8px;
  padding: 2px 4px;
}

.jump-field {
  width: 52px;
  background: none;
  border: none;
  color: var(--text-primary);
  font-size: 13px;
  font-weight: 600;
  text-align: center;
  outline: none;
}

.jump-field::-webkit-inner-spin-button,
.jump-field::-webkit-outer-spin-button {
  -webkit-appearance: none;
  margin: 0;
}

.jump-go-btn {
  padding: 4px 8px;
  background: var(--accent-gold);
  color: #111827;
  border-radius: 6px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.5px;
  transition: all var(--transition-fast);
}

.jump-go-btn:hover {
  filter: brightness(1.1);
  transform: scale(1.05);
}

/* Zoom Controls */
.zoom-controls {
  display: flex;
  align-items: center;
  gap: 4px;
  background: rgba(255, 255, 255, 0.03);
  padding: 2px;
  border-radius: 10px;
  border: 1px solid var(--border-subtle);
}

.zoom-level {
  font-size: 12px;
  font-weight: 600;
  min-width: 44px;
  text-align: center;
  color: var(--text-secondary);
}

/* Reading Stage Zoom & Pan Cursor States */
.reading-stage.is-zoomed {
  cursor: grab;
}

.reading-stage.is-zoomed.is-panning {
  cursor: grabbing;
}

.reading-stage.is-zoomed #flipbook,
.reading-stage.is-zoomed .spread-canvas-card {
  cursor: grab;
}

.reading-stage.is-zoomed.is-panning #flipbook,
.reading-stage.is-zoomed.is-panning .spread-canvas-card {
  cursor: grabbing;
}

/* --- Side Drawers --- */
.side-drawer {
  position: fixed;
  top: 0;
  left: 0;
  width: 420px;
  max-width: 90vw;
  height: 100vh;
  background: var(--bg-glass-strong);
  backdrop-filter: blur(28px);
  -webkit-backdrop-filter: blur(28px);
  border-right: 1px solid var(--border-glass);
  box-shadow: 15px 0 45px rgba(0, 0, 0, 0.5);
  z-index: 110;
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform 0.35s cubic-bezier(0.16, 1, 0.3, 1);
}

.side-drawer.wide-drawer {
  width: 600px;
}

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

.drawer-header {
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 20px;
  border-bottom: 1px solid var(--border-glass);
}

.drawer-title-wrap {
  display: flex;
  align-items: center;
  gap: 12px;
}

.drawer-icon {
  width: 22px;
  height: 22px;
  color: var(--accent-gold);
}

.drawer-title {
  font-family: var(--font-serif);
  font-size: 17px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text-primary);
}

.drawer-close-btn {
  width: 32px;
  height: 32px;
  border-radius: 8px;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.drawer-close-btn:hover {
  background: rgba(255, 255, 255, 0.1);
  color: var(--text-primary);
}

.drawer-content {
  flex: 1;
  overflow-y: auto;
  padding: 16px;
}

/* Custom Scrollbar */
.drawer-content::-webkit-scrollbar {
  width: 6px;
}
.drawer-content::-webkit-scrollbar-thumb {
  background: rgba(255, 255, 255, 0.15);
  border-radius: 3px;
}
.drawer-content::-webkit-scrollbar-thumb:hover {
  background: var(--accent-gold);
}

/* TOC Filter Bar */
.toc-filter-bar {
  display: flex;
  gap: 6px;
  padding: 12px 16px;
  border-bottom: 1px solid var(--border-subtle);
  overflow-x: auto;
  white-space: nowrap;
}

.toc-tab {
  padding: 6px 12px;
  border-radius: 20px;
  font-size: 12px;
  font-weight: 500;
  color: var(--text-secondary);
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  transition: all var(--transition-fast);
}

.toc-tab:hover {
  color: var(--text-primary);
  border-color: var(--accent-gold);
}

.toc-tab.active {
  background: var(--accent-gold);
  color: #111827;
  font-weight: 700;
  border-color: var(--accent-gold);
}

/* TOC Item Cards */
.toc-part-header {
  font-size: 11px;
  text-transform: uppercase;
  letter-spacing: 1.5px;
  font-weight: 700;
  color: var(--accent-gold);
  margin: 16px 0 8px 6px;
}

.toc-entry {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 12px;
  border-radius: 10px;
  margin-bottom: 4px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid transparent;
  transition: all var(--transition-fast);
  cursor: pointer;
}

.toc-entry:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: var(--border-glass);
  transform: translateX(4px);
}

.toc-entry.active {
  background: rgba(56, 189, 248, 0.12);
  border-color: var(--accent-gold);
}

.toc-entry-title {
  font-size: 13px;
  font-weight: 500;
  color: var(--text-primary);
  max-width: 290px;
  line-height: 1.4;
}

.toc-entry-badge {
  font-size: 11px;
  font-weight: 600;
  padding: 3px 8px;
  border-radius: 12px;
  background: rgba(255, 255, 255, 0.06);
  color: var(--text-secondary);
}

.toc-entry.active .toc-entry-badge {
  background: var(--accent-gold);
  color: #111827;
}

/* Search Drawer Styles */
.search-input-wrap {
  position: relative;
  padding: 16px;
  border-bottom: 1px solid var(--border-subtle);
}

.search-field {
  width: 100%;
  padding: 12px 40px 12px 14px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.05);
  border: 1px solid var(--border-glass);
  color: var(--text-primary);
  font-size: 14px;
  outline: none;
  transition: all var(--transition-fast);
}

.search-field:focus {
  border-color: var(--accent-gold);
  box-shadow: 0 0 12px var(--accent-gold-glow);
}

.clear-btn {
  position: absolute;
  right: 26px;
  top: 50%;
  transform: translateY(-50%);
  color: var(--text-muted);
  font-size: 14px;
}

.search-chips {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 6px;
  padding: 10px 16px;
  border-bottom: 1px solid var(--border-subtle);
}

.chips-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-muted);
}

.chip {
  padding: 4px 10px;
  border-radius: 14px;
  font-size: 11px;
  background: rgba(255, 255, 255, 0.04);
  border: 1px solid var(--border-subtle);
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.chip:hover {
  background: var(--accent-gold);
  color: #111827;
  border-color: var(--accent-gold);
}

.search-results-meta {
  padding: 10px 16px;
  font-size: 12px;
  color: var(--text-muted);
  border-bottom: 1px solid var(--border-subtle);
}

.search-result-card {
  padding: 12px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid transparent;
  margin-bottom: 8px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.search-result-card:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: var(--border-glass);
  transform: translateX(4px);
}

.search-result-header {
  display: flex;
  justify-content: space-between;
  margin-bottom: 6px;
  font-size: 12px;
  font-weight: 600;
  color: var(--accent-gold);
}

.search-result-snippet {
  font-size: 13px;
  line-height: 1.5;
  color: var(--text-secondary);
}

.search-result-snippet mark {
  background: rgba(56, 189, 248, 0.35);
  color: #FFFFFF;
  padding: 1px 3px;
  border-radius: 3px;
}

/* Thumbnails Grid */
.thumbs-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(130px, 1fr));
  gap: 14px;
  padding: 16px;
}

.thumb-card {
  border-radius: 8px;
  overflow: hidden;
  background: rgba(255, 255, 255, 0.03);
  border: 1px solid var(--border-subtle);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  flex-direction: column;
}

.thumb-card:hover {
  transform: translateY(-4px);
  border-color: var(--accent-gold);
  box-shadow: 0 8px 20px rgba(0, 0, 0, 0.4);
}

.thumb-card.active {
  border-color: var(--accent-gold);
  box-shadow: 0 0 16px var(--accent-gold-glow);
}

.thumb-preview {
  width: 100%;
  aspect-ratio: 4 / 3;
  background: #1E293B;
  position: relative;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 11px;
  color: var(--text-muted);
  overflow: hidden;
}

.thumb-preview img,
.thumb-preview canvas {
  width: 100%;
  height: 100%;
  object-fit: cover;
  display: block;
}

.thumb-info {
  padding: 8px;
  font-size: 11px;
  font-weight: 600;
  color: var(--text-secondary);
  display: flex;
  justify-content: space-between;
  background: rgba(0, 0, 0, 0.2);
}

.thumb-card.active .thumb-info {
  color: var(--accent-gold);
}

/* Bookmarks List */
.bookmark-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px;
  border-radius: 10px;
  background: rgba(255, 255, 255, 0.02);
  border: 1px solid var(--border-subtle);
  margin-bottom: 8px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.bookmark-card:hover {
  background: rgba(255, 255, 255, 0.06);
  border-color: var(--accent-gold);
}

.bookmark-info {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.bookmark-page {
  font-weight: 700;
  color: var(--accent-gold);
  font-size: 13px;
}

.bookmark-chapter {
  font-size: 12px;
  color: var(--text-secondary);
}

.bookmark-remove {
  padding: 6px;
  color: var(--text-muted);
  border-radius: 6px;
  transition: all var(--transition-fast);
}

.bookmark-remove:hover {
  color: #EF4444;
  background: rgba(239, 68, 68, 0.15);
}

.empty-state {
  text-align: center;
  padding: 40px 20px;
  font-size: 13px;
  color: var(--text-muted);
  line-height: 1.6;
}

/* Modal Help Dialog */
.modal-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.65);
  backdrop-filter: blur(8px);
  -webkit-backdrop-filter: blur(8px);
  display: none;
  align-items: center;
  justify-content: center;
  z-index: 120;
}

.modal-backdrop.show {
  display: flex;
  animation: fadeIn 0.2s ease;
}

.modal-card {
  width: 500px;
  max-width: 90vw;
  background: var(--bg-glass-strong);
  backdrop-filter: blur(24px);
  -webkit-backdrop-filter: blur(24px);
  border: 1px solid var(--border-glass);
  border-radius: 18px;
  box-shadow: 0 20px 50px rgba(0, 0, 0, 0.6);
  overflow: hidden;
}

.modal-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 16px 20px;
  border-bottom: 1px solid var(--border-glass);
}

.modal-title {
  font-family: var(--font-serif);
  font-size: 16px;
  font-weight: 700;
  color: var(--accent-gold);
}

.modal-close-btn {
  font-size: 16px;
  color: var(--text-muted);
  padding: 4px;
}

.modal-close-btn:hover {
  color: var(--text-primary);
}

.modal-body {
  padding: 20px;
  max-height: 70vh;
  overflow-y: auto;
}

.shortcut-grid {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.shortcut-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 10px;
  border-radius: 8px;
  background: rgba(255, 255, 255, 0.03);
}

.shortcut-row .keys {
  display: flex;
  gap: 4px;
}

kbd {
  display: inline-block;
  padding: 3px 8px;
  font-size: 12px;
  font-family: inherit;
  font-weight: 700;
  color: var(--accent-gold);
  background: rgba(56, 189, 248, 0.15);
  border: 1px solid var(--accent-gold);
  border-radius: 6px;
}

.shortcut-row .desc {
  font-size: 13px;
  color: var(--text-secondary);
}

/* Drawer Backdrop */
.drawer-backdrop {
  position: fixed;
  top: 0;
  left: 0;
  width: 100vw;
  height: 100vh;
  background: rgba(0, 0, 0, 0.5);
  backdrop-filter: blur(4px);
  -webkit-backdrop-filter: blur(4px);
  z-index: 105;
  display: none;
}

.drawer-backdrop.show {
  display: block;
}

/* --- Comprehensive Responsive Media Queries --- */

/* Tablets, iPads (Portrait & Landscape), and Touch Devices */
@media (max-width: 1024px),
       (orientation: landscape) and (max-height: 1024px) and (max-width: 1400px),
       (orientation: landscape) and (any-pointer: coarse),
       (any-pointer: coarse),
       (pointer: coarse) and (max-width: 1400px),
       (hover: none) and (max-width: 1400px) {
  .book-subtitle { display: none; }
  .btn-label { display: none; }

  /* Hide bottom dock footer on all iPad, tablet, landscape, and touch devices */
  .bottom-dock {
    display: none !important;
  }

  /* Provide comfortable bottom breathing room down to the safe area */
  .reading-stage {
    padding-bottom: max(16px, var(--safe-bottom));
  }
}

/* JavaScript Device & Orientation State Classes */
body.is-landscape-tablet .bottom-dock,
body.touch-device .bottom-dock,
body.tablet-device .bottom-dock,
body.portrait-mode .bottom-dock,
html.touch-device .bottom-dock {
  display: none !important;
}

body.is-landscape-tablet .reading-stage,
body.touch-device .reading-stage,
body.tablet-device .reading-stage,
body.portrait-mode .reading-stage,
html.touch-device .reading-stage {
  padding-bottom: max(16px, var(--safe-bottom));
}

/* Tablets in Portrait, Foldables & Large Phones (<= 768px) */
@media (max-width: 768px) {
  :root {
    --nav-height: 54px;
    --dock-height: 58px;
  }

  .top-nav {
    height: var(--nav-height);
    padding: var(--safe-top) max(14px, var(--safe-right)) 0 max(14px, var(--safe-left));
  }

  .nav-back-btn {
    padding: 6px 12px;
    font-size: 12.5px;
  }

  .nav-actions {
    gap: 8px;
  }

  .action-btn {
    height: 35px;
    padding: 0 13px;
    font-size: 12.5px;
    gap: 6px;
  }

  .action-btn .icon {
    width: 15px;
    height: 15px;
  }

  .nav-zoom-control {
    height: 35px;
    padding: 2px 4px;
    gap: 1px;
  }

  .zoom-btn {
    height: 28px;
  }

  .zoom-btn-out,
  .zoom-btn-in {
    width: 28px;
  }

  .zoom-btn-out .icon,
  .zoom-btn-in .icon {
    width: 15px;
    height: 15px;
  }

  .zoom-btn-level {
    padding: 0 6px;
    font-size: 11.5px;
    min-width: 44px;
  }

  #btnHelp,
  #btnBookmark,
  #btnAudio,
  #btnFullscreen,
  .nav-divider {
    display: none !important;
  }

  /* Stage & Floating Arrows */
  .reading-stage {
    padding: 6px 12px;
  }

  /* Hide floating arrows on phone & tablet portrait; thumb swipe handles navigation cleanly */
  .floating-arrow {
    display: none !important;
  }

  /* Bottom Dock - hidden on mobile and tablets */
  .bottom-dock {
    display: none !important;
  }

  /* Drawers: full viewport width on mobile */
  .side-drawer,
  .side-drawer.wide-drawer {
    width: 100vw;
    max-width: 100vw;
    border-radius: 0;
  }

  .thumbs-grid {
    grid-template-columns: repeat(3, 1fr);
    gap: 10px;
    padding: 12px;
  }
}

/* Standard Mobile Devices (<= 540px) */
@media (max-width: 540px) {
  :root {
    --nav-height: 48px;
    --dock-height: 52px;
  }

  .top-nav {
    height: var(--nav-height);
    padding: var(--safe-top) max(10px, var(--safe-right)) 0 max(10px, var(--safe-left));
  }

  .nav-back-btn {
    padding: 5px 10px;
    font-size: 12px;
  }

  .nav-actions {
    gap: 6px;
  }

  .action-btn {
    height: 33px;
    padding: 0 11px;
    font-size: 12px;
    gap: 5px;
  }

  .action-btn .icon {
    width: 14px;
    height: 14px;
  }

  .nav-zoom-control {
    height: 32px;
    padding: 2px 3px;
    gap: 1px;
  }

  .zoom-btn {
    height: 26px;
  }

  .zoom-btn-out,
  .zoom-btn-in {
    width: 26px;
  }

  .zoom-btn-out .icon,
  .zoom-btn-in .icon {
    width: 14px;
    height: 14px;
  }

  .zoom-btn-level {
    padding: 0 5px;
    font-size: 11px;
    min-width: 40px;
  }

  .reading-stage {
    padding: 4px 8px;
  }

  /* Bottom Dock Mobile Layout */
  .bottom-dock {
    display: none !important;
  }

  .dock-btn.icon-only {
    width: 36px;
    height: 36px;
    padding: 6px;
  }

  .dock-btn .icon {
    width: 19px;
    height: 19px;
  }

  .page-indicator {
    font-size: 10.5px;
    font-weight: 600;
  }

  .spread-indicator {
    font-size: 10px;
  }

  /* Drawer Improvements on Phone */
  .drawer-header {
    height: 50px;
    padding: 0 14px;
  }

  .drawer-title {
    font-size: 15px;
  }

  .drawer-close-btn {
    width: 38px;
    height: 38px;
    font-size: 18px;
  }

  .drawer-content {
    padding: 10px;
    padding-bottom: max(32px, var(--safe-bottom));
  }

  .toc-entry {
    padding: 11px 10px;
    min-height: 44px;
  }

  .toc-entry-title {
    font-size: 12.5px;
    max-width: 210px;
  }

  .thumbs-grid {
    grid-template-columns: repeat(2, 1fr);
    gap: 8px;
    padding: 8px;
  }

  /* Crucial for iOS: 16px font-size prevents viewport auto-zooming on focus */
  .search-field {
    font-size: 16px;
    padding: 10px 36px 10px 12px;
  }

  /* Spread Card Mobile Containment */
  .spread-canvas-card canvas,
  .spread-canvas-card img.spread-img {
    max-width: 100%;
    max-height: 100%;
  }
}

/* Compact Mobile Actions (<= 440px) */
@media (max-width: 440px) {
  .action-btn-toc .action-btn-label,
  .action-btn-amazon .action-btn-label,
  .action-btn-download .action-btn-label {
    display: none;
  }
  .action-btn {
    padding: 0 9px;
  }
  .nav-back-btn .back-text {
    display: none;
  }
}

/* Extra Small Phones (<= 380px, e.g. iPhone SE / Galaxy Mini) */
@media (max-width: 380px) {
  .book-main-title {
    display: none;
  }

  .nav-brand {
    gap: 0;
  }

  .page-indicator {
    font-size: 9.5px;
  }

  .spread-indicator {
    font-size: 9px;
  }
}

/* Mobile Landscape Orientation (Optimized for side-by-side reading on phones) */
@media (max-height: 520px) and (orientation: landscape) {
  :root {
    --nav-height: 40px;
    --dock-height: 44px;
  }

  .top-nav {
    height: var(--nav-height);
    padding: var(--safe-top) max(12px, var(--safe-right)) 0 max(12px, var(--safe-left));
  }

  .top-nav {
    height: 40px;
    padding: var(--safe-top) max(10px, var(--safe-right)) 0 max(10px, var(--safe-left));
  }

  .nav-back-btn {
    padding: 4px 8px;
    font-size: 11px;
  }

  .action-btn {
    height: 30px;
    padding: 0 10px;
    font-size: 11.5px;
    gap: 4px;
  }

  .action-btn .icon {
    width: 13px;
    height: 13px;
  }

  #btnHelp,
  #btnBookmark,
  #btnAudio,
  #btnFullscreen,
  .nav-divider {
    display: none !important;
  }

  /* Stage & Spread Container in Landscape */
  .reading-stage {
    padding: 2px 8px;
  }

  .floating-arrow {
    width: 32px;
    height: 32px;
  }

  .floating-arrow svg {
    width: 16px;
    height: 16px;
  }

  .arrow-left { left: 4px; }
  .arrow-right { right: 4px; }

  /* Bottom Dock Landscape Layout */
  .bottom-dock {
    display: none !important;
  }

  .dock-btn.icon-only {
    width: 30px;
    height: 30px;
    padding: 4px;
  }

  .dock-btn .icon {
    width: 16px;
    height: 16px;
  }

  .dock-left #btnFirst,
  .dock-right #btnLast,
  .dock-right #btnAutoplay,
  .dock-separator,
  .dock-right .jump-box {
    display: none;
  }

  .page-status-pill {
    font-size: 10px;
    padding: 1px 6px;
  }

  .page-status-pill .current-chapter-pill,
  .page-status-pill .status-bullet {
    display: none;
  }

  .spread-canvas-card canvas,
  .spread-canvas-card img.spread-img {
    max-height: 100%;
    max-width: 100%;
  }
}