/* ==========================================================================
   AURA — Pure Native Mobile Reading Instrument
   Engineered for Visual Ergonomics, Editorial Elegance & Asthenopia Prevention
   ========================================================================== */

:root {
  /* Editorial Typographic Families */
  --font-literata: 'Literata', Georgia, serif;
  --font-garamond: 'Cormorant Garamond', Georgia, serif;
  --font-newsreader: 'Newsreader', Georgia, serif;
  --font-lora: 'Lora', Georgia, serif;
  --font-serif: var(--font-literata);
  --font-sans: 'Inter', -apple-system, BlinkMacSystemFont, 'SF Pro Text', sans-serif;
  --font-display: 'Cormorant Garamond', 'Playfair Display', Georgia, serif;
  --font-mono: 'JetBrains Mono', Menlo, Consolas, monospace;

  /* Dynamic Reading Settings (Mobile Baseline) */
  --read-font-size: 18.5px;
  --read-line-height: 1.78;
  --read-font-family: var(--font-serif);

  /* Physics & Spring Easings */
  --ease-spring: cubic-bezier(0.32, 0.72, 0, 1);
  --ease-smooth: cubic-bezier(0.16, 1, 0.3, 1);
  --duration-fast: 180ms;
  --duration-norm: 280ms;

  /* Elevation Shadows */
  --shadow-subtle: 0 1px 3px rgba(0, 0, 0, 0.05), 0 1px 2px rgba(0, 0, 0, 0.03);
  --shadow-card: 0 4px 16px rgba(0, 0, 0, 0.06), 0 1px 4px rgba(0, 0, 0, 0.04);
  --shadow-dock: 0 -4px 20px rgba(0, 0, 0, 0.07), 0 -1px 3px rgba(0, 0, 0, 0.03);
  --shadow-sheet: 0 -10px 40px rgba(0, 0, 0, 0.18);

  /* Radii Tokens */
  --radius-xs: 4px;
  --radius-sm: 8px;
  --radius-md: 14px;
  --radius-lg: 20px;
  --radius-xl: 28px;
  --radius-full: 9999px;
}

/* ==========================================================================
   5 SCIENTIFIC VISUAL COMFORT PALETTES
   ========================================================================== */

/* 1. NATURAL PARCHMENT (Daylight Warmth — 12.2:1 Soft Contrast, Zero Glare) */
[data-theme="parchment"] {
  --bg-canvas: #F8F5EE;
  --bg-surface: #FFFFFF;
  --bg-elevated: #F1ECE2;
  --bg-subtle: #E8E2D4;

  --text-primary: #23211E;
  --text-secondary: #6B655B;
  --text-tertiary: #968F83;

  --border-hairline: #E4DDCF;
  --border-strong: #CDC4B3;

  --accent-crimson: #991B1B;     /* Deep Oxford Crimson */
  --accent-light: #FEE2E2;
  --accent-hover: #7F1D1D;

  --read-bg: #FAF7F0;
  --read-text: #23211E;
  --read-quote-bg: #F2EDE2;

  --dock-bg: rgba(255, 255, 255, 0.88);
}

/* 2. CANDLELIGHT SEPIA (Evening Melatonin Safe — Blue Filtered < 450nm) */
[data-theme="sepia"] {
  --bg-canvas: #EFE6D2;
  --bg-surface: #E5DAC2;
  --bg-elevated: #DBCFBA;
  --bg-subtle: #D0C3AC;

  --text-primary: #34281B;
  --text-secondary: #6A563D;
  --text-tertiary: #8F7657;

  --border-hairline: #D3C5AB;
  --border-strong: #BFB093;

  --accent-crimson: #9A3412;     /* Warm Terracotta Carmine */
  --accent-light: #FFEDD5;
  --accent-hover: #7C2D12;

  --read-bg: #EFE6D2;
  --read-text: #34281B;
  --read-quote-bg: #E4D8BE;

  --dock-bg: rgba(229, 218, 194, 0.88);
}

/* 3. OBSIDIAN NIGHT (OLED Anti-Astigmatism Halation) */
[data-theme="obsidian"] {
  --bg-canvas: #0A0B0E;
  --bg-surface: #14161D;
  --bg-elevated: #1D202A;
  --bg-subtle: #272B38;

  --text-primary: #CBD0D8;       /* Pearl Silver, Never Stark #FFF */
  --text-secondary: #9097A6;
  --text-tertiary: #5E6575;

  --border-hairline: #202430;
  --border-strong: #2F3547;

  --accent-crimson: #E11D48;     /* Luminous Soft Ruby */
  --accent-light: #2A1017;
  --accent-hover: #F43F5E;

  --read-bg: #0A0B0E;
  --read-text: #CBD0D8;
  --read-quote-bg: #14161F;

  --dock-bg: rgba(20, 22, 29, 0.88);
}

/* 4. IMPERIAL VELVET (Burgundy Luxury Wine) */
[data-theme="burgundy"] {
  --bg-canvas: #120A0F;
  --bg-surface: #1E121A;
  --bg-elevated: #2B1A25;
  --bg-subtle: #3A2332;

  --text-primary: #F0E5EC;
  --text-secondary: #B49BAA;
  --text-tertiary: #7D6474;

  --border-hairline: #331E2C;
  --border-strong: #4B2E42;

  --accent-crimson: #F43F5E;     /* Velvet Ruby */
  --accent-light: #34111E;
  --accent-hover: #FB7185;

  --read-bg: #120A0F;
  --read-text: #EFE4EA;
  --read-quote-bg: #20131B;

  --dock-bg: rgba(30, 18, 26, 0.9);
}

/* 5. PURE E-PAPER (Tactile Monochrome Ink) */
[data-theme="epaper"] {
  --bg-canvas: #E6E6E6;
  --bg-surface: #F0F0F0;
  --bg-elevated: #DADADA;
  --bg-subtle: #CCCCCC;

  --text-primary: #121212;
  --text-secondary: #4A4A4A;
  --text-tertiary: #7A7A7A;

  --border-hairline: #B8B8B8;
  --border-strong: #909090;

  --accent-crimson: #181818;
  --accent-light: #D6D6D6;
  --accent-hover: #000000;

  --read-bg: #EAEAEA;
  --read-text: #121212;
  --read-quote-bg: #DADADA;

  --dock-bg: rgba(240, 240, 240, 0.92);
}

/* ==========================================================================
   RESET & PURE MOBILE VIEWPORT CONTAINER
   ========================================================================== */

*, *::before, *::after {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

html, body {
  width: 100%;
  height: 100%;
  overflow: hidden;
  background-color: var(--bg-canvas);
  color: var(--text-primary);
  font-family: var(--font-sans);
  touch-action: pan-y;
  -webkit-tap-highlight-color: transparent;
  user-select: none;
}

/* The Mobile Application Shell (Centers gracefully on large screens, fills 100% on phones) */
.mobile-app-shell {
  width: 100vw;
  height: 100dvh;
  max-width: 480px; /* Elegant mobile constraint if viewed on tablet/desktop */
  margin: 0 auto;
  position: relative;
  background-color: var(--bg-canvas);
  overflow: hidden;
  display: flex;
  flex-direction: column;
  transition: background-color var(--duration-norm) ease, color var(--duration-norm) ease;
}

@media (min-width: 481px) {
  body {
    background-color: #0E1015;
    display: flex;
    align-items: center;
    justify-content: center;
  }
  .mobile-app-shell {
    height: 92dvh;
    max-height: 860px;
    border-radius: 40px;
    box-shadow: 0 25px 70px -15px rgba(0, 0, 0, 0.7), 0 0 0 1px rgba(255, 255, 255, 0.08);
  }
}

/* Screen Transitions */
.app-screen {
  display: none;
  width: 100%;
  height: 100%;
  flex-direction: column;
  position: relative;
  animation: screenFadeIn var(--duration-fast) var(--ease-smooth);
}

.app-screen.active {
  display: flex;
}

@keyframes screenFadeIn {
  from { opacity: 0; transform: scale(0.99); }
  to { opacity: 1; transform: scale(1); }
}

/* ==========================================================================
   SCREEN 1: LIBRARY & CATALOGUE STYLING
   ========================================================================== */

.mobile-header {
  padding-top: max(16px, env(safe-area-inset-top, 16px));
  padding-left: 20px;
  padding-right: 20px;
  padding-bottom: 12px;
  background: var(--bg-surface);
  border-bottom: 1px solid var(--border-hairline);
  flex-shrink: 0;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.header-top-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.brand-signature {
  display: flex;
  align-items: center;
  gap: 10px;
}

.brand-monogram {
  width: 34px;
  height: 34px;
  background: linear-gradient(135deg, var(--accent-crimson), #7F1D1D);
  border-radius: var(--radius-sm);
  color: #FFFFFF;
  font-family: var(--font-display);
  font-size: 20px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 3px 8px rgba(153, 27, 27, 0.3);
}

.brand-monogram-img {
  width: 34px;
  height: 34px;
  border-radius: 9px;
  box-shadow: 0 3px 10px rgba(0, 0, 0, 0.25);
  object-fit: cover;
  flex-shrink: 0;
}

.brand-titles {
  display: flex;
  flex-direction: column;
}

.brand-name {
  font-family: var(--font-display);
  font-size: 19px;
  font-weight: 700;
  letter-spacing: 1.5px;
  color: var(--text-primary);
  line-height: 1.1;
}

.brand-tagline {
  font-size: 10.5px;
  font-weight: 700;
  letter-spacing: 1.4px;
  color: var(--text-tertiary);
  text-transform: uppercase;
  margin-top: 2px;
}

.header-actions {
  display: flex;
  align-items: center;
  gap: 10px;
}

.eye-health-pill {
  display: flex;
  align-items: center;
  gap: 6px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  padding: 5px 10px;
  border-radius: var(--radius-full);
  font-size: 11.5px;
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
}

.pulse-indicator {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: #10B981;
  box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.6);
  animation: pulse-ring 2s infinite;
}

@keyframes pulse-ring {
  0% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0.6); }
  70% { transform: scale(1.1); box-shadow: 0 0 0 6px rgba(16, 185, 129, 0); }
  100% { transform: scale(0.95); box-shadow: 0 0 0 0 rgba(16, 185, 129, 0); }
}

.nav-icon-button {
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  color: var(--text-secondary);
  width: 34px;
  height: 34px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  transition: all var(--duration-fast);
}

.nav-icon-button:active {
  transform: scale(0.94);
  background: var(--bg-subtle);
}

/* Search Field */
.search-field-container {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: 9px 14px;
  transition: border-color var(--duration-fast);
}

.search-field-container:focus-within {
  border-color: var(--accent-crimson);
  background: var(--bg-surface);
}

.search-icon {
  color: var(--text-tertiary);
  flex-shrink: 0;
}

.search-input {
  background: transparent;
  border: none;
  outline: none;
  font-family: inherit;
  font-size: 15px;
  color: var(--text-primary);
  width: 100%;
}

.search-input::placeholder {
  color: var(--text-tertiary);
}

/* ======================================================== */
/* ZERO-SCROLL FORMAT MATRIX & SEGMENTED CONTROLLER        */
/* ======================================================== */
.format-matrix-wrapper {
  display: flex;
  flex-direction: column;
  gap: 8px;
  width: 100%;
}

.format-segmented-track {
  display: flex;
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  padding: 3px;
  gap: 3px;
  width: 100%;
}

.format-segment-btn {
  flex: 1;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 5px;
  padding: 8px 4px;
  border: none;
  background: transparent;
  color: var(--text-secondary);
  border-radius: calc(var(--radius-sm) - 2px);
  cursor: pointer;
  transition: all var(--duration-fast);
  user-select: none;
}

.format-segment-btn:active {
  transform: scale(0.97);
}

.format-segment-btn.active {
  background: var(--bg-surface);
  color: var(--text-primary);
  font-weight: 700;
  box-shadow: 0 2px 6px rgba(0, 0, 0, 0.08), 0 0 0 1px var(--border-hairline);
}

.format-segment-btn .segment-label {
  font-size: 12.5px;
  font-weight: 700;
  letter-spacing: 0.3px;
}

.format-segment-btn .segment-count {
  font-size: 11px;
  padding: 1px 6px;
  border-radius: var(--radius-full);
  background: var(--bg-subtle);
  color: var(--text-tertiary);
  font-weight: 700;
  transition: all var(--duration-fast);
}

.format-segment-btn.active .segment-count {
  background: var(--accent-light);
  color: var(--accent-crimson);
}

/* Format Color Dots */
.format-dot {
  width: 6px;
  height: 6px;
  border-radius: 50%;
  flex-shrink: 0;
}

.dot-pdf { background-color: #EF4444; box-shadow: 0 0 6px rgba(239, 68, 68, 0.5); }
.dot-epub { background-color: #0EA5E9; box-shadow: 0 0 6px rgba(14, 165, 233, 0.5); }
.dot-mobi { background-color: #F59E0B; box-shadow: 0 0 6px rgba(245, 158, 11, 0.5); }

/* Secondary Meta & Status Filter Row */
.meta-filter-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 2px;
}

.library-summary-text {
  font-size: 12px;
  color: var(--text-tertiary);
  font-weight: 600;
  white-space: nowrap;
}

.status-filter-pills {
  display: flex;
  align-items: center;
  gap: 6px;
}

.status-pill-btn {
  background: transparent;
  border: 1px solid var(--border-hairline);
  color: var(--text-secondary);
  font-size: 12px;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  gap: 4px;
  cursor: pointer;
  transition: all var(--duration-fast);
}

.status-pill-btn:active {
  transform: scale(0.95);
}

.status-pill-btn.active {
  background: var(--accent-light);
  border-color: var(--accent-crimson);
  color: var(--accent-crimson);
}

.status-indicator-dot {
  width: 5px;
  height: 5px;
  border-radius: 50%;
  background-color: var(--accent-crimson);
}

.status-star-icon {
  font-size: 11px;
  line-height: 1;
}

/* Library Scroll Pane */
.library-scroll-pane {
  flex: 1;
  overflow-y: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  padding: 18px 20px calc(80px + env(safe-area-inset-bottom, 16px)) 20px;
  display: flex;
  flex-direction: column;
  gap: 22px;
}

.library-scroll-pane::-webkit-scrollbar {
  display: none;
}

/* Spotlight Hero Book */
.editorial-spotlight {
  display: flex;
  flex-direction: column;
  gap: 10px;
}

.spotlight-badge-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.spotlight-label {
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 1px;
  text-transform: uppercase;
  color: var(--accent-crimson);
}

.reading-velocity {
  font-size: 11px;
  color: var(--text-tertiary);
}

.hero-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-lg);
  padding: 16px;
  display: flex;
  gap: 16px;
  box-shadow: var(--shadow-card);
  cursor: pointer;
  transition: transform var(--duration-fast) var(--ease-spring);
}

.hero-card:active {
  transform: scale(0.98);
}

.hero-cover-spine {
  width: 90px;
  height: 132px;
  flex-shrink: 0;
  border-radius: 6px 10px 10px 6px;
  overflow: hidden;
  box-shadow: 
    -3px 5px 14px rgba(0, 0, 0, 0.22),
    inset -1px 0 3px rgba(255, 255, 255, 0.15),
    inset 3px 0 5px rgba(0, 0, 0, 0.35);
  position: relative;
}

.book-cover-art {
  width: 100%;
  height: 100%;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 8px;
  position: relative;
}

.cover-meditations {
  background: linear-gradient(135deg, #1C1917, #44403C);
  border-left: 2px solid #D97706;
}

.cover-architecture {
  background: linear-gradient(135deg, #0F172A, #334155);
  border-left: 2px solid #38BDF8;
}

.cover-neural {
  background: linear-gradient(135deg, #7F1D1D, #991B1B);
  border-left: 2px solid #F59E0B;
}

.cover-novel {
  background: linear-gradient(135deg, #2E1065, #581C87);
  border-left: 2px solid #C084FC;
}

.cover-format-tag {
  font-size: 10.5px;
  font-weight: 700;
  background: rgba(0, 0, 0, 0.65);
  color: #FFFFFF;
  padding: 3px 6px;
  border-radius: var(--radius-xs);
  align-self: flex-start;
  backdrop-filter: blur(4px);
}

.cover-emboss {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  color: rgba(255, 255, 255, 0.9);
}

.cover-roman {
  font-family: var(--font-display);
  font-size: 32px;
  font-weight: 700;
  line-height: 1;
}

.cover-subline {
  font-size: 10px;
  letter-spacing: 1.5px;
  font-weight: 600;
  margin-top: 2px;
}

.hero-details {
  flex: 1;
  display: flex;
  flex-direction: column;
  justify-content: space-between;
}

.hero-header-line {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.hero-title {
  font-family: var(--font-display);
  font-size: 17px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.25;
}

.format-pill {
  font-size: 10.5px;
  font-weight: 700;
  color: var(--accent-crimson);
  background: var(--accent-light);
  padding: 2px 7px;
  border-radius: var(--radius-xs);
}

.hero-author {
  font-size: 13px;
  color: var(--text-secondary);
  margin-top: 2px;
}

.hero-chapter-peek {
  font-size: 12px;
  color: var(--text-tertiary);
  font-style: italic;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  margin-top: 2px;
}

.metric-container {
  margin: 6px 0;
}

.metric-track {
  width: 100%;
  height: 5px;
  background: var(--bg-elevated);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.metric-fill {
  height: 100%;
  background: var(--accent-crimson);
  border-radius: var(--radius-full);
}

.metric-labels {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  color: var(--text-tertiary);
  margin-top: 4px;
}

.metric-pct {
  font-weight: 700;
  color: var(--accent-crimson);
}

.action-resume-button {
  background: var(--accent-crimson);
  border: none;
  color: #FFFFFF;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
}

/* Visual Comfort Banner */
.comfort-banner {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: 12px 14px;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
}

.comfort-icon-box {
  width: 34px;
  height: 34px;
  background: var(--accent-light);
  color: var(--accent-crimson);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  flex-shrink: 0;
}

.comfort-text-group {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.comfort-heading {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--text-primary);
}

.comfort-sub {
  font-size: 10.5px;
  color: var(--text-tertiary);
  margin-top: 1px;
}

.comfort-action-arrow {
  font-size: 11px;
  font-weight: 700;
  color: var(--accent-crimson);
}

/* Shelf Section Grid */
.shelf-section {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.section-title-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.shelf-heading {
  font-size: 15px;
  font-weight: 700;
  letter-spacing: -0.2px;
}

.shelf-counter {
  font-size: 11px;
  color: var(--text-tertiary);
}

.catalogue-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: 14px;
}

.catalogue-item {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: 10px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  cursor: pointer;
  transition: transform var(--duration-fast);
}

.catalogue-item:active {
  transform: scale(0.97);
}

.cover-thumbnail {
  width: 100%;
  aspect-ratio: 3/4.2;
  border-radius: 6px 8px 8px 6px;
  position: relative;
  overflow: hidden;
  box-shadow: -2px 4px 10px rgba(0, 0, 0, 0.16);
  display: flex;
  flex-direction: column;
  justify-content: space-between;
  padding: 8px;
}

.thumbnail-badge {
  font-size: 10.5px;
  font-weight: 700;
  background: rgba(0, 0, 0, 0.5);
  color: #FFFFFF;
  padding: 3px 6px;
  border-radius: var(--radius-xs);
  align-self: flex-start;
  letter-spacing: 0.3px;
}

.thumbnail-badge.badge-pdf {
  background: #DC2626;
  color: #FFFFFF;
}

.thumbnail-badge.badge-epub {
  background: #0284C7;
  color: #FFFFFF;
}

.thumbnail-badge.badge-mobi {
  background: #D97706;
  color: #FFFFFF;
}

.thumbnail-progress {
  font-size: 11px;
  font-weight: 700;
  background: rgba(0, 0, 0, 0.65);
  color: #FFFFFF;
  padding: 2px 7px;
  border-radius: var(--radius-full);
  align-self: flex-end;
  backdrop-filter: blur(4px);
}

.item-meta {
  display: flex;
  flex-direction: column;
  gap: 2px;
}

.item-title {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  color: var(--text-primary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.item-author {
  font-size: 12.5px;
  color: var(--text-secondary);
}

.item-stats {
  font-size: 11.5px;
  color: var(--text-tertiary);
  margin-top: 2px;
}

/* Native Bottom Navigation Dock */
.native-bottom-dock {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  height: calc(56px + env(safe-area-inset-bottom, 12px));
  padding-bottom: max(10px, env(safe-area-inset-bottom, 12px));
  background: var(--dock-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  border-top: 1px solid var(--border-hairline);
  display: flex;
  align-items: center;
  justify-content: space-around;
  padding-left: 8px;
  padding-right: 8px;
  z-index: 50;
}

.dock-tab {
  background: none;
  border: none;
  color: var(--text-tertiary);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 3px;
  font-size: 11px;
  font-weight: 600;
  cursor: pointer;
  padding: 4px 10px;
  border-radius: var(--radius-sm);
  transition: color var(--duration-fast);
}

.dock-tab.active {
  color: var(--accent-crimson);
}

.dock-center-action {
  background: linear-gradient(135deg, var(--accent-crimson), #7F1D1D);
  border: none;
  color: #FFFFFF;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  box-shadow: 0 4px 14px rgba(153, 27, 27, 0.4);
  transform: translateY(-12px);
  transition: transform var(--duration-fast) var(--ease-spring);
}

.dock-center-action:active {
  transform: translateY(-10px) scale(0.94);
}

/* ==========================================================================
   SCREEN 2: READING SANCTUARY (PURE IMMERSION)
   ========================================================================== */

.reading-viewport-canvas {
  flex: 1;
  background-color: var(--read-bg);
  position: relative;
  overflow: hidden;
  display: flex;
  justify-content: center;
}

.editorial-page-wrap {
  width: 100%;
  height: 100%;
  overflow-y: auto;
  scrollbar-width: none;
  -webkit-overflow-scrolling: touch;
  padding: calc(64px + env(safe-area-inset-top, 12px)) 20px calc(80px + env(safe-area-inset-bottom, 16px)) 20px;
  display: flex;
  flex-direction: column;
  font-family: var(--read-font-family);
  font-size: var(--read-font-size);
  line-height: var(--read-line-height);
  color: var(--read-text);
  user-select: text;
}

.editorial-page-wrap::-webkit-scrollbar {
  display: none;
}

.editorial-chapter-header {
  margin-bottom: 26px;
  text-align: center;
  user-select: none;
}

.chapter-series-tag {
  font-family: var(--font-sans);
  font-size: 10px;
  font-weight: 700;
  letter-spacing: 2px;
  color: var(--accent-crimson);
  text-transform: uppercase;
}

.editorial-headline {
  font-family: var(--font-display);
  font-size: 1.45em;
  font-weight: 700;
  margin-top: 10px;
  line-height: 1.3;
  color: var(--read-text);
}

.ornamental-glyph {
  color: var(--accent-crimson);
  font-size: 11px;
  letter-spacing: 4px;
  margin-top: 12px;
  opacity: 0.75;
}

.reading-prose-container {
  display: flex;
  flex-direction: column;
  gap: 1.25em;
}

.prose-p {
  text-align: left;
  text-wrap: pretty;
  hyphens: auto;
  letter-spacing: -0.01em;
}

.editorial-pullquote {
  background: var(--read-quote-bg);
  border-left: 3px solid var(--accent-crimson);
  padding: 14px 18px;
  border-radius: var(--radius-sm);
  font-style: italic;
  margin: 8px 0;
  line-height: 1.6;
}

.editorial-page-footer {
  margin-top: 48px;
  padding-top: 14px;
  border-top: 1px solid var(--border-hairline);
  font-family: var(--font-sans);
  font-size: 11px;
  color: var(--text-tertiary);
  display: flex;
  justify-content: space-between;
  user-select: none;
}

/* Tap Zones */
.tap-zone {
  position: absolute;
  top: 60px;
  bottom: 80px;
  z-index: 10;
  cursor: pointer;
}

.zone-left { left: 0; width: 25%; }
.zone-center { left: 25%; right: 25%; }
.zone-right { right: 0; width: 25%; }

/* Floating Reader HUD (Glassmorphism) */
.reader-floating-hud {
  position: absolute;
  left: 0;
  right: 0;
  background: var(--dock-bg);
  backdrop-filter: blur(20px) saturate(180%);
  -webkit-backdrop-filter: blur(20px) saturate(180%);
  z-index: 60;
  transition: transform var(--duration-norm) var(--ease-spring), opacity var(--duration-norm) ease;
  opacity: 0;
  pointer-events: none;
}

.reader-floating-hud.visible {
  opacity: 1;
  pointer-events: auto;
  transform: translateY(0);
}

.top-hud {
  top: 0;
  height: calc(56px + env(safe-area-inset-top, 10px));
  padding-top: env(safe-area-inset-top, 10px);
  padding-left: 14px;
  padding-right: 14px;
  border-bottom: 1px solid var(--border-hairline);
  display: flex;
  align-items: center;
  justify-content: space-between;
  transform: translateY(-100%);
}

.bottom-hud {
  bottom: 0;
  border-top: 1px solid var(--border-hairline);
  padding: 10px 18px max(14px, env(safe-area-inset-bottom, 12px)) 18px;
  display: flex;
  flex-direction: column;
  gap: 8px;
  transform: translateY(100%);
}

.hud-circle-btn {
  background: none;
  border: none;
  color: var(--text-secondary);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-full);
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.hud-circle-btn:active {
  background: var(--bg-elevated);
}

.icon-bookmark.active {
  fill: var(--accent-crimson);
  stroke: var(--accent-crimson);
}

.hud-book-identification {
  display: flex;
  flex-direction: column;
  align-items: center;
  max-width: 200px;
}

.hud-title-line {
  font-family: var(--font-display);
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.hud-subtitle-line {
  font-size: 10px;
  color: var(--text-tertiary);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.hud-action-cluster {
  display: flex;
  align-items: center;
  gap: 2px;
}

/* Scrub Row */
.scrub-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.scrub-count-label {
  font-size: 11px;
  font-weight: 600;
  color: var(--text-tertiary);
  min-width: 44px;
  text-align: center;
}

.scrub-slider-wrap {
  flex: 1;
}

.mobile-slider {
  width: 100%;
  -webkit-appearance: none;
  height: 5px;
  border-radius: var(--radius-full);
  background: var(--border-hairline);
  outline: none;
}

.mobile-slider::-webkit-slider-thumb {
  -webkit-appearance: none;
  width: 16px;
  height: 16px;
  border-radius: 50%;
  background: var(--accent-crimson);
  cursor: pointer;
  box-shadow: 0 1px 4px rgba(0, 0, 0, 0.25);
}

/* Reader Tool Row */
.reader-tool-row {
  display: flex;
  align-items: center;
  justify-content: space-around;
  padding-top: 2px;
}

.reader-tool-pill {
  background: none;
  border: none;
  color: var(--text-secondary);
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  font-size: 10px;
  font-weight: 600;
  cursor: pointer;
  padding: 4px 14px;
  border-radius: var(--radius-sm);
}

.reader-tool-pill:active {
  background: var(--bg-elevated);
}

/* ==========================================================================
   BOTTOM SHEETS (DRAWERS)
   ========================================================================== */

.mobile-sheet {
  position: absolute;
  bottom: 0;
  left: 0;
  right: 0;
  background: var(--bg-surface);
  border-top: 1px solid var(--border-hairline);
  border-radius: var(--radius-xl) var(--radius-xl) 0 0;
  box-shadow: var(--shadow-sheet);
  z-index: 80;
  transform: translateY(100%);
  transition: transform var(--duration-norm) var(--ease-spring);
  padding: 10px 20px max(24px, env(safe-area-inset-bottom, 16px)) 20px;
  display: flex;
  flex-direction: column;
  gap: 16px;
  max-height: 85dvh;
  overflow-y: auto;
}

.mobile-sheet.open {
  transform: translateY(0);
}

.sheet-drag-handle {
  width: 38px;
  height: 4px;
  background: var(--border-strong);
  border-radius: var(--radius-full);
  margin: 0 auto;
}

.sheet-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.sheet-title {
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
}

.sheet-close {
  background: none;
  border: none;
  font-size: 22px;
  color: var(--text-tertiary);
  cursor: pointer;
  line-height: 1;
}

.sheet-content {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.sheet-control-unit {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.unit-label-bar {
  display: flex;
  justify-content: space-between;
  align-items: center;
  font-size: 12px;
  font-weight: 600;
  color: var(--text-secondary);
}

.unit-val {
  font-size: 11px;
  color: var(--accent-crimson);
  font-weight: 700;
}

.stepper-track {
  display: flex;
  align-items: center;
  gap: 12px;
}

.step-btn {
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  color: var(--text-primary);
  padding: 6px 14px;
  border-radius: var(--radius-sm);
  font-weight: 700;
  font-size: 13px;
  cursor: pointer;
}

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

.type-card {
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  color: var(--text-primary);
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  text-align: left;
  cursor: pointer;
  transition: all var(--duration-fast);
}

.type-card.active {
  border-color: var(--accent-crimson);
  background: var(--accent-light);
  color: var(--accent-crimson);
}

.sample-glyph {
  font-size: 14px;
  font-weight: 700;
}

.type-category {
  font-size: 11px;
  color: var(--text-tertiary);
  margin-top: 2px;
}

/* Toggle Switch Card */
.toggle-control-card {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 14px;
  background: var(--bg-elevated);
  border-radius: var(--radius-md);
  border: 1px solid var(--border-hairline);
}

.toggle-desc {
  display: flex;
  flex-direction: column;
  gap: 2px;
  max-width: 80%;
}

.toggle-title {
  font-size: 12.5px;
  font-weight: 700;
}

.toggle-sub {
  font-size: 10px;
  color: var(--text-tertiary);
  line-height: 1.35;
}

.native-switch {
  position: relative;
  display: inline-block;
  width: 44px;
  height: 24px;
}

.native-switch input {
  opacity: 0;
  width: 0;
  height: 0;
}

.switch-puck {
  position: absolute;
  cursor: pointer;
  top: 0; left: 0; right: 0; bottom: 0;
  background-color: var(--border-strong);
  transition: .3s;
  border-radius: var(--radius-full);
}

.switch-puck:before {
  position: absolute;
  content: "";
  height: 18px;
  width: 18px;
  left: 3px;
  bottom: 3px;
  background-color: white;
  transition: .3s;
  border-radius: 50%;
}

input:checked + .switch-puck {
  background-color: var(--accent-crimson);
}

input:checked + .switch-puck:before {
  transform: translateX(20px);
}

/* Palette Options List */
.palette-list {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.palette-option {
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-md);
  padding: 10px 12px;
  display: flex;
  align-items: center;
  gap: 12px;
  cursor: pointer;
  text-align: left;
  transition: all var(--duration-fast);
}

.palette-option.active {
  border-color: var(--accent-crimson);
  background: var(--accent-light);
}

.palette-swatch {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-serif);
  font-size: 15px;
  font-weight: 700;
  flex-shrink: 0;
}

.swatch-parchment { background: #FAF7F0; color: #23211E; border: 1px solid #E4DDCF; }
.swatch-sepia     { background: #EFE6D2; color: #34281B; border: 1px solid #D3C5AB; }
.swatch-obsidian  { background: #0A0B0E; color: #CBD0D8; border: 1px solid #202430; }
.swatch-burgundy  { background: #120A0F; color: #F0E5EC; border: 1px solid #331E2C; }
.swatch-epaper    { background: #EAEAEA; color: #121212; border: 1px solid #B8B8B8; }

.palette-info {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.palette-name {
  font-size: 13px;
  font-weight: 700;
  color: var(--text-primary);
}

.palette-notes {
  font-size: 10px;
  color: var(--text-tertiary);
  margin-top: 1px;
}

.palette-radio {
  width: 16px;
  height: 16px;
  border: 2px solid var(--border-strong);
  border-radius: 50%;
  position: relative;
}

.palette-option.active .palette-radio {
  border-color: var(--accent-crimson);
}

.palette-option.active .palette-radio:after {
  content: "";
  position: absolute;
  top: 2px; left: 2px; right: 2px; bottom: 2px;
  background: var(--accent-crimson);
  border-radius: 50%;
}

/* TOC Sheet */
.toc-scroll-list {
  display: flex;
  flex-direction: column;
  gap: 6px;
  overflow-y: auto;
  max-height: 60vh;
}

.toc-entry {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  cursor: pointer;
}

.toc-entry:active {
  background: var(--bg-elevated);
}

.toc-entry.active {
  background: var(--accent-light);
  border: 1px solid var(--accent-crimson);
}

.toc-roman {
  font-family: var(--font-display);
  font-size: 14px;
  font-weight: 700;
  color: var(--text-tertiary);
  width: 24px;
}

.toc-entry.active .toc-roman {
  color: var(--accent-crimson);
}

.toc-text {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.toc-chapter-title {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-primary);
}

.toc-page-marker {
  font-size: 10px;
  color: var(--text-tertiary);
  margin-top: 1px;
}


/* ==========================================================================
   HAMBURGER BUTTON & SIDE NAVIGATION DRAWER
   ========================================================================== */

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

.hamburger-menu-btn {
  background: var(--bg-elevated);
  border: 1px solid var(--border-hairline);
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 4px;
  cursor: pointer;
  transition: all var(--duration-fast);
  flex-shrink: 0;
}

.hamburger-menu-btn:active {
  transform: scale(0.92);
  background: var(--bg-subtle);
}

.hamburger-bar {
  width: 17px;
  height: 1.8px;
  background-color: var(--text-primary);
  border-radius: var(--radius-full);
  transition: all var(--duration-fast);
}

.hamburger-bar.bar-2 {
  width: 12px;
  align-self: flex-start;
  margin-left: 9px;
}

/* Backdrop Overlay */
.drawer-backdrop {
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.45);
  backdrop-filter: blur(6px);
  -webkit-backdrop-filter: blur(6px);
  z-index: 90;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--duration-norm) ease;
}

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

/* Side Navigation Drawer (Sliding from Left) */
.side-navigation-drawer {
  position: absolute;
  top: 0;
  bottom: 0;
  left: 0;
  width: 82%;
  max-width: 330px;
  background: var(--bg-surface);
  border-right: 1px solid var(--border-hairline);
  box-shadow: 10px 0 35px rgba(0, 0, 0, 0.25);
  z-index: 100;
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform var(--duration-norm) var(--ease-spring);
}

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

/* User Header in Drawer */
.drawer-user-header {
  padding-top: max(20px, env(safe-area-inset-top, 20px));
  padding-left: 20px;
  padding-right: 18px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-hairline);
  background: var(--bg-elevated);
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.user-avatar-row {
  display: flex;
  align-items: center;
  gap: 12px;
}

.user-avatar {
  width: 42px;
  height: 42px;
  border-radius: var(--radius-full);
  background: linear-gradient(135deg, var(--accent-crimson), #7F1D1D);
  color: #FFFFFF;
  font-family: var(--font-display);
  font-size: 16px;
  font-weight: 700;
  display: flex;
  align-items: center;
  justify-content: center;
  box-shadow: 0 3px 10px rgba(153, 27, 27, 0.35);
}

.user-meta {
  flex: 1;
  display: flex;
  flex-direction: column;
}

.user-name {
  font-family: var(--font-display);
  font-size: 15px;
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1.2;
}

.user-status-pill {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.2px;
  color: var(--accent-crimson);
  margin-top: 2px;
}

.drawer-close-icon {
  background: none;
  border: none;
  font-size: 24px;
  color: var(--text-tertiary);
  cursor: pointer;
  line-height: 1;
  padding: 4px;
}

.reading-streak-card {
  background: var(--bg-surface);
  border: 1px solid var(--border-hairline);
  border-radius: var(--radius-sm);
  padding: 10px 12px;
  display: flex;
  align-items: center;
  gap: 10px;
}

.streak-icon {
  font-size: 18px;
}

.streak-data {
  display: flex;
  flex-direction: column;
}

.streak-count {
  font-size: 12.5px;
  font-weight: 700;
  color: var(--text-primary);
}

.streak-sub {
  font-size: 11.5px;
  color: var(--text-tertiary);
  margin-top: 1px;
}

/* Drawer Scrollable Body */
.drawer-scroll-body {
  flex: 1;
  overflow-y: auto;
  scrollbar-width: none;
  padding: 16px 14px;
  display: flex;
  flex-direction: column;
  gap: 20px;
}

.drawer-scroll-body::-webkit-scrollbar {
  display: none;
}

.drawer-nav-group {
  display: flex;
  flex-direction: column;
  gap: 4px;
}

.drawer-group-title {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1.2px;
  color: var(--text-tertiary);
  padding-left: 10px;
  padding-bottom: 6px;
}

.drawer-nav-item {
  background: none;
  border: none;
  color: var(--text-secondary);
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  font-size: 13.5px;
  font-weight: 600;
  cursor: pointer;
  transition: all var(--duration-fast);
  text-align: left;
}

.drawer-nav-item:active {
  background: var(--bg-elevated);
}

.drawer-nav-item.active {
  background: var(--accent-light);
  color: var(--accent-crimson);
}

.drawer-nav-item .item-label {
  flex: 1;
}

.drawer-nav-item .item-count {
  font-size: 11.5px;
  color: var(--text-tertiary);
  font-weight: 700;
}

.drawer-nav-item .item-count.highlight {
  color: var(--accent-crimson);
}

.drawer-nav-item .item-badge {
  font-size: 10.5px;
  font-weight: 800;
  background: var(--bg-elevated);
  padding: 2px 7px;
  border-radius: var(--radius-xs);
}

.shelf-tag-dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
}

/* Quick Theme Swatches inside Drawer */
.drawer-palette-chips {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 6px 10px 10px 10px;
}

.chip-swatch {
  width: 28px;
  height: 28px;
  border-radius: var(--radius-full);
  border: 2px solid transparent;
  cursor: pointer;
  transition: transform var(--duration-fast), box-shadow var(--duration-fast);
}

.chip-swatch:active {
  transform: scale(1.15);
}

.chip-swatch.active {
  box-shadow: 0 0 0 2px var(--bg-surface), 0 0 0 4px var(--accent-crimson);
  transform: scale(1.05);
}

.drawer-setting-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 8px 10px;
}

.setting-col {
  display: flex;
  flex-direction: column;
}

.setting-name {
  font-size: 12.5px;
  font-weight: 600;
  color: var(--text-primary);
}

.setting-desc {
  font-size: 11.5px;
  color: var(--text-tertiary);
}

.native-switch.sm {
  width: 38px;
  height: 20px;
}

.native-switch.sm .switch-puck:before {
  height: 14px;
  width: 14px;
}

.native-switch.sm input:checked + .switch-puck:before {
  transform: translateX(18px);
}

/* Drawer Footer */
.drawer-footer {
  padding: 14px 20px max(18px, env(safe-area-inset-bottom, 16px)) 20px;
  border-top: 1px solid var(--border-hairline);
  background: var(--bg-elevated);
  display: flex;
  flex-direction: column;
  gap: 3px;
}

.version-tag {
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 1px;
  color: var(--text-secondary);
}

.edition-tag {
  font-size: 10.5px;
  color: var(--text-tertiary);
}