/* ==========================================================================
   Arcane Art of Virtue - app.css
   Mobile-first design / Book-style reader
   ========================================================================== */

/* --------------------------------------------------------------------------
   Custom Properties
   -------------------------------------------------------------------------- */
:root {
  /* Brand */
  --color-primary: #1c1c1c;
  --color-primary-light: #333333;
  --color-accent: #910000;
  --color-accent-hover: #5e0000;
  --color-accent-soft: rgba(139, 94, 60, 0.1);

  /* Surfaces */
  --color-bg: #faf9f7;
  --color-surface: #ffffff;
  --color-surface-hover: #f5f3f0;
  --color-surface-active: #eceae6;
  --color-border: #e5e2dc;
  --color-border-light: #eeece8;

  /* Text */
  --color-text: #1c1c1c;
  --color-text-secondary: #5a5652;
  --color-text-tertiary: #8a857e;
  --color-text-inverse: #ffffff;

  /* Section colors */
  --color-part-1: #910000;
  --color-part-2: #910000;
  --color-part-3: #910000;
  --color-part-4: #910000;
  --color-endnotes: #910000;

  /* Typography */
  --font-sans: 'Inter', system-ui, -apple-system, sans-serif;
  --font-serif: 'Merriweather', Georgia, serif;

  /* Spacing */
  --space-xs: 0.25rem;
  --space-sm: 0.5rem;
  --space-md: 1rem;
  --space-lg: 1.5rem;
  --space-xl: 2rem;
  --space-2xl: 3rem;
  --space-3xl: 4rem;

  /* Layout */
  --topbar-height: 3.5rem;
  --bottombar-height: 3.5rem;
  --sidebar-width: 18rem;
  --content-max-width: 42rem;

  /* Transitions */
  --transition-fast: 150ms ease;
  --transition-base: 250ms ease;
  --transition-slow: 350ms ease;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 8px 24px rgba(0, 0, 0, 0.12);
  --shadow-xl: 0 16px 48px rgba(0, 0, 0, 0.16);

  /* Radius */
  --radius-sm: 0.375rem;
  --radius-md: 0.5rem;
  --radius-lg: 0.75rem;
  --radius-xl: 1rem;
  --radius-full: 9999px;
}

/* --------------------------------------------------------------------------
   Reduced Motion
   -------------------------------------------------------------------------- */
@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-text-size-adjust: 100%;
}

body {
  font-family: var(--font-sans);
  background-color: var(--color-bg);
  color: var(--color-text);
  line-height: 1.6;
  min-height: 100dvh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

/* --------------------------------------------------------------------------
   Top Bar
   -------------------------------------------------------------------------- */
.reader__topbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: var(--topbar-height);
  padding: 0 var(--space-md);
  background-color: var(--color-primary);
  color: var(--color-text-inverse);
}

.reader__topbar-left {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  min-width: 0;
}

.reader__topbar-title {
  font-weight: 600;
  font-size: 1.0625rem;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  letter-spacing: -0.01em;
}

.reader__topbar-right {
  display: flex;
  align-items: center;
  gap: var(--space-xs);
}

/* --------------------------------------------------------------------------
   Icon Buttons
   -------------------------------------------------------------------------- */
.reader__icon-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 2.5rem;
  height: 2.5rem;
  border: none;
  border-radius: var(--radius-full);
  background: transparent;
  color: inherit;
  cursor: pointer;
  transition: background-color var(--transition-fast);
  flex-shrink: 0;
}

.reader__icon-btn:hover {
  background-color: rgba(255, 255, 255, 0.12);
}

.reader__icon-btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.reader__icon-btn .material-symbols-outlined {
  font-size: 1.5rem;
}

/* --------------------------------------------------------------------------
   Sidebar
   -------------------------------------------------------------------------- */
.reader__sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  z-index: 200;
  width: var(--sidebar-width);
  max-width: 85vw;
  background-color: var(--color-surface);
  border-right: 1px solid var(--color-border);
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform var(--transition-base);
  overflow: hidden;
}

.reader__sidebar.is-open {
  transform: translateX(0);
}

.reader__sidebar-overlay {
  position: fixed;
  inset: 0;
  z-index: 199;
  background-color: rgba(0, 0, 0, 0.4);
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-base), visibility var(--transition-base);
}

.reader__sidebar-overlay.is-visible {
  opacity: 1;
  visibility: visible;
}

.reader__sidebar-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-md) var(--space-md) var(--space-sm);
  flex-shrink: 0;
}

.reader__sidebar-title {
  font-size: 1rem;
  font-weight: 700;
  color: var(--color-text);
  letter-spacing: -0.02em;
}

.reader__sidebar-close .material-symbols-outlined {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
}

/* TOC */
.reader__toc {
  flex: 1;
  overflow-y: auto;
  padding-bottom: var(--space-xl);
  -webkit-overflow-scrolling: touch;
}

.reader__toc-section {
  border-bottom: 1px solid var(--color-border-light);
}

.reader__toc-section:last-child {
  border-bottom: none;
}

.reader__toc-heading {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  width: 100%;
  padding: var(--space-sm) var(--space-md);
  border: none;
  background: none;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.8125rem;
  font-weight: 700;
  color: var(--color-text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  text-align: left;
  transition: background-color var(--transition-fast);
}

.reader__toc-heading:hover {
  background-color: var(--color-surface-hover);
}

.reader__toc-heading:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
}

.reader__toc-heading::before {
  content: '';
  width: 0.375rem;
  height: 0.375rem;
  border-radius: var(--radius-full);
  flex-shrink: 0;
}

.reader__toc-heading[data-section="part-1"]::before { background-color: var(--color-part-1); }
.reader__toc-heading[data-section="part-2"]::before { background-color: var(--color-part-2); }
.reader__toc-heading[data-section="part-3"]::before { background-color: var(--color-part-3); }
.reader__toc-heading[data-section="part-4"]::before { background-color: var(--color-part-4); }
.reader__toc-heading[data-section="endnotes"]::before { background-color: var(--color-endnotes); }

.reader__toc-heading .material-symbols-outlined {
  font-size: 1.125rem;
  margin-left: auto;
  transform: rotate(0deg);
  transition: transform var(--transition-fast);
}

.reader__toc-heading.is-expanded .material-symbols-outlined {
  transform: rotate(180deg);
}

.reader__toc-list {
  list-style: none;
  display: none;
}

.reader__toc-list.is-expanded {
  display: block;
}

.reader__toc-item {
  display: flex;
  align-items: center;
}

.reader__toc-link {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  width: 100%;
  padding: var(--space-sm) var(--space-md) var(--space-sm) calc(var(--space-md) + 1.25rem);
  border: none;
  background: none;
  cursor: pointer;
  font-family: var(--font-sans);
  font-size: 0.875rem;
  color: var(--color-text);
  text-align: left;
  line-height: 1.4;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.reader__toc-link:hover {
  background-color: var(--color-surface-hover);
  color: var(--color-accent);
}

.reader__toc-link:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
}

.reader__toc-link.is-active {
  background-color: var(--color-accent-soft);
  color: var(--color-accent);
  font-weight: 600;
}

/* --------------------------------------------------------------------------
   Search Overlay
   -------------------------------------------------------------------------- */
.reader__search-overlay {
  position: fixed;
  inset: 0;
  z-index: 300;
  background-color: var(--color-bg);
  display: flex;
  flex-direction: column;
  opacity: 0;
  visibility: hidden;
  transition: opacity var(--transition-fast), visibility var(--transition-fast);
}

.reader__search-overlay[hidden] {
  display: none;
}

.reader__search-overlay.is-open {
  display: flex;
  opacity: 1;
  visibility: visible;
}

.reader__search-bar {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  height: var(--topbar-height);
  padding: 0 var(--space-md);
  background-color: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  flex-shrink: 0;
}

.reader__search-bar-icon {
  color: var(--color-text-tertiary);
  font-size: 1.375rem;
  flex-shrink: 0;
}

.reader__search-input {
  flex: 1;
  border: none;
  outline: none;
  background: none;
  font-family: var(--font-sans);
  font-size: 1rem;
  color: var(--color-text);
  min-width: 0;
}

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

.reader__search-close .material-symbols-outlined {
  font-size: 1.25rem;
  color: var(--color-text-secondary);
}

.reader__search-results {
  flex: 1;
  overflow-y: auto;
  padding: var(--space-md);
  -webkit-overflow-scrolling: touch;
}

.reader__search-empty {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: var(--space-3xl) var(--space-lg);
  text-align: center;
  color: var(--color-text-tertiary);
}

.reader__search-empty .material-symbols-outlined {
  font-size: 3rem;
  margin-bottom: var(--space-md);
  opacity: 0.4;
}

.reader__search-count {
  font-size: 0.8125rem;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-md);
}

.reader__search-item {
  padding: var(--space-md);
  border: 1px solid var(--color-border-light);
  border-radius: var(--radius-md);
  margin-bottom: var(--space-sm);
  cursor: pointer;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.reader__search-item:hover {
  background-color: var(--color-surface-hover);
  border-color: var(--color-border);
}

.reader__search-item:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.reader__search-item-section {
  display: inline-block;
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-tertiary);
  margin-bottom: var(--space-xs);
}

.reader__search-item-title {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-text);
  margin-bottom: var(--space-xs);
}

.reader__search-item-excerpt {
  font-size: 0.8125rem;
  color: var(--color-text-secondary);
  line-height: 1.5;
}

.reader__search-item-excerpt mark {
  background-color: rgba(139, 94, 60, 0.15);
  color: var(--color-accent);
  border-radius: 2px;
  padding: 0 2px;
}

/* --------------------------------------------------------------------------
   Main Content Area
   -------------------------------------------------------------------------- */
.reader__main {
  padding-top: var(--topbar-height);
  padding-bottom: var(--bottombar-height);
  min-height: 100dvh;
}

/* --------------------------------------------------------------------------
   Home Screen
   -------------------------------------------------------------------------- */
.reader__home {
  padding: var(--space-xl) var(--space-md) var(--space-2xl);
  max-width: var(--content-max-width);
  margin: 0 auto;
}

.reader__home-hero {
  text-align: center;
  padding: var(--space-2xl) 0;
}

.reader__home-title {
  font-family: var(--font-serif);
  font-size: 1.875rem;
  font-weight: 700;
  color: var(--color-primary);
  line-height: 1.25;
  margin-bottom: var(--space-xs);
}

.reader__home-subtitle {
  font-family: var(--font-serif);
  font-size: 1rem;
  font-weight: 300;
  font-style: italic;
  color: var(--color-text-secondary);
  margin-bottom: var(--space-lg);
}

.reader__home-desc {
  font-family: var(--font-serif);
  font-size: 0.9375rem;
  color: var(--color-text-secondary);
  line-height: 1.7;
  max-width: 30rem;
  margin: 0 auto;
}

/* Home Actions */
.reader__home-actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-bottom: var(--space-2xl);
}

.reader__btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-sm);
  padding: 0.875rem var(--space-lg);
  border: none;
  border-radius: var(--radius-lg);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color var(--transition-fast), transform var(--transition-fast);
  text-decoration: none;
}

.reader__btn:active {
  transform: scale(0.98);
}

.reader__btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.reader__btn .material-symbols-outlined {
  font-size: 1.25rem;
}

.reader__btn--primary {
  background-color: var(--color-accent);
  color: var(--color-text-inverse);
}

.reader__btn--primary:hover {
  background-color: var(--color-accent-hover);
}

.reader__btn--secondary {
  background-color: var(--color-surface);
  color: var(--color-text);
  border: 1px solid var(--color-border);
}

.reader__btn--secondary:hover {
  background-color: var(--color-surface-hover);
}

.reader__btn--accent {
  background-color: transparent;
  color: var(--color-accent);
  border: 2px solid var(--color-accent);
}

.reader__btn--accent:hover {
  background-color: var(--color-accent);
  color: var(--color-text-inverse);
}

/* Home Section Cards */
.reader__home-sections {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.reader__section-card {
  background-color: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  overflow: hidden;
  transition: border-color var(--transition-fast);
}

.reader__section-card-header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md);
  cursor: pointer;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-family: var(--font-sans);
  transition: background-color var(--transition-fast);
}

.reader__section-card-header:hover {
  background-color: var(--color-surface-hover);
}

.reader__section-card-header:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
}

.reader__section-card-dot {
  width: 0.625rem;
  height: 0.625rem;
  border-radius: var(--radius-full);
  flex-shrink: 0;
}

.reader__section-card-info {
  flex: 1;
  min-width: 0;
  display: flex;
  flex-direction: column;
  gap: 5px;
}

.reader__section-card-title {
  font-size: 0.9375rem;
  font-weight: 600;
  color: var(--color-text);
}

.reader__section-card-count {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
}

.reader__section-card-header .material-symbols-outlined {
  font-size: 1.25rem;
  color: var(--color-text-tertiary);
  transform: rotate(0deg);
  transition: transform var(--transition-fast);
}

.reader__section-card-header.is-expanded .material-symbols-outlined {
  transform: rotate(180deg);
}

.reader__section-card-items {
  display: none;
  list-style: none;
  padding: 0 var(--space-md) var(--space-md);
  border-top: 1px solid var(--color-border-light);
}

.reader__section-card-items.is-expanded {
  display: block;
}

.reader__section-card-link {
  display: block;
  padding: var(--space-sm) 0;
  font-size: 0.875rem;
  color: var(--color-text);
  cursor: pointer;
  border: none;
  background: none;
  width: 100%;
  text-align: left;
  font-family: var(--font-sans);
  transition: color var(--transition-fast);
  line-height: 1.4;
}

.reader__section-card-link:hover {
  color: var(--color-accent);
}

.reader__section-card-link:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* --------------------------------------------------------------------------
   Document View
   -------------------------------------------------------------------------- */
.reader__document {
  max-width: var(--content-max-width);
  margin: 0 auto;
  padding: var(--space-lg) var(--space-md) var(--space-xl);
}

.reader__document-meta {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 1px solid var(--color-border-light);
}

.reader__document-section {
  font-size: 0.75rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.04em;
  color: var(--color-text-tertiary);
}

.reader__document-number {
  font-size: 0.75rem;
  color: var(--color-text-tertiary);
}

.reader__bookmark-btn {
  margin-left: auto;
  color: var(--color-text-tertiary);
  transition: color var(--transition-fast);
}

.reader__bookmark-btn:hover {
  color: var(--color-accent);
}

.reader__bookmark-btn.is-bookmarked {
  color: var(--color-accent);
}

.reader__bookmark-btn.is-bookmarked .material-symbols-outlined {
  font-variation-settings: 'FILL' 1;
}

/* Heading-level bookmark buttons */
.reader__heading-bookmark {
  flex-shrink: 0;
  margin-left: auto;
  background: none;
  border: none;
  cursor: pointer;
  padding: 0.125rem;
  color: var(--color-text-tertiary);
  transition: color var(--transition-fast);
}

.reader__heading-bookmark:hover {
  color: var(--color-accent);
}

.reader__heading-bookmark.is-bookmarked {
  color: var(--color-accent);
}

.reader__heading-bookmark.is-bookmarked .material-symbols-outlined {
  font-variation-settings: 'FILL' 1;
}

.reader__heading-bookmark .material-symbols-outlined {
  font-size: 1.125rem;
}

/* Markdown Body Styles */
.reader__document-body {
  font-family: var(--font-serif);
  font-size: 1.0625rem;
  line-height: 1.85;
  color: var(--color-text);
}

.reader__document-body h1 {
  font-family: var(--font-serif);
  font-size: 1.625rem;
  font-weight: 700;
  line-height: 1.3;
  margin-bottom: var(--space-xl);
  color: var(--color-primary);
  letter-spacing: -0.02em;
}

.reader__document-body h2 {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  font-family: var(--font-sans);
  font-size: 1.1875rem;
  font-weight: 700;
  line-height: 1.35;
  margin-top: var(--space-2xl);
  margin-bottom: var(--space-md);
  color: var(--color-text);
  scroll-margin-top: calc(var(--topbar-height) + var(--space-md));
  letter-spacing: -0.01em;
}

.reader__document-body h3 {
  font-family: var(--font-sans);
  font-size: 1rem;
  font-weight: 600;
  line-height: 1.4;
  margin-top: var(--space-xl);
  margin-bottom: var(--space-sm);
  color: var(--color-text-secondary);
  letter-spacing: 0;
}

.reader__document-body h4 {
  font-family: var(--font-sans);
  font-size: 0.9375rem;
  font-weight: 600;
  margin-top: var(--space-lg);
  margin-bottom: var(--space-sm);
  color: var(--color-text-secondary);
}

.reader__document-body p {
  margin-bottom: var(--space-md);
}

.reader__document-body ul,
.reader__document-body ol {
  margin-bottom: var(--space-md);
  padding-left: var(--space-lg);
}

.reader__document-body li {
  margin-bottom: var(--space-xs);
  line-height: 1.7;
}

.reader__document-body li > ul,
.reader__document-body li > ol {
  margin-top: var(--space-xs);
  margin-bottom: 0;
}

.reader__document-body strong {
  font-weight: 700;
}

.reader__document-body em {
  font-style: italic;
}

.reader__document-body blockquote {
  margin: var(--space-lg) 0;
  padding: var(--space-md) var(--space-lg);
  border-left: 3px solid var(--color-accent);
  background-color: var(--color-surface);
  border-radius: 0 var(--radius-sm) var(--radius-sm) 0;
  font-style: italic;
  color: var(--color-text-secondary);
}

.reader__document-body blockquote p:last-child {
  margin-bottom: 0;
}

.reader__document-body hr {
  margin: var(--space-2xl) 0;
  border: none;
  border-top: 1px solid var(--color-border);
}

.reader__document-body table {
  width: 100%;
  border-collapse: collapse;
  margin: var(--space-lg) 0;
  font-family: var(--font-sans);
  font-size: 0.875rem;
}

.reader__document-body th,
.reader__document-body td {
  padding: var(--space-sm) var(--space-md);
  border: 1px solid var(--color-border);
  text-align: left;
}

.reader__document-body th {
  background-color: var(--color-surface-hover);
  font-weight: 600;
}

.reader__document-body a {
  color: var(--color-accent);
  text-decoration: underline;
  text-decoration-thickness: 1px;
  text-underline-offset: 2px;
  transition: color var(--transition-fast);
}

.reader__document-body a:hover {
  color: var(--color-accent-hover);
}

.reader__document-body a:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

/* --------------------------------------------------------------------------
   Chapter Navigation
   -------------------------------------------------------------------------- */
.reader__chapter-nav {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
  margin-top: var(--space-2xl);
  padding-top: var(--space-xl);
  border-top: 1px solid var(--color-border);
}

.reader__chapter-btn {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-md);
  border: 1px solid var(--color-border);
  border-radius: var(--radius-lg);
  background-color: var(--color-surface);
  cursor: pointer;
  font-family: var(--font-sans);
  text-align: left;
  transition: background-color var(--transition-fast), border-color var(--transition-fast);
}

.reader__chapter-btn:hover {
  background-color: var(--color-surface-hover);
  border-color: var(--color-accent);
}

.reader__chapter-btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: 2px;
}

.reader__chapter-btn:disabled {
  opacity: 0.3;
  pointer-events: none;
}

.reader__chapter-btn .material-symbols-outlined {
  font-size: 1.25rem;
  color: var(--color-text-tertiary);
  flex-shrink: 0;
}

.reader__chapter-btn-text {
  flex: 1;
  min-width: 0;
}

.reader__chapter-btn-label {
  display: block;
  font-size: 0.6875rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.06em;
  color: var(--color-text-tertiary);
  margin-bottom: 0.125rem;
}

.reader__chapter-btn-title {
  display: block;
  font-size: 0.875rem;
  font-weight: 500;
  color: var(--color-text);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.reader__chapter-btn--next {
  text-align: right;
}

.reader__chapter-btn--next .reader__chapter-btn-text {
  order: -1;
}

/* --------------------------------------------------------------------------
   Loading & Error States
   -------------------------------------------------------------------------- */
.reader__loading {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-2xl);
  color: var(--color-text-tertiary);
  font-family: var(--font-sans);
  font-size: 0.9375rem;
}

.reader__loading-spinner {
  width: 1.25rem;
  height: 1.25rem;
  border: 2px solid var(--color-border);
  border-top-color: var(--color-accent);
  border-radius: var(--radius-full);
  animation: spin 0.7s linear infinite;
}

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

.reader__error {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: var(--space-md);
  padding: var(--space-3xl) var(--space-lg);
  text-align: center;
  color: var(--color-text-secondary);
  font-family: var(--font-sans);
}

.reader__error .material-symbols-outlined {
  font-size: 2.5rem;
  color: var(--color-text-tertiary);
}

/* --------------------------------------------------------------------------
   Bottom Bar (Mobile)
   -------------------------------------------------------------------------- */
.reader__bottombar {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 100;
  display: flex;
  align-items: center;
  justify-content: space-around;
  height: var(--bottombar-height);
  background-color: var(--color-surface);
  border-top: 1px solid var(--color-border);
  padding-bottom: env(safe-area-inset-bottom, 0);
}

.reader__bottombar-btn {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.125rem;
  border: none;
  background: none;
  color: var(--color-text-tertiary);
  cursor: pointer;
  padding: var(--space-xs) var(--space-sm);
  min-width: 3rem;
  font-family: var(--font-sans);
  transition: color var(--transition-fast);
}

.reader__bottombar-btn:hover {
  color: var(--color-accent);
}

.reader__bottombar-btn:focus-visible {
  outline: 2px solid var(--color-accent);
  outline-offset: -2px;
}

.reader__bottombar-btn:disabled {
  opacity: 0.3;
  pointer-events: none;
}

.reader__bottombar-btn.is-active {
  color: var(--color-accent);
}

.reader__bottombar-btn .material-symbols-outlined {
  font-size: 1.375rem;
}

.reader__bottombar-label {
  font-size: 0.625rem;
  font-weight: 600;
  letter-spacing: 0.02em;
  text-transform: uppercase;
}

/* --------------------------------------------------------------------------
   Desktop Layout
   -------------------------------------------------------------------------- */
@media (min-width: 1024px) {
  .reader__sidebar {
    transform: translateX(0);
    position: fixed;
    top: var(--topbar-height);
    box-shadow: none;
  }

  .reader__sidebar-overlay {
    display: none;
  }

  .reader__sidebar-close {
    display: none;
  }

  .reader__main {
    padding-left: var(--sidebar-width);
    padding-bottom: 0;
  }

  .reader__bottombar {
    display: none;
  }

  .reader__home {
    padding: var(--space-2xl) var(--space-xl) var(--space-3xl);
  }

  .reader__home-title {
    font-size: 2.5rem;
  }

  .reader__home-actions {
    flex-direction: row;
    justify-content: center;
  }

  .reader__btn {
    min-width: 10rem;
  }

  .reader__chapter-nav {
    flex-direction: row;
  }

  .reader__chapter-btn {
    flex: 1;
  }

  .reader__document {
    padding: var(--space-2xl) var(--space-2xl) var(--space-3xl);
  }
}