/* ============================================
   Material 3 Education - Gaokao English Exam
   ============================================ */

/* CSS Variables based on design.md */
:root {
  /* Colors */
  --primary: #1A73E8;
  --primary-hover: #1557B0;
  --primary-container: #D2E3FC;
  --primary-on-container: #001D35;
  --secondary: #34A853;
  --secondary-container: #CEEAD6;
  --on-secondary-container: #002111;
  --tertiary-container: #E8F0FE;
  --on-tertiary-container: #001A41;
  --warning: #FBBC04;
  --warning-container: #FEF7E0;
  --on-warning-container: #5F4900;
  --error: #EA4335;
  --error-container: #FCE8E6;
  --on-error-container: #410E0B;
  --background: #F8F9FA;
  --surface: #FFFFFF;
  --text-primary: #202124;
  --text-secondary: #5F6368;
  --outline: #DADCE0;
  --outline-variant: #E8EAED;
  --accent-blue: #4285F4;

  /* Typography */
  --font-heading: 'Times New Roman', 'Noto Sans SC', Georgia, serif;
  --font-body: 'Times New Roman', 'Noto Sans SC', Georgia, serif;
  --font-reading: 'Times New Roman', 'Noto Sans SC', Georgia, serif;

  /* Spacing */
  --space-xs: 8px;
  --space-sm: 16px;
  --space-md: 24px;
  --space-lg: 32px;
  --space-xl: 48px;
  --space-xxl: 64px;
  --section-gap: 72px;

  /* Layout */
  --max-width: 1400px;
  --content-max-width: 1600px;
  --content-width: 1200px;
  --navbar-height: 72px;
  --card-gap: 24px;

  /* Border Radius */
  --radius-xs: 6px;
  --radius-sm: 12px;
  --radius-md: 18px;
  --radius-lg: 24px;
  --radius-xl: 32px;
  --radius-pill: 9999px;

  /* Shadows */
  --elevation-1: 0 1px 3px rgba(60, 64, 67, 0.15), 0 1px 2px rgba(60, 64, 67, 0.10);
  --elevation-2: 0 4px 12px rgba(60, 64, 67, 0.18);
  --elevation-3: 0 8px 24px rgba(60, 64, 67, 0.24);
  --shadow-1: 0 1px 3px rgba(60,64,67,0.15);
  --shadow-2: 0 4px 12px rgba(60,64,67,0.18);
  --shadow-3: 0 8px 24px rgba(60,64,67,0.24);
}

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

html {
  scroll-behavior: smooth;
  font-size: 24px;
}

body {
  font-family: var(--font-body);
  font-size: 24px;
  background-color: var(--background);
  color: var(--text-primary);
  line-height: 1.8;
  min-height: 100vh;
}

/* Typography */
h1, h2, h3, h4, h5, h6 {
  font-family: var(--font-heading);
  font-weight: 700;
  line-height: 1.3;
  color: var(--text-primary);
}

h1 { font-size: 48px; }
h2 { font-size: 36px; }
h3 { font-size: 28px; font-weight: 600; }

p {
  font-size: 24px;
  line-height: 1.8;
  color: var(--text-primary);
}

/* Navbar */
.navbar {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--navbar-height);
  background: var(--surface);
  box-shadow: var(--shadow-1);
  z-index: 1000;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-lg);
}

.navbar-brand {
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 700;
  color: var(--primary);
  text-decoration: none;
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.navbar-brand .icon {
  width: 40px;
  height: 40px;
  background: var(--primary);
  color: white;
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
}

.navbar-nav {
  display: flex;
  gap: var(--space-xs);
  list-style: none;
}

.nav-link {
  font-family: var(--font-heading);
  font-size: 18px;
  font-weight: 600;
  color: var(--text-secondary);
  text-decoration: none;
  padding: var(--space-xs) var(--space-md);
  border-radius: var(--radius-pill);
  transition: all 0.2s ease;
}

.nav-link:hover,
.nav-link.active {
  color: var(--primary);
  background: #E8F0FE;
}

/* Main Layout */
.main-content {
  margin-top: var(--navbar-height);
  min-height: calc(100vh - var(--navbar-height));
}

.container {
  max-width: var(--content-width);
  margin: 0 auto;
  padding: var(--space-xl) var(--space-lg);
}

/* Hero Section */
.hero {
  background: linear-gradient(135deg, var(--primary) 0%, var(--accent-blue) 100%);
  color: white;
  padding: var(--space-xxl) var(--space-lg);
  text-align: center;
  margin-bottom: var(--space-xl);
}

.hero h1 {
  font-size: 56px;
  font-weight: 700;
  color: white;
  margin-bottom: var(--space-md);
}

.hero p {
  font-size: 24px;
  color: rgba(255,255,255,0.9);
  max-width: 700px;
  margin: 0 auto;
}

.hero-meta {
  display: flex;
  justify-content: center;
  gap: var(--space-xl);
  margin-top: var(--space-lg);
  font-size: 18px;
  color: rgba(255,255,255,0.85);
}

/* Section Headers */
.section-header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--outline);
}

.section-number {
  width: 48px;
  height: 48px;
  background: var(--primary);
  color: white;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 22px;
  font-weight: 700;
  flex-shrink: 0;
}

.section-title {
  font-size: 32px;
  font-weight: 700;
  color: var(--text-primary);
}

/* Cards */
.card {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  box-shadow: var(--shadow-1);
  margin-bottom: var(--space-md);
  transition: box-shadow 0.2s ease;
}

.card:hover {
  box-shadow: var(--shadow-2);
}

.card-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 1px solid var(--outline);
}

.card-badge {
  padding: 4px 12px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.badge-listening { background: #E8F0FE; color: var(--primary); }
.badge-reading { background: #E6F4EA; color: var(--secondary); }
.badge-cloze { background: #FEF3E8; color: #E65100; }
.badge-writing { background: #FCE8E8; color: var(--error); }

/* Question Items */
.question-item {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin-bottom: var(--space-md);
  box-shadow: var(--shadow-1);
  border-left: 4px solid var(--primary);
}

.question-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  background: var(--primary);
  color: white;
  border-radius: var(--radius-sm);
  font-size: 24px;
  font-weight: 700;
  margin-right: var(--space-sm);
  flex-shrink: 0;
}

.question-text {
  font-size: 24px;
  line-height: 1.6;
  margin-bottom: var(--space-md);
  color: var(--text-primary);
}

/* Options */
.options-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-sm);
}

.option-item {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-md);
  background: var(--background);
  border-radius: var(--radius-sm);
  cursor: pointer;
  transition: all 0.2s ease;
  border: 2px solid transparent;
}

.option-item:hover {
  background: #E8F0FE;
  border-color: var(--primary);
}

.option-item.correct {
  background: #E6F4EA;
  border-color: var(--secondary);
}

.option-item.wrong {
  background: #FCE8E8;
  border-color: var(--error);
}

.option-letter {
  width: 40px;
  height: 40px;
  background: var(--surface);
  border: 2px solid var(--outline);
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  font-weight: 700;
  color: var(--text-secondary);
  flex-shrink: 0;
}

.option-item.correct .option-letter {
  background: var(--secondary);
  border-color: var(--secondary);
  color: white;
}

.option-item.wrong .option-letter {
  background: var(--error);
  border-color: var(--error);
  color: white;
}

.option-text {
  font-size: 24px;
  color: var(--text-primary);
}

/* Answer Toggle Button */
.answer-toggle {
  display: inline-flex;
  align-items: center;
  gap: var(--space-xs);
  padding: var(--space-xs) var(--space-md);
  background: var(--primary);
  color: white;
  border: none;
  border-radius: var(--radius-pill);
  font-size: 16px;
  font-weight: 600;
  cursor: pointer;
  margin-top: var(--space-md);
  transition: background 0.2s ease;
}

.answer-toggle:hover {
  background: var(--primary-hover);
}

.answer-content {
  display: none;
  margin-top: var(--space-md);
  padding: var(--space-md);
  background: #F8F9FA;
  border-radius: var(--radius-sm);
  border-left: 4px solid var(--secondary);
}

.answer-content.show {
  display: block;
}

.answer-label {
  font-size: 16px;
  font-weight: 600;
  color: var(--secondary);
  margin-bottom: var(--space-xs);
  text-transform: uppercase;
  letter-spacing: 0.5px;
}

.answer-text {
  font-size: 20px;
  color: var(--text-primary);
  line-height: 1.6;
}

/* Dialogue/Passage Box */
.passage-box {
  background: #F8F9FA;
  border-radius: var(--radius-md);
  padding: var(--space-md);
  margin-bottom: var(--space-lg);
  border: 1px solid var(--outline);
}

.passage-title {
  font-size: 22px;
  font-weight: 600;
  color: var(--primary);
  margin-bottom: var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-sm);
}

.passage-text {
  font-size: 20px;
  line-height: 2;
  color: var(--text-primary);
}

/* Reading Passage */
.reading-passage {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
  box-shadow: var(--shadow-1);
}

.reading-passage h3 {
  font-size: 28px;
  color: var(--primary);
  margin-bottom: var(--space-md);
}

.reading-passage p {
  font-size: 22px;
  line-height: 2;
  margin-bottom: var(--space-md);
  text-align: justify;
}

/* Cloze (Fill in blanks) */
.cloze-text {
  font-size: 22px;
  line-height: 2.2;
}

.blank {
  display: inline-block;
  min-width: 80px;
  border-bottom: 2px solid var(--primary);
  margin: 0 4px;
  text-align: center;
  font-weight: 600;
  color: var(--primary);
}

.blank-answer {
  color: var(--secondary);
  font-weight: 700;
}

/* Writing Section */
.writing-prompt {
  background: #FFF8E1;
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
  border-left: 4px solid var(--warning);
}

.writing-prompt h3 {
  color: #E65100;
  margin-bottom: var(--space-md);
}

.writing-prompt p {
  font-size: 22px;
  line-height: 2;
}

.writing-sample {
  background: var(--surface);
  border-radius: var(--radius-md);
  padding: var(--space-lg);
  box-shadow: var(--shadow-1);
}

.writing-sample h4 {
  font-size: 24px;
  color: var(--primary);
  margin-bottom: var(--space-md);
  padding-bottom: var(--space-sm);
  border-bottom: 2px solid var(--outline);
}

.writing-sample p {
  font-size: 20px;
  line-height: 2;
  margin-bottom: var(--space-md);
}

/* Grid Layout for Questions */
.questions-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(500px, 1fr));
  gap: var(--space-md);
}

/* Listening Section Specific */
.listening-group {
  background: var(--surface);
  border-radius: var(--radius-lg);
  padding: var(--space-lg);
  margin-bottom: var(--space-xl);
  box-shadow: var(--shadow-1);
}

.listening-group-header {
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
  padding-bottom: var(--space-md);
  border-bottom: 2px solid var(--outline);
}

.listening-group-icon {
  width: 48px;
  height: 48px;
  background: #E8F0FE;
  color: var(--primary);
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
}

.listening-group-title {
  font-size: 24px;
  font-weight: 600;
  color: var(--text-primary);
}

/* Audio Player Placeholder */
.audio-player {
  background: #E8F0FE;
  border-radius: var(--radius-pill);
  padding: var(--space-sm) var(--space-md);
  display: flex;
  align-items: center;
  gap: var(--space-md);
  margin-bottom: var(--space-lg);
}

.audio-player .play-btn {
  width: 48px;
  height: 48px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  cursor: pointer;
  transition: background 0.2s ease;
}

.audio-player .play-btn:hover {
  background: var(--primary-hover);
}

.audio-player .audio-label {
  font-size: 18px;
  font-weight: 600;
  color: var(--primary);
}

/* Seven Selected Five (七选五) */
.seven-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 16px;
}

/* ============================================================
   Cloze Grid - Left Article, Right Options
   ============================================================ */
.options-grid {
  display: flex;
  flex-direction: column;
  gap: var(--space-md);
}

.option-row {
  display: flex;
  gap: var(--space-md);
}

.option-row > .option-group {
  flex: 1;
}

.option-group {
  background: var(--background);
  border-radius: var(--radius-md);
  padding: var(--space-md);
}

.option-group-title {
  font-size: 18px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: var(--space-sm);
  padding-bottom: var(--space-xs);
  border-bottom: 2px solid var(--primary);
}

/* Gap Blank (for grammar and seven-select) */
.gap-blank {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 64px;
  padding: 4px 12px;
  background: var(--tertiary-container);
  color: var(--primary);
  border-bottom: 2px solid var(--primary);
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 700;
  vertical-align: middle;
}

/* Answer Grid */
.answer-grid {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 16px;
}

.answer-item {
  display: flex;
  align-items: baseline;
  gap: 16px;
  padding: 12px 16px;
  background: var(--surface);
  border: 1px solid var(--outline);
  border-radius: var(--radius-sm);
}

.answer-item .gap-num {
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 700;
  color: var(--primary);
  min-width: 40px;
}

.answer-item .gap-key {
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 700;
  color: var(--secondary);
  min-width: 80px;
}

.answer-item .gap-exp {
  font-size: 24px;
  color: var(--text-primary);
  flex: 1;
}

/* Seven Options */
.seven-options {
  display: flex;
  flex-direction: column;
  gap: 8px;
  margin-top: 16px;
}

.seven-option {
  display: flex;
  align-items: flex-start;
  gap: 12px;
  padding: 12px 16px;
  background: var(--surface);
  border: 1.5px solid var(--outline);
  border-radius: var(--radius-md);
  font-size: 24px;
  line-height: 1.5;
  transition: all 0.2s ease;
}

.seven-option:hover {
  border-color: var(--primary);
  background: var(--tertiary-container);
}

.seven-option strong {
  color: var(--primary);
  font-weight: 700;
  min-width: 28px;
}

/* Gap Fill Exercise */
.gap-fill-item {
  display: flex;
  align-items: baseline;
  gap: var(--space-md);
  margin-bottom: var(--space-md);
  font-size: 24px;
  line-height: 2;
}

.gap-number {
  font-weight: 700;
  color: var(--primary);
  min-width: 40px;
}

.gap-answer {
  color: var(--secondary);
  font-weight: 700;
  border-bottom: 2px solid var(--secondary);
  padding: 0 var(--space-xs);
}

/* ============================================================
   Cloze Grid - Left Article, Right Options
   ============================================================ */
.cloze-grid {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-md);
  align-items: stretch;
  height: calc(100vh - var(--navbar-height) - 280px);
  min-height: 600px;
}

.cloze-grid-large {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: var(--space-lg);
  align-items: stretch;
  height: calc(100vh - var(--navbar-height) - 180px);
  min-height: 700px;
}

/* ---- Scrollable Article Card ---- */
.article-card {
  background: var(--surface);
  border: 1px solid var(--outline-variant);
  border-radius: var(--radius-lg);
  box-shadow: var(--elevation-1);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.article-card-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 18px 24px;
  border-bottom: 1px solid var(--outline-variant);
  background: var(--surface);
  flex-shrink: 0;
}

.article-tag {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  background: var(--primary-container);
  color: var(--primary-on-container);
  padding: 6px 14px;
  border-radius: var(--radius-pill);
  font-size: 14px;
  font-weight: 600;
}

.article-title {
  font-family: var(--font-heading);
  font-size: 22px;
  font-weight: 700;
  color: var(--text-primary);
}

.article-cn {
  font-size: 14px;
  color: var(--text-secondary);
  font-style: italic;
}

.article-card-body {
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-md) var(--space-lg);
  flex: 1;
  scrollbar-width: thin;
  scrollbar-color: var(--outline) transparent;
}

.article-card-body::-webkit-scrollbar { width: 8px; }
.article-card-body::-webkit-scrollbar-track { background: transparent; }
.article-card-body::-webkit-scrollbar-thumb { background: var(--outline); border-radius: 4px; }
.article-card-body::-webkit-scrollbar-thumb:hover { background: var(--primary); }

.article-body {
  font-family: var(--font-reading);
  font-size: 20px;
  line-height: 1.95;
  color: var(--text-primary);
}

.article-body p {
  margin-bottom: var(--space-sm);
  text-align: justify;
}

/* ---- Blank ---- */
.blank {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 56px;
  height: 32px;
  margin: 0 4px;
  padding: 0 10px;
  background: var(--tertiary-container);
  color: var(--primary);
  border: 1.5px dashed var(--primary);
  border-radius: var(--radius-xs);
  font-family: var(--font-heading);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.2, 0, 0, 1);
  position: relative;
  vertical-align: middle;
}

.blank:hover { background: var(--primary); color: white; transform: translateY(-2px); }

.blank.filled {
  background: var(--secondary-container);
  color: var(--on-secondary-container);
  border-color: var(--secondary);
  border-style: solid;
}

.blank.filled.wrong {
  background: var(--error-container);
  color: var(--on-error-container);
  border-color: var(--error);
}

.blank.active {
  background: var(--primary);
  color: white;
  border-color: var(--primary);
  border-style: solid;
  box-shadow: 0 0 0 4px rgba(26, 115, 232, 0.18);
}

.blank-num {
  font-size: 12px;
  margin-right: 4px;
  opacity: 0.75;
}

/* ---- Options Card ---- */
.options-card {
  background: var(--surface);
  border: 1px solid var(--outline-variant);
  border-radius: var(--radius-lg);
  box-shadow: var(--elevation-1);
  display: flex;
  flex-direction: column;
  overflow: hidden;
}

.options-header {
  display: flex;
  align-items: center;
  gap: var(--space-sm);
  padding: 18px 24px;
  border-bottom: 1px solid var(--outline-variant);
  background: var(--surface);
  flex-shrink: 0;
}

.options-icon {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 44px;
  height: 44px;
  background: var(--secondary-container);
  color: var(--on-secondary-container);
  border-radius: var(--radius-sm);
  font-size: 22px;
}

.options-title {
  font-family: var(--font-heading);
  font-size: 20px;
  font-weight: 700;
  color: var(--text-primary);
}

.options-subtitle {
  font-size: 14px;
  color: var(--text-secondary);
}

.options-controls {
  padding: 14px 24px;
  border-bottom: 1px solid var(--outline-variant);
  background: var(--surface);
  flex-shrink: 0;
}

.options-body {
  overflow-y: auto;
  overflow-x: hidden;
  padding: var(--space-md) var(--space-lg);
  flex: 1;
  scrollbar-width: thin;
  scrollbar-color: var(--outline) transparent;
}

.options-body::-webkit-scrollbar { width: 8px; }
.options-body::-webkit-scrollbar-track { background: transparent; }
.options-body::-webkit-scrollbar-thumb { background: var(--outline); border-radius: 4px; }
.options-body::-webkit-scrollbar-thumb:hover { background: var(--primary); }

/* ---- Controls ---- */
.controls {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  border: none;
  font-family: var(--font-heading);
  font-size: 16px;
  font-weight: 600;
  padding: 8px 18px;
  border-radius: var(--radius-pill);
  cursor: pointer;
  transition: all 0.25s cubic-bezier(0.2, 0, 0, 1);
}

.btn-primary {
  background: var(--primary);
  color: white;
}
.btn-primary:hover { background: var(--primary-hover); box-shadow: var(--elevation-1); transform: translateY(-1px); }

.btn-secondary {
  background: var(--secondary-container);
  color: var(--on-secondary-container);
}
.btn-secondary:hover { background: #B7E0C2; transform: translateY(-1px); }

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
  border: 1.5px solid var(--outline);
}
.btn-ghost:hover { background: var(--primary-container); color: var(--primary); border-color: var(--primary); }

/* ---- Option Group ---- */
.option-group {
  display: flex;
  flex-direction: column;
  gap: 8px;
}

.option-group-item {
  margin-bottom: 16px;
}

.option-group-header {
  font-family: var(--font-heading);
  font-size: 14px;
  font-weight: 700;
  color: var(--primary);
  margin-bottom: 8px;
  letter-spacing: 0.5px;
}

.option-group-inner {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 8px;
}

/* ---- Option Item ---- */
.option-item {
  display: grid;
  grid-template-columns: 40px 1fr;
  gap: var(--space-sm);
  align-items: stretch;
  background: var(--surface);
  border: 1.5px solid var(--outline);
  border-radius: var(--radius-md);
  padding: 8px;
  transition: all 0.25s cubic-bezier(0.2, 0, 0, 1);
  cursor: pointer;
}

.option-item:hover {
  border-color: var(--primary);
  background: var(--tertiary-container);
  transform: translateX(4px);
}

.option-item.selected {
  border-color: var(--primary);
  background: var(--primary-container);
}

.option-item.correct {
  border-color: var(--secondary);
  background: var(--secondary-container);
}

.option-item.wrong {
  border-color: var(--error);
  background: var(--error-container);
}

.option-item.disabled { pointer-events: none; opacity: 0.6; }

.option-letter {
  display: flex;
  align-items: center;
  justify-content: center;
  min-width: 40px;
  height: 40px;
  background: var(--primary);
  color: white;
  border-radius: var(--radius-sm);
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 700;
  flex-shrink: 0;
}

.option-item.correct .option-letter { background: var(--secondary); color: white; }
.option-item.wrong .option-letter { background: var(--error); color: white; }

.option-content {
  display: flex;
  flex-direction: column;
  justify-content: center;
  padding: 4px 0;
}

.option-word {
  font-family: var(--font-heading);
  font-size: 24px;
  font-weight: 600;
  color: var(--text-primary);
  line-height: 1.3;
}

.option-zh {
  font-size: 20px;
  color: var(--text-secondary);
  line-height: 1.4;
}

/* ---- Reveal Banner ---- */
.reveal-banner {
  display: none;
  background: linear-gradient(135deg, var(--secondary-container) 0%, #B7E0C2 100%);
  border: 1.5px solid var(--secondary);
  border-radius: var(--radius-md);
  padding: 16px var(--space-md);
  margin: 0 24px 16px;
  align-items: center;
  gap: var(--space-sm);
}

.reveal-banner.show { display: flex; }
.reveal-banner .icon { font-size: 24px; }
.reveal-banner .text { font-family: var(--font-heading); font-size: 14px; font-weight: 600; color: var(--on-secondary-container); }

/* ============================================================
   Cloze Cloze Cloze Cloze Cloze Cloze Cloze Cloze Cloze Cloze
   ============================================================ */

/* Responsive for Options Grid */
@media (max-width: 900px) {
  .option-row {
    flex-direction: column;
  }
}

/* Tab Content */
.tab-content {
  display: none;
}

.tab-content.active {
  display: block;
}

/* Passage Content */
.passage-content {
  margin-top: var(--space-md);
}

/* Navigation between pages */
.page-nav {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-top: var(--space-xxl);
  padding-top: var(--space-lg);
  border-top: 2px solid var(--outline);
}

.page-nav-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-sm);
  padding: var(--space-sm) var(--space-lg);
  background: var(--primary);
  color: white;
  text-decoration: none;
  border-radius: var(--radius-pill);
  font-size: 18px;
  font-weight: 600;
  transition: background 0.2s ease;
}

.page-nav-btn:hover {
  background: var(--primary-hover);
}

.page-nav-btn.secondary {
  background: var(--surface);
  color: var(--primary);
  border: 2px solid var(--primary);
}

.page-nav-btn.secondary:hover {
  background: #E8F0FE;
}

/* Footer */
.footer {
  background: var(--surface);
  border-top: 1px solid var(--outline);
  padding: var(--space-lg);
  text-align: center;
  margin-top: var(--space-xxl);
}

.footer p {
  font-size: 16px;
  color: var(--text-secondary);
}

/* Scroll to top */
.scroll-top {
  position: fixed;
  bottom: var(--space-lg);
  right: var(--space-lg);
  width: 48px;
  height: 48px;
  background: var(--primary);
  color: white;
  border: none;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 20px;
  cursor: pointer;
  box-shadow: var(--shadow-2);
  transition: all 0.2s ease;
  opacity: 0;
  visibility: hidden;
}

.scroll-top.visible {
  opacity: 1;
  visibility: visible;
}

.scroll-top:hover {
  background: var(--primary-hover);
  transform: translateY(-2px);
}

/* Responsive */
@media (max-width: 1024px) {
  .cloze-grid,
  .cloze-grid-large {
    grid-template-columns: 1fr;
    height: auto;
    min-height: auto;
  }
  
  .article-card,
  .options-card {
    min-height: 400px;
    max-height: 70vh;
  }

  .questions-grid {
    grid-template-columns: 1fr;
  }

  .seven-options {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 768px) {
  .navbar-nav {
    display: none;
  }

  .hero h1 {
    font-size: 36px;
  }

  .hero p {
    font-size: 24px;
  }

  .section-title {
    font-size: 28px;
  }

  .question-text,
  .option-text,
  .option-letter,
  .option-word {
    font-size: 20px;
  }

  .container {
    padding: var(--space-md);
  }
}

/* Print styles */
@media print {
  .navbar,
  .scroll-top,
  .answer-toggle,
  .audio-player {
    display: none !important;
  }

  .answer-content {
    display: block !important;
  }

  .main-content {
    margin-top: 0;
  }

  .card,
  .question-item {
    break-inside: avoid;
    box-shadow: none;
    border: 1px solid #ddd;
  }
}

/* Animation */
@keyframes fadeIn {
  from { opacity: 0; transform: translateY(10px); }
  to { opacity: 1; transform: translateY(0); }
}

.card,
.question-item,
.listening-group {
  animation: fadeIn 0.3s ease forwards;
}