/* ==========================================================================
   ANIMAL FARM MOBILE-FIRST E-READER & BOOK REPORT STUDIO
   Design Aesthetics: Apple Books / Kindle Serene Minimalist Style
   ========================================================================== */

/* --- CSS Variables & Color Themes --- */
:root {
  --font-serif: "Merriweather", Georgia, "Newsreader", serif;
  --font-sans: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, sans-serif;
  
  --line-height-reader: 1.85;
  --max-content-width: 65ch;
  --header-height: 56px;
  --bottom-nav-height: 60px;
  --radius-sm: 6px;
  --radius-md: 10px;
  --radius-lg: 16px;
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s cubic-bezier(0.16, 1, 0.3, 1);
  --shadow-sm: 0 1px 3px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 16px rgba(0, 0, 0, 0.08);
  --shadow-lg: 0 12px 32px rgba(0, 0, 0, 0.12);
}

/* 1. SEPIA THEME (Default) */
body.theme-sepia {
  --bg-app: #FBF7F0;
  --bg-page: #F4ECD8;
  --bg-card: #FAF3E3;
  --bg-subtle: #EFE6CD;
  --text-main: #2C2621;
  --text-muted: #7A6F64;
  --text-faint: #A3978B;
  --border-color: #E2D7C2;
  --border-subtle: #EADFCB;
  --accent: #A65D37;
  --accent-hover: #8F4C29;
  --accent-light: #F2E4D8;
  --highlight-bg: #F3D078;
  --highlight-text: #2C2621;
  --highlight-border: #D8B24C;
  --badge-green-bg: #D4EDDA;
  --badge-green-text: #155724;
}

/* 2. LIGHT THEME (Day) */
body.theme-light {
  --bg-app: #F7F7F5;
  --bg-page: #FFFFFF;
  --bg-card: #FAFAFA;
  --bg-subtle: #EFEFEF;
  --text-main: #1F2328;
  --text-muted: #57606A;
  --text-faint: #8C959F;
  --border-color: #D0D7DE;
  --border-subtle: #E6E4DD;
  --accent: #3E5C76;
  --accent-hover: #2B4254;
  --accent-light: #EBF1F5;
  --highlight-bg: #FFF089;
  --highlight-text: #1F2328;
  --highlight-border: #E8D44F;
  --badge-green-bg: #DCFCE7;
  --badge-green-text: #166534;
}

/* 3. DARK THEME (Night) */
body.theme-dark {
  --bg-app: #141517;
  --bg-page: #1C1E21;
  --bg-card: #23272E;
  --bg-subtle: #2D333B;
  --text-main: #D8DEE9;
  --text-muted: #9BA3AF;
  --text-faint: #636D7D;
  --border-color: #373E47;
  --border-subtle: #2B3037;
  --accent: #E5A93C;
  --accent-hover: #F2B954;
  --accent-light: #342B1B;
  --highlight-bg: #5E4B1E;
  --highlight-text: #FFE082;
  --highlight-border: #806526;
  --badge-green-bg: #1B3D2B;
  --badge-green-text: #7EE787;
}

/* Typeface classes */
body.font-serif {
  font-family: var(--font-serif);
}
body.font-sans {
  font-family: var(--font-sans);
}

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

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

body {
  background-color: var(--bg-app);
  color: var(--text-main);
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  overflow-x: hidden;
  transition: background-color var(--transition-normal), color var(--transition-normal);
}

/* ==========================================================================
   KILLER FEATURE: STEALTH MODE (TEACHER VIEW MODE)
   ========================================================================== */
body.stealth-active .non-stealth {
  display: none !important;
}

body.stealth-active {
  --header-height: 50px;
}

body.stealth-active .app-header {
  border-bottom: 1px solid var(--border-subtle);
  background: var(--bg-page);
}

body.stealth-active .book-author {
  font-size: 0.85rem;
  letter-spacing: 0.05em;
  text-transform: uppercase;
}

body.stealth-active .reader-page {
  padding-bottom: 40px;
}

/* ==========================================================================
   HEADER
   ========================================================================== */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  height: var(--header-height);
  background-color: var(--bg-app);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 16px;
  backdrop-filter: blur(8px);
}

.header-left, .header-right {
  display: flex;
  align-items: center;
  gap: 10px;
}

.book-identity {
  display: flex;
  flex-direction: column;
}

.book-author {
  font-size: 0.72rem;
  font-family: var(--font-sans);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.06em;
  line-height: 1;
}

.book-title {
  font-size: 1.05rem;
  font-weight: 700;
  line-height: 1.2;
}

.icon-btn {
  background: none;
  border: none;
  color: var(--text-main);
  padding: 8px;
  border-radius: var(--radius-sm);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  transition: background-color var(--transition-fast);
}

.icon-btn:hover {
  background-color: var(--bg-subtle);
}

/* Sync Indicator */
.sync-indicator {
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: var(--text-muted);
  padding: 4px 8px;
  border-radius: 12px;
  background: var(--bg-card);
  border: 1px solid var(--border-subtle);
}

.sync-dot {
  width: 7px;
  height: 7px;
  border-radius: 50%;
  background-color: #22C55E;
}

.sync-indicator.offline .sync-dot {
  background-color: #EAB308;
}

/* Stealth Toggle Button */
.stealth-toggle-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 12px;
  border-radius: 20px;
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.stealth-toggle-btn:hover {
  border-color: var(--accent);
}

body.stealth-active .stealth-toggle-btn {
  background-color: var(--bg-subtle);
  border-color: var(--border-color);
  opacity: 0.6;
}

/* ==========================================================================
   APPEARANCE SETTINGS PANEL
   ========================================================================== */
.appearance-panel {
  position: absolute;
  top: calc(var(--header-height) + 4px);
  right: 16px;
  z-index: 110;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-lg);
  width: 290px;
  padding: 16px;
  font-family: var(--font-sans);
}

.appearance-header {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 12px;
  padding-bottom: 8px;
  border-bottom: 1px solid var(--border-color);
}

.panel-title {
  font-size: 0.85rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  color: var(--text-muted);
}

.close-btn {
  background: none;
  border: none;
  font-size: 1.3rem;
  line-height: 1;
  color: var(--text-muted);
  cursor: pointer;
}

.setting-group {
  margin-bottom: 14px;
}

.setting-label {
  display: block;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.theme-buttons, .font-buttons, .font-size-controls {
  display: flex;
  gap: 6px;
}

.theme-btn, .font-btn, .size-btn, .width-btn {
  flex: 1;
  padding: 7px 4px;
  border: 1px solid var(--border-color);
  background-color: var(--bg-app);
  color: var(--text-main);
  border-radius: var(--radius-sm);
  font-size: 0.8rem;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.theme-btn.active, .font-btn.active, .width-btn.active {
  border-color: var(--accent);
  background-color: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

.btn-sepia { background-color: #F4ECD8; color: #2C2621; }
.btn-light { background-color: #FFFFFF; color: #1F2328; }
.btn-dark { background-color: #1C1E21; color: #D8DEE9; }

/* ==========================================================================
   APP LAYOUT (Mobile & Desktop)
   ========================================================================== */
.app-layout {
  display: flex;
  flex: 1;
  position: relative;
}

/* Sidebar (TOC) */
.app-sidebar {
  position: fixed;
  top: 0;
  left: 0;
  bottom: 0;
  width: 290px;
  background-color: var(--bg-card);
  border-right: 1px solid var(--border-color);
  z-index: 150;
  display: flex;
  flex-direction: column;
  transform: translateX(-100%);
  transition: transform var(--transition-normal);
  overflow-y: auto;
}

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

.sidebar-header {
  height: var(--header-height);
  padding: 0 16px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  border-bottom: 1px solid var(--border-color);
}

.sidebar-title {
  font-weight: 700;
  font-size: 1.05rem;
}

/* Desktop Nav in Sidebar */
.desktop-nav {
  display: flex;
  flex-direction: column;
  gap: 2px;
  padding: 12px 8px;
  border-bottom: 1px solid var(--border-color);
}

.nav-item {
  display: flex;
  align-items: center;
  gap: 12px;
  padding: 10px 12px;
  border-radius: var(--radius-sm);
  border: none;
  background: none;
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 500;
  text-align: left;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.nav-item:hover {
  background-color: var(--bg-subtle);
}

.nav-item.active {
  background-color: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

.toc-heading {
  padding: 14px 16px 6px;
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--text-muted);
}

.toc-list {
  display: flex;
  flex-direction: column;
  padding: 4px 8px 24px;
}

.toc-item {
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  border: none;
  background: none;
  color: var(--text-main);
  text-align: left;
  font-family: var(--font-sans);
  font-size: 0.88rem;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

.toc-item:hover {
  background-color: var(--bg-subtle);
}

.toc-item.active {
  background-color: var(--accent-light);
  color: var(--accent);
  font-weight: 600;
}

/* Overlay Backdrop */
.overlay-backdrop {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.4);
  backdrop-filter: blur(2px);
  z-index: 140;
  opacity: 0;
  pointer-events: none;
  transition: opacity var(--transition-fast);
}

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

/* Main Content */
.main-content {
  flex: 1;
  width: 100%;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding-bottom: calc(var(--bottom-nav-height) + 24px);
}

body.stealth-active .main-content {
  padding-bottom: 24px;
}

/* ==========================================================================
   TAB VIEWS
   ========================================================================== */
.tab-view {
  display: none;
  width: 100%;
}

.tab-view.active {
  display: flex;
  justify-content: center;
}

#tabReader.active {
  display: grid;
  grid-template-columns: 1fr;
  width: 100%;
  max-width: 1300px;
  margin: 0 auto;
}

/* ==========================================================================
   TAB 1: READER PAGE
   ========================================================================== */
.reader-page {
  width: 100%;
  max-width: 780px;
  margin: 0 auto;
  padding: 20px 20px 60px;
  background-color: var(--bg-page);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  transition: background-color var(--transition-normal);
}

/* Toolbar */
.reader-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
}

.version-segmented-control {
  display: flex;
  background-color: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: 20px;
  padding: 3px;
  gap: 2px;
}

.version-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 5px 12px;
  border: none;
  background: none;
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  border-radius: 16px;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.version-btn .v-tag {
  font-size: 0.68rem;
  padding: 2px 5px;
  border-radius: 4px;
  background: var(--border-color);
  font-weight: 700;
}

.version-btn.active {
  background-color: var(--bg-page);
  box-shadow: var(--shadow-sm);
  color: var(--accent);
  font-weight: 600;
}

.action-btn-highlight {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 6px 14px;
  border-radius: 20px;
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.8rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.action-btn-highlight:hover {
  background-color: var(--highlight-bg);
  color: var(--highlight-text);
  border-color: var(--highlight-border);
}

/* Chapter Header */
.chapter-header {
  text-align: center;
  margin-bottom: 28px;
}

.chapter-meta {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  margin-bottom: 8px;
  font-family: var(--font-sans);
}

.chapter-number-badge {
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.08em;
  text-transform: uppercase;
  color: var(--accent);
}

.chapter-version-label {
  font-size: 0.72rem;
  color: var(--text-muted);
}

.chapter-title {
  font-size: 1.6rem;
  font-weight: 700;
  line-height: 1.3;
}

/* Russian Summary Card */
.chapter-summary-card {
  margin-bottom: 28px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--bg-card);
  overflow: hidden;
}

.summary-toggle-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 10px 14px;
  background: none;
  border: none;
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.82rem;
  font-weight: 600;
  cursor: pointer;
  text-align: left;
}

.summary-chevron {
  font-size: 0.75rem;
  transition: transform var(--transition-fast);
}

.summary-toggle-btn[aria-expanded="true"] .summary-chevron {
  transform: rotate(180deg);
}

.summary-body {
  display: none;
  padding: 12px 14px 14px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-main);
  border-top: 1px dashed var(--border-color);
  background-color: var(--bg-subtle);
}

.summary-body.expanded {
  display: block;
}

/* Book Passage Container */
.book-text-container {
  max-width: var(--max-content-width);
  margin: 0 auto;
}

.book-paragraphs {
  font-size: 1.125rem;
  line-height: var(--line-height-reader);
  letter-spacing: 0.005em;
  word-wrap: break-word;
}

.book-p {
  margin-bottom: 1.5em;
  text-indent: 1.5em;
}

.book-p:first-of-type {
  text-indent: 0;
}

/* Clickable Interactive Words */
.reader-word {
  cursor: pointer;
  border-radius: 3px;
  padding: 1px 2px;
  margin: 0 -2px;
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.reader-word:hover {
  background-color: rgba(166, 93, 55, 0.12);
}

/* Word Highlights (in both regular & stealth mode) */
.reader-word.highlighted {
  background-color: var(--highlight-bg) !important;
  color: var(--highlight-text) !important;
  border-bottom: 1.5px solid var(--highlight-border);
  font-weight: 500;
}

.reader-word.active-inspect {
  outline: 2px solid var(--accent);
}

/* Chapter Footer */
.chapter-nav-footer {
  margin-top: 48px;
  padding-top: 24px;
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.chapter-nav-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 16px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

.chapter-nav-btn:hover:not(:disabled) {
  border-color: var(--accent);
  color: var(--accent);
}

.chapter-nav-btn:disabled {
  opacity: 0.4;
  cursor: not-allowed;
}

.chapter-page-indicator {
  font-family: var(--font-sans);
  font-size: 0.85rem;
  color: var(--text-muted);
}

/* Desktop Word Inspector (Right Column) */
.desktop-word-inspector {
  display: none;
}

@media (min-width: 1100px) {
  #tabReader.active {
    grid-template-columns: 1fr 340px;
    gap: 32px;
    padding: 0 24px;
  }
  
  .desktop-word-inspector {
    display: block;
    position: sticky;
    top: calc(var(--header-height) + 24px);
    height: fit-content;
    background-color: var(--bg-card);
    border: 1px solid var(--border-color);
    border-radius: var(--radius-md);
    padding: 20px;
    box-shadow: var(--shadow-sm);
  }
}

.inspector-empty {
  text-align: center;
  padding: 30px 10px;
  color: var(--text-muted);
  font-family: var(--font-sans);
}

.empty-icon {
  font-size: 2rem;
  margin-bottom: 12px;
}

.empty-title {
  font-weight: 600;
  font-size: 1rem;
  color: var(--text-main);
  margin-bottom: 8px;
}

.empty-hint {
  font-size: 0.85rem;
  line-height: 1.5;
}

.inspector-card .card-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 16px;
  padding-bottom: 14px;
  border-bottom: 1px solid var(--border-color);
}

.word-main {
  display: flex;
  align-items: center;
  gap: 8px;
}

.word-name, .sheet-word-name {
  font-size: 1.4rem;
  font-weight: 700;
}

.audio-btn {
  background: var(--bg-subtle);
  border: 1px solid var(--border-color);
  border-radius: 50%;
  width: 32px;
  height: 32px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--accent);
  transition: all var(--transition-fast);
}

.audio-btn:hover {
  background: var(--accent);
  color: #FFFFFF;
}

.word-badges {
  display: flex;
  flex-direction: column;
  align-items: flex-end;
  gap: 4px;
}

.ipa-badge {
  font-family: var(--font-serif);
  font-size: 0.85rem;
  color: var(--accent);
}

.type-badge {
  font-family: var(--font-sans);
  font-size: 0.68rem;
  padding: 2px 6px;
  border-radius: 4px;
  background: var(--bg-subtle);
  color: var(--text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  font-weight: 600;
}

.card-section {
  margin-bottom: 14px;
  font-family: var(--font-sans);
}

.section-label {
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--text-muted);
  margin-bottom: 4px;
}

.translation-text {
  font-size: 1.05rem;
  font-weight: 600;
  color: var(--text-main);
}

.definition-text {
  font-size: 0.9rem;
  line-height: 1.45;
  color: var(--text-main);
}

.synonyms-tags {
  display: flex;
  flex-wrap: wrap;
  gap: 6px;
}

.syn-tag {
  font-size: 0.78rem;
  padding: 2px 7px;
  border-radius: 12px;
  background: var(--bg-subtle);
  color: var(--text-muted);
}

.context-quote {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--text-muted);
  border-left: 2px solid var(--accent);
  padding-left: 10px;
  margin-top: 4px;
}

.card-actions, .sheet-actions {
  display: flex;
  gap: 8px;
  margin-top: 18px;
}

.btn-primary {
  flex: 1;
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  background-color: var(--accent);
  color: #FFFFFF;
  border: none;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 600;
  cursor: pointer;
  transition: background-color var(--transition-fast);
}

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

.btn-secondary {
  padding: 9px 12px;
  border-radius: var(--radius-sm);
  background: none;
  border: 1px solid var(--border-color);
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  cursor: pointer;
}

.btn-secondary:hover {
  background-color: var(--bg-subtle);
  color: var(--text-main);
}

/* ==========================================================================
   MOBILE BOTTOM SHEET
   ========================================================================== */
.bottom-sheet {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  background-color: var(--bg-card);
  border-top-left-radius: var(--radius-lg);
  border-top-right-radius: var(--radius-lg);
  border-top: 1px solid var(--border-color);
  box-shadow: var(--shadow-lg);
  z-index: 200;
  padding: 12px 20px 24px;
  transform: translateY(110%);
  transition: transform var(--transition-normal);
  max-height: 80vh;
  overflow-y: auto;
}

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

.sheet-drag-handle {
  width: 40px;
  height: 4px;
  border-radius: 2px;
  background-color: var(--border-color);
  margin: 0 auto 14px;
}

.sheet-head {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 14px;
}

/* ==========================================================================
   STUDIO VIEWS (GLOSSARY, BOOK REPORT, TRAINER)
   ========================================================================== */
.studio-container {
  width: 100%;
  max-width: 960px;
  margin: 0 auto;
  padding: 24px 20px 80px;
}

.studio-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: flex-start;
  gap: 16px;
  margin-bottom: 24px;
  padding-bottom: 16px;
  border-bottom: 1px solid var(--border-color);
}

.studio-title {
  font-size: 1.5rem;
  font-weight: 700;
  margin-bottom: 4px;
}

.studio-subtitle {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  color: var(--text-muted);
  max-width: 600px;
}

.studio-actions {
  display: flex;
  gap: 8px;
}

.action-btn {
  display: flex;
  align-items: center;
  gap: 6px;
  padding: 8px 14px;
  border-radius: var(--radius-sm);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.85rem;
  font-weight: 500;
  cursor: pointer;
  transition: all var(--transition-fast);
}

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

/* ==========================================================================
   TAB 2: GLOSSARY TABLE
   ========================================================================== */
.filter-bar {
  display: flex;
  flex-wrap: wrap;
  gap: 12px;
  margin-bottom: 18px;
  align-items: center;
  justify-content: space-between;
}

.search-box {
  display: flex;
  align-items: center;
  gap: 8px;
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  padding: 8px 12px;
  flex: 1;
  min-width: 240px;
}

.search-box input {
  border: none;
  background: none;
  outline: none;
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.88rem;
  width: 100%;
}

.type-filter-group {
  display: flex;
  gap: 6px;
  overflow-x: auto;
  padding-bottom: 4px;
}

.type-filter-btn {
  padding: 6px 12px;
  border-radius: 16px;
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  color: var(--text-main);
  font-family: var(--font-sans);
  font-size: 0.78rem;
  font-weight: 500;
  cursor: pointer;
  white-space: nowrap;
}

.type-filter-btn.active {
  background-color: var(--accent-light);
  border-color: var(--accent);
  color: var(--accent);
  font-weight: 600;
}

.table-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  box-shadow: var(--shadow-sm);
  overflow: hidden;
}

.table-responsive {
  overflow-x: auto;
}

.glossary-table {
  width: 100%;
  border-collapse: collapse;
  text-align: left;
  font-family: var(--font-sans);
  font-size: 0.88rem;
}

.glossary-table th {
  background-color: var(--bg-subtle);
  color: var(--text-muted);
  font-size: 0.75rem;
  font-weight: 700;
  letter-spacing: 0.05em;
  text-transform: uppercase;
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-color);
}

.glossary-table td {
  padding: 12px 14px;
  border-bottom: 1px solid var(--border-subtle);
  vertical-align: top;
}

.glossary-table tbody tr:hover {
  background-color: var(--bg-subtle);
}

.table-word-cell {
  display: flex;
  align-items: center;
  gap: 8px;
}

.table-word {
  font-weight: 700;
  color: var(--text-main);
}

.table-ipa {
  font-family: var(--font-serif);
  color: var(--accent);
  white-space: nowrap;
}

.table-context {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.82rem;
  color: var(--text-muted);
  cursor: pointer;
}

.table-context:hover {
  color: var(--accent);
  text-decoration: underline;
}

/* ==========================================================================
   TAB 3: BOOK REPORT STUDIO
   ========================================================================== */
.report-block-card {
  background-color: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  margin-bottom: 24px;
  box-shadow: var(--shadow-sm);
}

.block-card-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
  padding-bottom: 12px;
  border-bottom: 1px solid var(--border-color);
}

.block-label {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  font-weight: 700;
  letter-spacing: 0.06em;
  text-transform: uppercase;
  color: var(--accent);
}

.block-heading {
  font-size: 1.15rem;
  font-weight: 700;
}

.block-badges {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-wrap: wrap;
}

.sentence-counter-badge {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  padding: 4px 10px;
  border-radius: 12px;
  background-color: var(--bg-subtle);
  color: var(--text-muted);
}

.sentence-counter-badge.badge-valid {
  background-color: var(--badge-green-bg);
  color: var(--badge-green-text);
}

.btn-audio-pill {
  display: flex;
  align-items: center;
  gap: 4px;
  padding: 4px 10px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  background: var(--bg-app);
  color: var(--accent);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  font-weight: 600;
  cursor: pointer;
}

.btn-trans-toggle {
  padding: 4px 10px;
  border-radius: 12px;
  border: 1px solid var(--border-color);
  background: var(--bg-app);
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.75rem;
  cursor: pointer;
}

.report-textarea {
  width: 100%;
  padding: 12px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--bg-page);
  color: var(--text-main);
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.7;
  resize: vertical;
  outline: none;
  transition: border-color var(--transition-fast);
}

.report-textarea:focus {
  border-color: var(--accent);
}

.report-ru-box {
  margin-top: 10px;
  padding: 12px 14px;
  border-radius: var(--radius-sm);
  background-color: var(--bg-subtle);
  border-left: 3px solid var(--accent);
  font-family: var(--font-sans);
  font-size: 0.9rem;
  line-height: 1.6;
  color: var(--text-muted);
}

/* Characters Grid */
.characters-grid {
  display: grid;
  grid-template-columns: 1fr;
  gap: 16px;
}

@media (min-width: 768px) {
  .characters-grid {
    grid-template-columns: 1fr 1fr;
  }
}

.char-card {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--bg-page);
  padding: 16px;
}

.char-card-header {
  display: flex;
  justify-content: space-between;
  align-items: flex-start;
  margin-bottom: 10px;
}

.char-name {
  font-size: 1.05rem;
  font-weight: 700;
}

.char-role {
  font-family: var(--font-sans);
  font-size: 0.75rem;
  color: var(--text-muted);
}

.sub-block {
  margin-top: 16px;
  padding-top: 16px;
  border-top: 1px solid var(--border-color);
}

.sub-block-header {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 8px;
  margin-bottom: 10px;
}

.sub-title {
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
}

/* ==========================================================================
   TAB 4: FLASHCARDS TRAINER & 15 Q&A
   ========================================================================== */
.trainer-section {
  margin-bottom: 48px;
}

.flashcard-scene {
  perspective: 1000px;
  width: 100%;
  max-width: 500px;
  height: 280px;
  margin: 0 auto 20px;
}

.flashcard {
  width: 100%;
  height: 100%;
  position: relative;
  transform-style: preserve-3d;
  transition: transform 0.5s cubic-bezier(0.175, 0.885, 0.32, 1.275);
  cursor: pointer;
}

.flashcard.flipped {
  transform: rotateY(180deg);
}

.flashcard-face {
  position: absolute;
  inset: 0;
  backface-visibility: hidden;
  border-radius: var(--radius-md);
  border: 1px solid var(--border-color);
  background-color: var(--bg-card);
  box-shadow: var(--shadow-md);
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 24px;
  text-align: center;
}

.flashcard-front {
  gap: 10px;
}

.fc-tip {
  font-family: var(--font-sans);
  font-size: 0.72rem;
  color: var(--text-faint);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.fc-word {
  font-size: 2rem;
  font-weight: 700;
}

.fc-ipa {
  font-family: var(--font-serif);
  font-size: 1.1rem;
  color: var(--accent);
}

.flashcard-back {
  transform: rotateY(180deg);
  background-color: var(--bg-page);
  gap: 12px;
}

.fc-trans {
  font-size: 1.3rem;
  font-weight: 700;
  color: var(--accent);
}

.fc-def {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  line-height: 1.4;
  color: var(--text-main);
}

.fc-synonyms {
  font-family: var(--font-sans);
  font-size: 0.82rem;
  color: var(--text-muted);
}

.fc-context {
  font-family: var(--font-serif);
  font-style: italic;
  font-size: 0.85rem;
  color: var(--text-muted);
}

.flashcard-controls {
  display: flex;
  justify-content: center;
  gap: 16px;
}

.fc-action-btn {
  display: flex;
  align-items: center;
  gap: 8px;
  padding: 10px 20px;
  border-radius: 24px;
  font-family: var(--font-sans);
  font-size: 0.9rem;
  font-weight: 600;
  cursor: pointer;
  border: none;
  transition: all var(--transition-fast);
}

.btn-repeat {
  background-color: var(--bg-subtle);
  color: var(--text-main);
  border: 1px solid var(--border-color);
}

.btn-know {
  background-color: var(--accent);
  color: #FFFFFF;
}

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

/* 15 Teacher Q&A Accordion */
.qa-accordion {
  display: flex;
  flex-direction: column;
  gap: 12px;
}

.qa-card {
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  background-color: var(--bg-card);
  overflow: hidden;
}

.qa-question-btn {
  width: 100%;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 16px;
  background: none;
  border: none;
  color: var(--text-main);
  text-align: left;
  cursor: pointer;
  gap: 12px;
}

.qa-question-text {
  font-family: var(--font-sans);
  font-size: 0.95rem;
  font-weight: 600;
}

.qa-question-ru {
  display: block;
  font-size: 0.82rem;
  font-weight: 400;
  color: var(--text-muted);
  margin-top: 2px;
}

.qa-answer-body {
  display: none;
  padding: 14px 16px;
  border-top: 1px solid var(--border-color);
  background-color: var(--bg-page);
}

.qa-answer-body.expanded {
  display: block;
}

.qa-answer-en {
  font-family: var(--font-serif);
  font-size: 1rem;
  line-height: 1.6;
  margin-bottom: 8px;
}

.qa-answer-ru {
  font-family: var(--font-sans);
  font-size: 0.88rem;
  line-height: 1.5;
  color: var(--text-muted);
  border-top: 1px dashed var(--border-color);
  padding-top: 8px;
}

/* ==========================================================================
   MOBILE BOTTOM NAVIGATION BAR
   ========================================================================== */
.mobile-bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  height: var(--bottom-nav-height);
  background-color: var(--bg-card);
  border-top: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-around;
  z-index: 100;
  backdrop-filter: blur(8px);
}

@media (min-width: 900px) {
  .mobile-bottom-nav {
    display: none;
  }
}

.bottom-nav-item {
  flex: 1;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 3px;
  background: none;
  border: none;
  color: var(--text-muted);
  font-family: var(--font-sans);
  font-size: 0.68rem;
  font-weight: 500;
  cursor: pointer;
  padding: 8px 0;
  transition: color var(--transition-fast);
}

.bottom-nav-item.active {
  color: var(--accent);
  font-weight: 700;
}

/* Toast Notification */
.toast-container {
  position: fixed;
  bottom: calc(var(--bottom-nav-height) + 16px);
  left: 50%;
  transform: translateX(-50%);
  z-index: 300;
  display: flex;
  flex-direction: column;
  gap: 8px;
  pointer-events: none;
}

.toast {
  background-color: var(--bg-card);
  color: var(--text-main);
  border: 1px solid var(--border-color);
  padding: 8px 16px;
  border-radius: 20px;
  font-family: var(--font-sans);
  font-size: 0.85rem;
  box-shadow: var(--shadow-md);
  animation: toastFade 2.5s forwards;
}

@keyframes toastFade {
  0% { opacity: 0; transform: translateY(10px); }
  15% { opacity: 1; transform: translateY(0); }
  85% { opacity: 1; transform: translateY(0); }
  100% { opacity: 0; transform: translateY(-10px); }
}

/* Print Styles */
@media print {
  .app-header, .app-sidebar, .mobile-bottom-nav, .filter-bar, .studio-actions, .chapter-nav-footer, .reader-toolbar {
    display: none !important;
  }
  body, .main-content, .studio-container {
    background: #FFFFFF !important;
    color: #000000 !important;
    padding: 0 !important;
    margin: 0 !important;
  }
  .table-card {
    border: none !important;
    box-shadow: none !important;
  }
  .glossary-table th, .glossary-table td {
    border: 1px solid #CCCCCC !important;
    color: #000000 !important;
  }
}