/* ============================================
   Reading Copilot — Analog Office Style System
   ============================================ */

/* --- Google Fonts --- */
@import url('https://fonts.googleapis.com/css2?family=Noto+Serif+SC:wght@400;600;700&family=IBM+Plex+Mono:wght@400;500&display=swap');

/* --- Design Tokens --- */
:root {
  /* Background */
  --color-bg-paper: #F0F0ED;
  --color-bg-paper-warm: #E2DED7;
  --color-bg-folder: #CED4B0;
  --color-bg-card: #FBFBFB;

  /* Primary */
  --color-primary-blue: #395CC5;
  --color-primary-blue-dark: #2547A8;
  --color-primary-blue-light: #6F8AE0;

  /* Text */
  --color-text-primary: #1F2121;
  --color-text-heading: #111111;
  --color-text-secondary: #424348;
  --color-text-muted: #6E6F75;
  --color-text-disabled: #C9C9C9;

  /* Line & Border */
  --color-line-paper: #B3B3B6;
  --color-border-soft: #D6D3CC;
  --color-border-dark: #2A2A2A;

  /* Shadow / Texture */
  --color-shadow-paper: rgba(31, 33, 33, 0.18);
  --color-scan-noise: #8F9096;

  /* Spacing */
  --touch-target: 44px;
  --spacing-xs: 4px;
  --spacing-sm: 8px;
  --spacing-md: 16px;
  --spacing-lg: 24px;
  --spacing-xl: 32px;

  /* Typography */
  --font-serif: 'Noto Serif SC', 'Songti SC', serif;
  --font-mono: 'IBM Plex Mono', 'SF Mono', monospace;
  --font-size-xs: 11px;
  --font-size-sm: 13px;
  --font-size-base: 15px;
  --font-size-lg: 18px;
  --font-size-xl: 22px;
  --font-size-2xl: 28px;
  --line-height: 1.75;

  /* Animation */
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s ease;

  /* Layout */
  --topbar-height: 48px;
  --panel-width: 320px;

  /* Safe Area */
  --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);
}

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

html {
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

body {
  font-family: var(--font-serif);
  font-size: var(--font-size-base);
  line-height: var(--line-height);
  color: var(--color-text-primary);
  background-color: var(--color-bg-paper);
  overflow: hidden;
  height: 100vh;
  height: 100dvh;
  /* Paper texture via CSS noise */
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 256 256' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.9' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)' opacity='0.03'/%3E%3C/svg%3E");
}

a {
  color: var(--color-primary-blue);
  text-decoration: none;
}

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

/* Custom scrollbar */
::-webkit-scrollbar {
  width: 6px;
}
::-webkit-scrollbar-track {
  background: transparent;
}
::-webkit-scrollbar-thumb {
  background: var(--color-border-soft);
  border-radius: 3px;
}

/* Selection */
::selection {
  background: rgba(57, 92, 197, 0.15);
  color: var(--color-text-heading);
}

/* ============================================
   Layout — App Shell
   ============================================ */

.app {
  display: flex;
  flex-direction: column;
  height: 100vh;
  height: 100dvh;
}

/* --- Top Bar --- */
.topbar {
  display: flex;
  align-items: center;
  height: var(--topbar-height);
  padding: 0 var(--spacing-lg);
  padding-top: var(--safe-top);
  border-bottom: 1px solid var(--color-line-paper);
  background: var(--color-bg-paper);
  flex-shrink: 0;
  z-index: 100;
}

.topbar__logo {
  font-family: var(--font-serif);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-text-heading);
  letter-spacing: -0.01em;
}

.topbar__actions {
  display: flex;
  align-items: center;
  gap: var(--spacing-md);
  margin-left: auto;
}

/* File picker button — small folder icon */
.btn-file {
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--touch-target);
  height: var(--touch-target);
  border-radius: 6px;
  color: var(--color-text-secondary);
  transition: background var(--transition-fast);
  position: relative;
}

.btn-file:active {
  background: var(--color-bg-paper-warm);
}

.btn-file svg {
  width: 22px;
  height: 22px;
}

.btn-file input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

/* Nav links */
.topbar__nav {
  display: flex;
  align-items: center;
  gap: var(--spacing-xs);
}

/* Book title — stamp style */
.book-title {
  padding: var(--spacing-sm) var(--spacing-lg);
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-text-heading);
  font-family: var(--font-serif);
  border-bottom: 1px solid var(--color-border-soft);
  background: var(--color-bg-paper);
  flex-shrink: 0;
}

.nav-link {
  display: flex;
  align-items: center;
  height: var(--touch-target);
  padding: 0 var(--spacing-md);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  border-radius: 6px;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

.nav-link:active {
  background: var(--color-bg-paper-warm);
}

.nav-link.active {
  color: var(--color-primary-blue);
  font-weight: 600;
}

/* ============================================
   Layout — Main Content (Reader Page)
   ============================================ */

.main {
  display: flex;
  flex: 1;
  overflow: hidden;
  position: relative;
}

/* --- Reader Pane (Left) --- */
.reader-pane {
  flex: 1;
  display: flex;
  flex-direction: column;
  overflow: hidden;
  position: relative;
}

.reader-container {
  flex: 1;
  overflow: hidden;
  position: relative;
}

/* epub.js render area */
#epub-viewer {
  width: 100%;
  height: 100%;
}

/* --- Pagination Controls --- */
.pagination {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--spacing-lg);
  padding: var(--spacing-sm) var(--spacing-md);
  padding-bottom: calc(var(--spacing-sm) + var(--safe-bottom));
  border-top: 1px solid var(--color-line-paper);
  background: var(--color-bg-paper);
  flex-shrink: 0;
}

.pagination__btn {
  display: flex;
  align-items: center;
  justify-content: center;
  width: var(--touch-target);
  height: var(--touch-target);
  border-radius: 6px;
  color: var(--color-text-secondary);
  font-size: var(--font-size-lg);
  transition: all var(--transition-fast);
  user-select: none;
}

.pagination__btn:active {
  background: var(--color-bg-paper-warm);
  color: var(--color-primary-blue);
}

.pagination__info-container {
  display: flex;
  align-items: center;
  gap: var(--spacing-sm);
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
}

.chapter-info {
  color: var(--color-text-secondary);
  font-family: var(--font-serif);
  max-width: 150px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.progress-input {
  width: 44px;
  height: 28px;
  background: var(--color-bg-paper-warm);
  border: 1px solid var(--color-border-soft);
  border-radius: 4px;
  font-family: var(--font-mono);
  font-size: var(--font-size-sm);
  color: var(--color-text-heading);
  text-align: center;
  outline: none;
  transition: border-color var(--transition-fast);
}

.progress-input:focus {
  border-color: var(--color-primary-blue);
}

.progress-percent {
  margin-left: -4px;
}

/* ============================================
   Character Panel (Right Side)
   ============================================ */

.character-panel {
  position: absolute;
  top: 0;
  right: 0;
  width: var(--panel-width);
  height: 100%;
  background: var(--color-bg-paper-warm);
  border-left: 1px solid var(--color-line-paper);
  box-shadow: -4px 0 12px var(--color-shadow-paper);
  transform: translateX(100%);
  transition: transform var(--transition-normal);
  z-index: 50;
  overflow-y: auto;
  display: flex;
  flex-direction: column;
}

.character-panel.open {
  transform: translateX(0);
}

.character-panel__header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--spacing-lg);
  border-bottom: 1px solid var(--color-border-soft);
  flex-shrink: 0;
}

.character-panel__name {
  font-size: var(--font-size-xl);
  font-weight: 700;
  color: var(--color-text-heading);
}

.character-panel__close {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: 50%;
  color: var(--color-text-muted);
  font-size: var(--font-size-lg);
  transition: background var(--transition-fast);
}

.character-panel__close:active {
  background: var(--color-bg-paper);
}

.character-panel__body {
  padding: var(--spacing-lg);
  flex: 1;
}

.character-panel__stats {
  display: flex;
  gap: var(--spacing-md);
  margin-bottom: var(--spacing-lg);
}

.stat-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--spacing-xs);
  padding: var(--spacing-xs) var(--spacing-sm);
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-soft);
  border-radius: 4px;
  font-size: var(--font-size-xs);
  font-family: var(--font-mono);
  color: var(--color-text-secondary);
}

.stat-badge--blue {
  background: rgba(57, 92, 197, 0.08);
  border-color: rgba(57, 92, 197, 0.2);
  color: var(--color-primary-blue);
}

.character-panel__summary {
  font-size: var(--font-size-base);
  line-height: var(--line-height);
  color: var(--color-text-primary);
  margin-bottom: var(--spacing-lg);
}

.character-panel__section-title {
  font-size: var(--font-size-sm);
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-sm);
}

.character-panel__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
  margin-bottom: var(--spacing-lg);
}

.tag {
  display: inline-block;
  padding: 2px var(--spacing-sm);
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-soft);
  border-radius: 3px;
  font-size: var(--font-size-xs);
  color: var(--color-text-secondary);
}

.tag--blue {
  background: rgba(57, 92, 197, 0.08);
  border-color: rgba(57, 92, 197, 0.2);
  color: var(--color-primary-blue);
}

/* Related characters list */
.related-list {
  list-style: none;
}

.related-list li {
  padding: var(--spacing-sm) 0;
  border-bottom: 1px solid var(--color-border-soft);
  font-size: var(--font-size-sm);
  color: var(--color-text-secondary);
  cursor: pointer;
}

.related-list li:last-child {
  border-bottom: none;
}

.related-list li .name {
  color: var(--color-primary-blue);
  font-weight: 600;
}

/* ============================================
   Character Name Highlight (in EPUB text)
   ============================================ */

.character-name {
  color: var(--color-primary-blue);
  text-decoration: underline;
  text-decoration-color: rgba(57, 92, 197, 0.3);
  text-underline-offset: 3px;
  cursor: pointer;
  transition: text-decoration-color var(--transition-fast);
}

.character-name:active {
  text-decoration-color: var(--color-primary-blue);
}

/* ============================================
   Upload / Empty State
   ============================================ */

.empty-state {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  gap: var(--spacing-lg);
  padding: var(--spacing-xl);
}

.empty-state__folder {
  width: 80px;
  height: 64px;
  position: relative;
}

/* CSS-only folder icon */
.folder-icon {
  position: relative;
  width: 80px;
  height: 56px;
}

.folder-icon__tab {
  position: absolute;
  top: 0;
  left: 8px;
  width: 28px;
  height: 12px;
  background: var(--color-bg-folder);
  border-radius: 4px 4px 0 0;
  border: 1px solid var(--color-border-soft);
  border-bottom: none;
}

.folder-icon__body {
  position: absolute;
  top: 10px;
  left: 0;
  width: 80px;
  height: 46px;
  background: var(--color-bg-folder);
  border-radius: 0 6px 6px 6px;
  border: 1px solid var(--color-border-soft);
  box-shadow: 2px 3px 0 var(--color-shadow-paper);
}

.empty-state__text {
  font-size: var(--font-size-base);
  color: var(--color-text-muted);
  text-align: center;
}

.empty-state__hint {
  font-size: var(--font-size-xs);
  color: var(--color-text-disabled);
  font-family: var(--font-mono);
}

.btn-primary {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  height: var(--touch-target);
  padding: 0 var(--spacing-lg);
  background: var(--color-primary-blue);
  color: #fff;
  font-size: var(--font-size-sm);
  font-family: var(--font-serif);
  font-weight: 600;
  border-radius: 6px;
  transition: background var(--transition-fast);
  position: relative;
  overflow: hidden;
}

.btn-primary:active {
  background: var(--color-primary-blue-dark);
}

.btn-primary input[type="file"] {
  position: absolute;
  inset: 0;
  opacity: 0;
  cursor: pointer;
}

/* ============================================
   Loading State
   ============================================ */

.loading {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  height: 100%;
  gap: var(--spacing-md);
}

.loading__dots {
  display: flex;
  gap: var(--spacing-sm);
}

.loading__dot {
  width: 6px;
  height: 6px;
  background: var(--color-text-muted);
  border-radius: 50%;
  animation: dot-bounce 1.2s ease-in-out infinite;
}

.loading__dot:nth-child(2) { animation-delay: 0.15s; }
.loading__dot:nth-child(3) { animation-delay: 0.3s; }

@keyframes dot-bounce {
  0%, 80%, 100% { transform: scale(0.6); opacity: 0.4; }
  40% { transform: scale(1); opacity: 1; }
}

.loading__text {
  font-size: var(--font-size-sm);
  color: var(--color-text-muted);
  font-family: var(--font-mono);
}

/* ============================================
   Characters Page (characters.html)
   ============================================ */

.characters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(200px, 1fr));
  gap: var(--spacing-lg);
  padding: var(--spacing-lg);
  overflow-y: auto;
  flex: 1;
}

.character-card {
  background: var(--color-bg-paper-warm);
  border: 1px solid var(--color-border-soft);
  border-radius: 4px;
  padding: var(--spacing-lg);
  position: relative;
  box-shadow: 2px 3px 0 var(--color-shadow-paper);
  cursor: pointer;
  transition: box-shadow var(--transition-fast);
  /* Slight rotation for analog feel */
  transform: rotate(-0.5deg);
}

.character-card:nth-child(even) {
  transform: rotate(0.5deg);
}

.character-card:nth-child(3n) {
  transform: rotate(0.8deg);
}

.character-card:active {
  box-shadow: 1px 2px 0 var(--color-shadow-paper);
}

/* Pushpin decoration */
.character-card::before {
  content: '';
  position: absolute;
  top: -4px;
  left: 50%;
  transform: translateX(-50%);
  width: 10px;
  height: 10px;
  background: var(--color-text-secondary);
  border-radius: 50%;
  border: 2px solid var(--color-bg-paper-warm);
  box-shadow: 0 1px 2px var(--color-shadow-paper);
}

.character-card__name {
  font-size: var(--font-size-lg);
  font-weight: 700;
  color: var(--color-text-heading);
  margin-bottom: var(--spacing-sm);
}

.character-card__count {
  font-size: var(--font-size-xs);
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-sm);
}

.character-card__tags {
  display: flex;
  flex-wrap: wrap;
  gap: var(--spacing-xs);
}

/* ============================================
   Character Detail Modal
   ============================================ */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(31, 33, 33, 0.3);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-normal);
}

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

.modal {
  background: var(--color-bg-paper);
  border: 1px solid var(--color-border-soft);
  border-radius: 8px;
  box-shadow: 4px 6px 0 var(--color-shadow-paper);
  width: min(90vw, 560px);
  max-height: 80vh;
  overflow-y: auto;
  padding: var(--spacing-xl);
}

.modal__title {
  font-size: var(--font-size-2xl);
  font-weight: 700;
  color: var(--color-text-heading);
  margin-bottom: var(--spacing-md);
}

.modal__section {
  margin-bottom: var(--spacing-lg);
}

.modal__section-title {
  font-size: var(--font-size-sm);
  font-family: var(--font-mono);
  color: var(--color-text-muted);
  letter-spacing: 0.05em;
  margin-bottom: var(--spacing-sm);
  padding-bottom: var(--spacing-xs);
  border-bottom: 1px solid var(--color-line-paper);
}

.modal__close {
  position: absolute;
  top: var(--spacing-md);
  right: var(--spacing-md);
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: 50%;
  color: var(--color-text-muted);
  font-size: var(--font-size-lg);
}

/* Paragraph excerpt in modal */
.excerpt {
  padding: var(--spacing-md);
  background: var(--color-bg-paper-warm);
  border-left: 3px solid var(--color-primary-blue);
  margin-bottom: var(--spacing-sm);
  font-size: var(--font-size-sm);
  line-height: var(--line-height);
  color: var(--color-text-secondary);
  border-radius: 0 4px 4px 0;
}

.excerpt__chapter {
  font-family: var(--font-mono);
  font-size: var(--font-size-xs);
  color: var(--color-text-muted);
  margin-bottom: var(--spacing-xs);
}

/* ============================================
   Responsive — iPad mini 7 (744px viewport)
   ============================================ */

@media (max-width: 744px) {
  :root {
    --panel-width: 85vw;
  }

  .topbar__logo {
    font-size: var(--font-size-base);
  }

  .characters-grid {
    grid-template-columns: repeat(2, 1fr);
  }
}

@media (max-width: 480px) {
  :root {
    --panel-width: 100vw;
  }

  .topbar {
    padding: 0 var(--spacing-md);
  }
}