/* ===== Design System: telc C1 Hochschule Quiz ===== */
@import url('https://fonts.googleapis.com/css2?family=Inter:wght@300;400;500;600;700;800&display=swap');

/* --- CSS Custom Properties --- */
:root {
  --bg-primary: #0a0e1a;
  --bg-secondary: #111827;
  --bg-card: rgba(30, 41, 59, 0.7);
  --bg-card-hover: rgba(51, 65, 85, 0.7);
  --bg-glass: rgba(255, 255, 255, 0.05);
  --bg-glass-strong: rgba(255, 255, 255, 0.1);
  
  --text-primary: #f1f5f9;
  --text-secondary: #94a3b8;
  --text-muted: #64748b;
  
  --accent-blue: #3b82f6;
  --accent-blue-glow: rgba(59, 130, 246, 0.3);
  --accent-purple: #8b5cf6;
  --accent-purple-glow: rgba(139, 92, 246, 0.3);
  --accent-emerald: #10b981;
  --accent-emerald-glow: rgba(16, 185, 129, 0.2);
  --accent-amber: #f59e0b;
  --accent-rose: #f43f5e;
  
  --gradient-main: linear-gradient(135deg, #3b82f6 0%, #8b5cf6 100%);
  --gradient-card: linear-gradient(145deg, rgba(59, 130, 246, 0.1) 0%, rgba(139, 92, 246, 0.05) 100%);
  --gradient-warm: linear-gradient(135deg, #f59e0b 0%, #f43f5e 100%);
  
  --border-color: rgba(148, 163, 184, 0.1);
  --border-active: rgba(59, 130, 246, 0.5);
  
  --radius-sm: 8px;
  --radius-md: 12px;
  --radius-lg: 16px;
  --radius-xl: 24px;
  
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 12px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 8px 32px rgba(0, 0, 0, 0.5);
  --shadow-glow-blue: 0 0 20px rgba(59, 130, 246, 0.15);
  --shadow-glow-purple: 0 0 20px rgba(139, 92, 246, 0.15);
  
  --transition-fast: 0.15s ease;
  --transition-normal: 0.25s ease;
  --transition-slow: 0.4s cubic-bezier(0.4, 0, 0.2, 1);
  
  --header-height: 64px;
  --max-width: 960px;
}

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

html {
  font-size: 16px;
  scroll-behavior: smooth;
  -webkit-font-smoothing: antialiased;
  -moz-osx-font-smoothing: grayscale;
}

body {
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  background: var(--bg-primary);
  color: var(--text-primary);
  line-height: 1.6;
  min-height: 100vh;
  overflow-x: hidden;
}

/* Animated background */
body::before {
  content: '';
  position: fixed;
  inset: 0;
  background: 
    radial-gradient(ellipse 80% 60% at 20% 10%, rgba(59, 130, 246, 0.08) 0%, transparent 60%),
    radial-gradient(ellipse 60% 50% at 80% 80%, rgba(139, 92, 246, 0.06) 0%, transparent 60%);
  pointer-events: none;
  z-index: 0;
}

/* --- Scrollbar --- */
::-webkit-scrollbar { width: 6px; }
::-webkit-scrollbar-track { background: transparent; }
::-webkit-scrollbar-thumb { background: rgba(148, 163, 184, 0.2); border-radius: 3px; }
::-webkit-scrollbar-thumb:hover { background: rgba(148, 163, 184, 0.4); }

/* --- Header --- */
.app-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  height: var(--header-height);
  background: rgba(10, 14, 26, 0.85);
  backdrop-filter: blur(20px);
  -webkit-backdrop-filter: blur(20px);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 24px;
  z-index: 100;
}

.header-left {
  display: flex;
  align-items: center;
  gap: 16px;
}

.header-logo {
  font-size: 1.1rem;
  font-weight: 700;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  letter-spacing: -0.02em;
  white-space: nowrap;
}

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

/* --- Breadcrumb --- */
.breadcrumb {
  display: flex;
  align-items: center;
  gap: 6px;
  font-size: 0.82rem;
  color: var(--text-muted);
}

.breadcrumb-item {
  cursor: pointer;
  transition: color var(--transition-fast);
  text-decoration: none;
  color: var(--text-muted);
}

.breadcrumb-item:hover { color: var(--text-primary); }
.breadcrumb-item.active { color: var(--text-secondary); cursor: default; }

.breadcrumb-sep {
  font-size: 0.7rem;
  opacity: 0.4;
}

/* --- Timer --- */
.timer-widget {
  display: flex;
  align-items: center;
  gap: 8px;
  background: var(--bg-glass);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-xl);
  padding: 6px 14px;
  font-variant-numeric: tabular-nums;
  user-select: none;
}

.timer-display {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  min-width: 60px;
  text-align: center;
  letter-spacing: 0.05em;
}

.timer-display.running { color: var(--accent-emerald); }

.timer-btn {
  width: 28px;
  height: 28px;
  border-radius: 50%;
  border: none;
  background: var(--bg-glass-strong);
  color: var(--text-secondary);
  cursor: pointer;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 0.75rem;
  transition: all var(--transition-fast);
}

.timer-btn:hover {
  background: var(--accent-blue);
  color: white;
  transform: scale(1.1);
}

.timer-btn svg { width: 14px; height: 14px; fill: currentColor; }

/* --- Main Content --- */
.app-main {
  position: relative;
  z-index: 1;
  padding-top: calc(var(--header-height) + 32px);
  padding-bottom: 48px;
  min-height: 100vh;
}

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0 24px;
}

/* --- Page Transitions --- */
.page-enter { animation: pageIn 0.35s ease-out; }
@keyframes pageIn {
  from { opacity: 0; transform: translateY(16px); }
  to { opacity: 1; transform: translateY(0); }
}

/* --- Home Page --- */
.page-title {
  text-align: center;
  margin-bottom: 48px;
}

.page-title h1 {
  font-size: 2.2rem;
  font-weight: 800;
  background: var(--gradient-main);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
  margin-bottom: 8px;
  letter-spacing: -0.03em;
}

.page-title p {
  font-size: 1rem;
  color: var(--text-muted);
}

/* --- LV Type Cards (Home) --- */
.lv-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(280px, 1fr));
  gap: 20px;
  margin-bottom: 32px;
}

.lv-card {
  position: relative;
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 28px;
  cursor: pointer;
  transition: all var(--transition-normal);
  overflow: hidden;
}

.lv-card::before {
  content: '';
  position: absolute;
  inset: 0;
  background: var(--gradient-card);
  opacity: 0;
  transition: opacity var(--transition-normal);
}

.lv-card:hover {
  border-color: var(--border-active);
  transform: translateY(-3px);
  box-shadow: var(--shadow-glow-blue);
}

.lv-card:hover::before { opacity: 1; }

.lv-card-content {
  position: relative;
  z-index: 1;
}

.lv-card-badge {
  display: inline-block;
  font-size: 0.7rem;
  font-weight: 600;
  text-transform: uppercase;
  letter-spacing: 0.1em;
  background: var(--gradient-main);
  color: white;
  padding: 3px 10px;
  border-radius: var(--radius-sm);
  margin-bottom: 16px;
}

.lv-card h2 {
  font-size: 1.25rem;
  font-weight: 700;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.lv-card .subtitle {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: 12px;
}

.lv-card .desc {
  font-size: 0.82rem;
  color: var(--text-muted);
  margin-bottom: 16px;
  line-height: 1.5;
}

.lv-card .stats {
  display: flex;
  gap: 16px;
  font-size: 0.78rem;
  color: var(--text-muted);
}

.lv-card .stats span {
  display: flex;
  align-items: center;
  gap: 4px;
}

.lv-card.disabled {
  opacity: 0.4;
  cursor: not-allowed;
  pointer-events: none;
}

.lv-card .arrow-icon {
  position: absolute;
  right: 24px;
  top: 50%;
  transform: translateY(-50%);
  font-size: 1.2rem;
  color: var(--text-muted);
  transition: all var(--transition-normal);
}

.lv-card:hover .arrow-icon {
  color: var(--accent-blue);
  transform: translateY(-50%) translateX(4px);
}

/* --- Group List & Question List --- */
.list-header {
  margin-bottom: 24px;
}

.list-header h1 {
  font-size: 1.6rem;
  font-weight: 700;
  margin-bottom: 4px;
  letter-spacing: -0.02em;
}

.list-header p {
  font-size: 0.88rem;
  color: var(--text-muted);
}

.group-card, .question-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 18px 22px;
  margin-bottom: 10px;
  cursor: pointer;
  transition: all var(--transition-normal);
  display: flex;
  align-items: center;
  justify-content: space-between;
}

.group-card:hover, .question-card:hover {
  border-color: var(--border-active);
  background: var(--bg-card-hover);
  transform: translateX(4px);
}

.card-left {
  display: flex;
  align-items: center;
  gap: 14px;
  flex: 1;
  min-width: 0;
}

.card-index {
  width: 36px;
  height: 36px;
  border-radius: var(--radius-sm);
  background: var(--bg-glass-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.85rem;
  color: var(--accent-blue);
  flex-shrink: 0;
}

.card-info h3 {
  font-size: 0.95rem;
  font-weight: 600;
  margin-bottom: 2px;
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
}

.card-info .meta {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.card-right {
  display: flex;
  align-items: center;
  gap: 10px;
  flex-shrink: 0;
}

.status-badge {
  font-size: 0.7rem;
  font-weight: 600;
  padding: 3px 10px;
  border-radius: var(--radius-xl);
  text-transform: uppercase;
  letter-spacing: 0.05em;
}

.status-badge.completed {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  border: 1px solid rgba(16, 185, 129, 0.3);
}

.status-badge.in-progress {
  background: rgba(245, 158, 11, 0.15);
  color: var(--accent-amber);
  border: 1px solid rgba(245, 158, 11, 0.3);
}

.card-arrow {
  color: var(--text-muted);
  font-size: 0.9rem;
  transition: transform var(--transition-fast);
}

.group-card:hover .card-arrow,
.question-card:hover .card-arrow {
  transform: translateX(3px);
  color: var(--accent-blue);
}

/* --- Quiz Page --- */
.quiz-header {
  margin-bottom: 28px;
  padding-bottom: 20px;
  border-bottom: 1px solid var(--border-color);
}

.quiz-header h1 {
  font-size: 1.35rem;
  font-weight: 700;
  margin-bottom: 6px;
  letter-spacing: -0.01em;
}

.quiz-header .quiz-meta {
  font-size: 0.82rem;
  color: var(--text-muted);
  display: flex;
  align-items: center;
  gap: 16px;
}

.copy-btn {
  display: inline-flex;
  align-items: center;
  background: var(--bg-glass-strong);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
  border-radius: var(--radius-sm);
  padding: 4px 10px;
  font-size: 0.75rem;
  cursor: pointer;
  transition: all var(--transition-fast);
  margin-left: auto; /* Push to the right */
}

.copy-btn:hover {
  background: rgba(59, 130, 246, 0.15);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* LV1 Layout */
.quiz-lv1 {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.options-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.options-panel h3 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 14px;
}

.option-chips {
  display: flex;
  flex-wrap: wrap;
  gap: 8px;
}

.option-chip {
  display: inline-block;
  padding: 8px 14px;
  background: var(--bg-glass-strong);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  font-size: 0.82rem;
  line-height: 1.5;
  color: var(--text-primary);
  cursor: default;
  transition: all var(--transition-fast);
  max-width: 100%;
}

.option-chip.used {
  opacity: 0.3;
  text-decoration: line-through;
}

.passages-panel {
  display: flex;
  flex-direction: column;
  gap: 16px;
}

.passage-block {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  padding: 20px;
  transition: border-color var(--transition-normal);
}

.passage-block:hover { border-color: rgba(148, 163, 184, 0.2); }

.passage-text {
  font-size: 0.92rem;
  line-height: 1.75;
  color: var(--text-secondary);
  word-break: break-word;
}

.passage-text .gap-marker {
  display: inline-block;
  margin: 0 4px;
}

.slot-select {
  display: inline-flex;
  align-items: center;
  gap: 4px;
  padding: 4px 12px;
  background: var(--bg-glass-strong);
  border: 1px dashed var(--accent-blue);
  border-radius: var(--radius-sm);
  color: var(--accent-blue);
  cursor: pointer;
  font-size: 0.82rem;
  font-weight: 600;
  transition: all var(--transition-fast);
  vertical-align: middle;
  min-width: 40px;
  text-align: center;
}

.slot-select:hover {
  background: rgba(59, 130, 246, 0.15);
  border-style: solid;
}

.slot-select.filled {
  background: rgba(59, 130, 246, 0.15);
  border-style: solid;
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* LV2 Layout */
.quiz-lv2 {
  display: flex;
  flex-direction: column;
  gap: 24px;
}

.questions-panel {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
}

.questions-panel h3 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
}

.question-row {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  padding: 12px 0;
  border-bottom: 1px solid var(--border-color);
}

.question-row:last-child { border-bottom: none; }

.question-num {
  width: 32px;
  height: 32px;
  border-radius: var(--radius-sm);
  background: var(--bg-glass-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  font-weight: 700;
  font-size: 0.82rem;
  color: var(--accent-purple);
  flex-shrink: 0;
}

.question-text {
  flex: 1;
  font-size: 0.88rem;
  color: var(--text-secondary);
  padding-top: 5px;
}

.answer-select-group {
  display: flex;
  align-items: center;
  gap: 8px;
  flex-shrink: 0;
}

.answer-select {
  padding: 6px 12px;
  background: var(--bg-glass-strong);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  color: var(--text-primary);
  font-size: 0.85rem;
  font-family: 'Inter', sans-serif;
  cursor: pointer;
  appearance: none;
  -webkit-appearance: none;
  min-width: 56px;
  text-align: center;
  transition: all var(--transition-fast);
  flex-shrink: 0;
}

.answer-select:hover {
  border-color: var(--accent-purple);
}

.answer-select:focus {
  outline: none;
  border-color: var(--accent-purple);
  box-shadow: 0 0 0 3px var(--accent-purple-glow);
}

.answer-select.answered {
  background: rgba(139, 92, 246, 0.15);
  border-color: var(--accent-purple);
  color: var(--accent-purple);
  font-weight: 600;
}

.passage-card {
  background: var(--bg-card);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-md);
  overflow: hidden;
  transition: all var(--transition-normal);
}

.passage-card.highlighted {
  border-color: var(--accent-purple);
  box-shadow: var(--shadow-glow-purple);
}

.passage-card-header {
  padding: 14px 20px;
  background: var(--bg-glass);
  border-bottom: 1px solid var(--border-color);
  display: flex;
  align-items: center;
  justify-content: space-between;
  cursor: pointer;
  user-select: none;
}

.passage-card-header h4 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-primary);
  display: flex;
  align-items: center;
  gap: 8px;
}

.passage-card-header .toggle-icon {
  font-size: 0.75rem;
  color: var(--text-muted);
  transition: transform var(--transition-fast);
}

.passage-card-header .toggle-icon.open { transform: rotate(90deg); }

.passage-card-body {
  padding: 20px;
  font-size: 0.9rem;
  line-height: 1.8;
  color: var(--text-secondary);
  display: none;
}

.passage-card-body.open { display: block; }

/* --- Dropdown / Option Picker Modal --- */
.option-picker-overlay {
  position: fixed;
  inset: 0;
  background: rgba(0, 0, 0, 0.6);
  backdrop-filter: blur(4px);
  z-index: 200;
  display: flex;
  align-items: center;
  justify-content: center;
  animation: fadeIn 0.15s ease;
}

@keyframes fadeIn {
  from { opacity: 0; }
  to { opacity: 1; }
}

.option-picker {
  background: var(--bg-secondary);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  width: min(460px, 92vw);
  max-height: 80vh;
  overflow-y: auto;
  box-shadow: var(--shadow-lg);
  animation: scaleIn 0.2s ease;
}

@keyframes scaleIn {
  from { opacity: 0; transform: scale(0.95); }
  to { opacity: 1; transform: scale(1); }
}

.option-picker h3 {
  font-size: 0.9rem;
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: 14px;
}

.picker-option {
  padding: 12px 16px;
  border: 1px solid var(--border-color);
  border-radius: var(--radius-sm);
  margin-bottom: 8px;
  cursor: pointer;
  font-size: 0.85rem;
  line-height: 1.5;
  color: var(--text-primary);
  transition: all var(--transition-fast);
}

.picker-option:hover {
  background: rgba(59, 130, 246, 0.1);
  border-color: var(--accent-blue);
}

.picker-option.used {
  opacity: 0.35;
  cursor: not-allowed;
}

.picker-option.selected {
  background: rgba(59, 130, 246, 0.15);
  border-color: var(--accent-blue);
  color: var(--accent-blue);
}

/* --- Grading & Accuracy (核对答案) --- */
.grading-panel {
  background: rgba(10, 14, 26, 0.4);
  border: 1px solid var(--border-color);
  border-radius: var(--radius-lg);
  padding: 20px;
  margin-top: 32px;
}

.grading-panel h3 {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-secondary);
  text-transform: uppercase;
  letter-spacing: 0.08em;
  margin-bottom: 16px;
  display: flex;
  justify-content: space-between;
  align-items: center;
}

.grading-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 12px 16px;
  border-bottom: 1px dashed var(--border-color);
  background: var(--bg-glass);
  margin-bottom: 8px;
  border-radius: var(--radius-sm);
}

.grading-row:last-child {
  border-bottom: none;
  margin-bottom: 0;
}

.grading-label {
  font-size: 0.85rem;
  font-weight: 600;
  color: var(--text-primary);
  width: 60px;
}

.grading-my-ans {
  font-size: 0.85rem;
  color: var(--text-muted);
  flex: 1;
}

.grading-my-ans span {
  display: inline-block;
  padding: 2px 8px;
  background: var(--bg-glass-strong);
  border-radius: 4px;
  color: var(--accent-blue);
  font-weight: 600;
}

.grading-corr-ans {
  display: flex;
  align-items: center;
  gap: 8px;
}

.grading-corr-ans span {
  font-size: 0.8rem;
  color: var(--text-muted);
}

/* Correct/Incorrect Highlight */
.answer-select.correct, .grading-row.correct {
  border-color: var(--accent-emerald) !important;
  box-shadow: inset 0 0 0 1px rgba(16, 185, 129, 0.2);
}
.answer-select.incorrect, .grading-row.incorrect {
  border-color: var(--accent-rose) !important;
  box-shadow: inset 0 0 0 1px rgba(244, 63, 94, 0.2);
}

/* Correct Answer Dropdown Variations */
.answer-select.correct-input {
  border-style: dashed;
}
.answer-select.correct-input:focus {
  border-style: solid;
}

/* Accuracy Badges */
.status-badge.accuracy {
  background: var(--bg-glass-strong);
  border: 1px solid var(--border-color);
  color: var(--text-primary);
}
.status-badge.accuracy.perfect {
  background: rgba(16, 185, 129, 0.15);
  color: var(--accent-emerald);
  border-color: rgba(16, 185, 129, 0.3);
}
.status-badge.accuracy.poor {
  background: rgba(244, 63, 94, 0.1);
  color: var(--accent-rose);
  border-color: rgba(244, 63, 94, 0.2);
}

/* Progress Accuracy Text */
.progress-accuracy {
  font-weight: 600;
  color: var(--accent-emerald);
  display: inline-flex;
  align-items: center;
  gap: 4px;
}
.progress-accuracy.poor {
  color: var(--accent-rose);
}

.picker-clear {
  padding: 10px 16px;
  border: 1px dashed var(--border-color);
  border-radius: var(--radius-sm);
  cursor: pointer;
  font-size: 0.82rem;
  color: var(--text-muted);
  text-align: center;
  transition: all var(--transition-fast);
  margin-bottom: 8px;
}

.picker-clear:hover {
  border-color: var(--accent-rose);
  color: var(--accent-rose);
}

/* --- Back Button --- */
.back-btn {
  display: inline-flex;
  align-items: center;
  gap: 6px;
  color: var(--text-muted);
  font-size: 0.85rem;
  cursor: pointer;
  padding: 6px 0;
  margin-bottom: 16px;
  transition: color var(--transition-fast);
  border: none;
  background: none;
  font-family: inherit;
}

.back-btn:hover { color: var(--text-primary); }

/* --- Progress Bar --- */
.progress-bar-container {
  margin-top: 20px;
  margin-bottom: 8px;
}

.progress-bar-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.78rem;
  color: var(--text-muted);
  margin-bottom: 6px;
}

.progress-bar {
  height: 4px;
  background: var(--bg-glass-strong);
  border-radius: 2px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--gradient-main);
  border-radius: 2px;
  transition: width var(--transition-slow);
}

/* --- Save Status --- */
.save-indicator {
  position: fixed;
  bottom: 24px;
  right: 24px;
  background: rgba(16, 185, 129, 0.9);
  color: white;
  padding: 8px 16px;
  border-radius: var(--radius-xl);
  font-size: 0.78rem;
  font-weight: 600;
  opacity: 0;
  transform: translateY(10px);
  transition: all var(--transition-normal);
  z-index: 300;
  pointer-events: none;
}

.save-indicator.show {
  opacity: 1;
  transform: translateY(0);
}

/* --- Responsive --- */
@media (max-width: 640px) {
  .app-header { padding: 0 16px; }
  .container { padding: 0 16px; }
  .page-title h1 { font-size: 1.7rem; }
  .lv-grid { grid-template-columns: 1fr; }
  .header-logo { font-size: 0.95rem; }
  .breadcrumb { display: none; }
  .quiz-header h1 { font-size: 1.15rem; }
  .option-chip { font-size: 0.78rem; }
  .timer-widget { padding: 4px 10px; }
  
  .question-row {
    flex-direction: column;
    gap: 8px;
  }
  
  .answer-select {
    align-self: flex-start;
  }
}