/* ========================================
   U.S. Citizenship Test Prep — Base Styles
   ======================================== */

/* CSS Variables — Design Tokens */
:root {
  /* Colors */
  --color-primary: #1B2A4A;
  --color-primary-light: #2A3F6B;
  --color-primary-dark: #111D35;
  --color-white: #FFFFFF;
  --color-gold: #C9A94E;
  --color-gold-light: #E0C76E;
  --color-success: #22C55E;
  --color-success-light: #BBF7D0;
  --color-error: #EF4444;
  --color-error-light: #FECACA;
  --color-warning: #F59E0B;
  --color-info: #3B82F6;

  /* Backgrounds */
  --bg-primary: #F8FAFC;
  --bg-secondary: #FFFFFF;
  --bg-card: #FFFFFF;
  --bg-input: #F1F5F9;
  --bg-nav: #FFFFFF;
  --bg-header: #1B2A4A;

  /* Text */
  --text-primary: #0F172A;
  --text-secondary: #475569;
  --text-muted: #94A3B8;
  --text-on-primary: #FFFFFF;
  --text-on-gold: #1B2A4A;

  /* Borders */
  --border-color: #E2E8F0;
  --border-color-light: #F1F5F9;

  /* Shadows */
  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.05);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.1), 0 2px 4px -2px rgba(0, 0, 0, 0.1);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.1), 0 4px 6px -4px rgba(0, 0, 0, 0.1);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.08), 0 1px 2px rgba(0, 0, 0, 0.06);

  /* Spacing (8px grid) */
  --space-1: 4px;
  --space-2: 8px;
  --space-3: 12px;
  --space-4: 16px;
  --space-5: 20px;
  --space-6: 24px;
  --space-8: 32px;
  --space-10: 40px;
  --space-12: 48px;

  /* Border Radius */
  --radius-sm: 6px;
  --radius-md: 8px;
  --radius-lg: 12px;
  --radius-xl: 16px;
  --radius-full: 9999px;

  /* Typography */
  --font-sans: -apple-system, BlinkMacSystemFont, 'Segoe UI', 'Inter', Roboto, Oxygen, Ubuntu, sans-serif;
  --font-mono: 'SF Mono', SFMono-Regular, Consolas, 'Liberation Mono', Menlo, monospace;

  /* Font Sizes */
  --text-xs: 0.75rem;
  --text-sm: 0.875rem;
  --text-base: 1rem;
  --text-lg: 1.125rem;
  --text-xl: 1.25rem;
  --text-2xl: 1.5rem;
  --text-3xl: 1.875rem;

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

  /* Layout */
  --header-height: 56px;
  --nav-height: 64px;
  --max-width: 600px;
}

/* Dark Mode */
[data-theme="dark"] {
  --bg-primary: #0F172A;
  --bg-secondary: #1E293B;
  --bg-card: #1E293B;
  --bg-input: #334155;
  --bg-nav: #1E293B;
  --bg-header: #0F172A;

  --text-primary: #F1F5F9;
  --text-secondary: #94A3B8;
  --text-muted: #64748B;

  --border-color: #334155;
  --border-color-light: #1E293B;

  --shadow-sm: 0 1px 2px rgba(0, 0, 0, 0.3);
  --shadow-md: 0 4px 6px -1px rgba(0, 0, 0, 0.4);
  --shadow-lg: 0 10px 15px -3px rgba(0, 0, 0, 0.4);
  --shadow-card: 0 1px 3px rgba(0, 0, 0, 0.3);
}

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

html {
  font-size: 16px;
  -webkit-text-size-adjust: 100%;
  -webkit-tap-highlight-color: transparent;
}

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

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

a:hover {
  text-decoration: underline;
}

img {
  max-width: 100%;
  display: block;
}

/* Focus indicators for accessibility */
:focus-visible {
  outline: 2px solid var(--color-gold);
  outline-offset: 2px;
}

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

/* ========================================
   Layout
   ======================================== */
.app-container {
  display: flex;
  flex-direction: column;
  min-height: 100vh;
  max-width: var(--max-width);
  margin: 0 auto;
}

/* Header */
.app-header {
  position: sticky;
  top: 0;
  z-index: 100;
  background: var(--bg-header);
  color: var(--text-on-primary);
  height: var(--header-height);
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 0 var(--space-4);
  box-shadow: var(--shadow-md);
}

.app-header h1 {
  font-size: var(--text-lg);
  font-weight: 700;
  letter-spacing: -0.01em;
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.app-header h1 .flag-icon {
  font-size: var(--text-xl);
}

.header-actions {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.header-btn {
  background: none;
  border: none;
  color: var(--text-on-primary);
  cursor: pointer;
  padding: var(--space-2);
  border-radius: var(--radius-md);
  font-size: var(--text-xl);
  transition: background var(--transition-fast);
  display: flex;
  align-items: center;
  justify-content: center;
  width: 40px;
  height: 40px;
}

.header-btn:hover {
  background: rgba(255, 255, 255, 0.15);
}

/* Main Content */
#main-content {
  flex: 1;
  padding: var(--space-4);
  padding-bottom: calc(var(--nav-height) + var(--space-4));
}

/* Page transitions */
.page-exit {
  opacity: 0;
  transform: translateY(8px);
  transition: opacity var(--transition-fast), transform var(--transition-fast);
}

.page-enter {
  animation: fadeSlideIn var(--transition-normal) ease forwards;
}

@keyframes fadeSlideIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Bottom Navigation */
.bottom-nav {
  position: fixed;
  bottom: 0;
  left: 0;
  right: 0;
  z-index: 100;
  background: var(--bg-nav);
  height: var(--nav-height);
  display: flex;
  align-items: center;
  justify-content: space-around;
  box-shadow: 0 -1px 3px rgba(0, 0, 0, 0.1);
  border-top: 1px solid var(--border-color);
  max-width: var(--max-width);
  margin: 0 auto;
}

.nav-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  gap: 2px;
  padding: var(--space-1) var(--space-3);
  border: none;
  background: none;
  cursor: pointer;
  color: var(--text-muted);
  font-size: var(--text-xs);
  font-weight: 500;
  transition: color var(--transition-fast);
  min-width: 60px;
  -webkit-tap-highlight-color: transparent;
}

.nav-item .nav-icon {
  font-size: 22px;
  line-height: 1;
}

.nav-item.active {
  color: var(--color-primary);
}

[data-theme="dark"] .nav-item.active {
  color: var(--color-gold);
}

.nav-item:hover {
  color: var(--color-primary);
}

/* ========================================
   Common Components
   ======================================== */

/* Cards */
.card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-color-light);
}

.card + .card {
  margin-top: var(--space-3);
}

/* Buttons */
.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: var(--text-base);
  font-weight: 600;
  border: none;
  cursor: pointer;
  transition: all var(--transition-fast);
  min-height: 48px;
  min-width: 48px;
  text-decoration: none;
  line-height: 1.2;
}

.btn:active {
  transform: scale(0.97);
}

.btn-primary {
  background: var(--color-primary);
  color: var(--text-on-primary);
}

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

.btn-gold {
  background: var(--color-gold);
  color: var(--text-on-gold);
}

.btn-gold:hover {
  background: var(--color-gold-light);
}

.btn-success {
  background: var(--color-success);
  color: white;
}

.btn-error {
  background: var(--color-error);
  color: white;
}

.btn-outline {
  background: transparent;
  color: var(--text-primary);
  border: 2px solid var(--border-color);
}

.btn-outline:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.btn-ghost {
  background: transparent;
  color: var(--text-secondary);
}

.btn-ghost:hover {
  background: var(--bg-input);
}

.btn-sm {
  padding: var(--space-2) var(--space-3);
  font-size: var(--text-sm);
  min-height: 36px;
}

.btn-lg {
  padding: var(--space-4) var(--space-6);
  font-size: var(--text-lg);
}

.btn-block {
  display: flex;
  width: 100%;
}

/* Progress Bar */
.progress-bar {
  width: 100%;
  height: 8px;
  background: var(--bg-input);
  border-radius: var(--radius-full);
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  background: var(--color-gold);
  border-radius: var(--radius-full);
  transition: width var(--transition-slow);
}

.progress-bar-fill.green {
  background: var(--color-success);
}

/* Badge */
.badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: 2px var(--space-2);
  border-radius: var(--radius-full);
  font-size: var(--text-xs);
  font-weight: 600;
  line-height: 1.4;
}

.badge-gold {
  background: rgba(201, 169, 78, 0.15);
  color: var(--color-gold);
}

.badge-success {
  background: var(--color-success-light);
  color: #15803D;
}

.badge-error {
  background: var(--color-error-light);
  color: #B91C1C;
}

/* Section Headers */
.section-title {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--text-primary);
  margin-bottom: var(--space-3);
}

.section-subtitle {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-top: var(--space-1);
}

/* Stat Grid */
.stat-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-3);
}

.stat-item {
  text-align: center;
  padding: var(--space-3);
}

.stat-value {
  font-size: var(--text-2xl);
  font-weight: 700;
  color: var(--color-primary);
}

[data-theme="dark"] .stat-value {
  color: var(--color-gold);
}

.stat-label {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  margin-top: var(--space-1);
}

/* Action Cards (home screen) */
.action-card {
  display: flex;
  align-items: center;
  gap: var(--space-4);
  padding: var(--space-4);
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-color-light);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-decoration: none;
  color: inherit;
}

.action-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
  text-decoration: none;
  color: inherit;
}

.action-card + .action-card {
  margin-top: var(--space-3);
}

.action-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}

.action-card-icon.blue { background: rgba(59, 130, 246, 0.1); }
.action-card-icon.green { background: rgba(34, 197, 94, 0.1); }
.action-card-icon.gold { background: rgba(201, 169, 78, 0.1); }
.action-card-icon.red { background: rgba(239, 68, 68, 0.1); }

.action-card-text h3 {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--text-primary);
}

.action-card-text p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Empty State */
.empty-state {
  text-align: center;
  padding: var(--space-10) var(--space-4);
  color: var(--text-muted);
}

.empty-state .emoji {
  font-size: 48px;
  margin-bottom: var(--space-3);
}

/* ========================================
   Screen reader only
   ======================================== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  border: 0;
}

/* ========================================
   Utility Classes
   ======================================== */
.text-center { text-align: center; }
.text-sm { font-size: var(--text-sm); }
.text-muted { color: var(--text-secondary); }
.mt-2 { margin-top: var(--space-2); }
.mt-3 { margin-top: var(--space-3); }
.mt-4 { margin-top: var(--space-4); }
.mt-6 { margin-top: var(--space-6); }
.mb-3 { margin-bottom: var(--space-3); }
.mb-4 { margin-bottom: var(--space-4); }
.gap-2 { gap: var(--space-2); }
.gap-3 { gap: var(--space-3); }
.flex { display: flex; }
.flex-col { flex-direction: column; }
.items-center { align-items: center; }
.justify-between { justify-content: space-between; }
.justify-center { justify-content: center; }
.w-full { width: 100%; }

/* ========================================
   Study Mode — Flashcards
   ======================================== */

/* Study Landing / Category Overview */
.study-categories {
  display: grid;
  gap: var(--space-3);
}

.category-card {
  background: var(--bg-card);
  border-radius: var(--radius-lg);
  padding: var(--space-4);
  box-shadow: var(--shadow-card);
  border: 1px solid var(--border-color-light);
  cursor: pointer;
  transition: all var(--transition-fast);
  display: flex;
  align-items: center;
  gap: var(--space-4);
}

.category-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.category-card-icon {
  width: 48px;
  height: 48px;
  border-radius: var(--radius-md);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 24px;
  flex-shrink: 0;
}

.category-card-text {
  flex: 1;
  min-width: 0;
}

.category-card-text h3 {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--text-primary);
}

.category-card-text p {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  margin-top: 2px;
}

.category-progress {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-top: var(--space-2);
}

.category-progress-text {
  font-size: var(--text-xs);
  color: var(--text-muted);
  white-space: nowrap;
}

.category-progress .progress-bar {
  height: 6px;
  flex: 1;
}

/* Study Controls Bar */
.study-controls {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
  flex-wrap: wrap;
}

.study-controls-left {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.study-controls-right {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.study-back-btn {
  background: none;
  border: none;
  cursor: pointer;
  color: var(--text-secondary);
  font-size: var(--text-lg);
  padding: var(--space-1);
  border-radius: var(--radius-sm);
  display: flex;
  align-items: center;
  transition: color var(--transition-fast);
}

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

.study-filter-label {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.toggle-btn {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-full);
  border: 1.5px solid var(--border-color);
  background: var(--bg-card);
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  white-space: nowrap;
}

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

.toggle-btn.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--text-on-primary);
}

[data-theme="dark"] .toggle-btn.active {
  background: var(--color-gold);
  border-color: var(--color-gold);
  color: var(--text-on-gold);
}

/* Question Counter + Progress */
.study-progress-bar {
  margin-bottom: var(--space-3);
}

.study-progress-info {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-1);
}

.study-progress-counter {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
}

/* Mastery Indicator */
.mastery-dot {
  display: inline-block;
  width: 10px;
  height: 10px;
  border-radius: 50%;
  margin-right: var(--space-1);
  vertical-align: middle;
}

.mastery-dot.not-seen { background: var(--color-error); }
.mastery-dot.seen { background: var(--color-warning); }
.mastery-dot.learned { background: var(--color-success); }

.mastery-label {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* Flashcard Container */
.flashcard-wrapper {
  perspective: 1200px;
  margin-bottom: var(--space-4);
  /* Prevent wrapper from collapsing during flip */
  min-height: 220px;
}

.flashcard {
  position: relative;
  width: 100%;
  min-height: 220px;
  cursor: pointer;
  transform-style: preserve-3d;
  transition: transform 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  -webkit-tap-highlight-color: transparent;
}

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

.flashcard-face {
  width: 100%;
  min-height: 220px;
  backface-visibility: hidden;
  -webkit-backface-visibility: hidden;
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  display: flex;
  flex-direction: column;
  box-shadow: var(--shadow-md);
  border: 1px solid var(--border-color-light);
}

.flashcard-front {
  position: relative;
  background: var(--bg-card);
  justify-content: center;
  align-items: center;
  text-align: center;
}

.flashcard-back {
  position: absolute;
  top: 0;
  left: 0;
  background: var(--color-primary);
  color: var(--text-on-primary);
  transform: rotateY(180deg);
  justify-content: center;
}

[data-theme="dark"] .flashcard-back {
  background: #2A3F6B;
}

.flashcard-question-number {
  position: absolute;
  top: var(--space-3);
  left: var(--space-4);
  font-size: var(--text-xs);
  font-weight: 600;
  opacity: 0.5;
}

.flashcard-tap-hint {
  position: absolute;
  bottom: var(--space-3);
  right: var(--space-4);
  font-size: var(--text-xs);
  opacity: 0.4;
}

.flashcard-question {
  font-size: var(--text-lg);
  font-weight: 600;
  line-height: 1.5;
  color: var(--text-primary);
}

.flashcard-subcategory {
  position: absolute;
  top: var(--space-3);
  right: var(--space-4);
  font-size: var(--text-xs);
  font-weight: 500;
  opacity: 0.6;
  max-width: 50%;
  text-align: right;
}

.flashcard-answers {
  margin-bottom: var(--space-3);
}

.flashcard-answer-item {
  font-size: var(--text-base);
  font-weight: 600;
  line-height: 1.6;
  padding: var(--space-1) 0;
  border-bottom: 1px solid rgba(255, 255, 255, 0.15);
}

.flashcard-answer-item:last-child {
  border-bottom: none;
}

.flashcard-answer-label {
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.05em;
  opacity: 0.7;
  margin-bottom: var(--space-2);
}

.flashcard-explanation {
  font-size: var(--text-sm);
  opacity: 0.8;
  line-height: 1.5;
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid rgba(255, 255, 255, 0.15);
}

/* Navigation Buttons */
.flashcard-nav {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  margin-bottom: var(--space-3);
}

.nav-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 48px;
  height: 48px;
  border-radius: var(--radius-full);
  border: 2px solid var(--border-color);
  background: var(--bg-card);
  color: var(--text-primary);
  font-size: var(--text-lg);
  cursor: pointer;
  transition: all var(--transition-fast);
}

.nav-btn:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
  background: var(--bg-card);
}

.nav-btn:active {
  transform: scale(0.93);
}

.nav-btn.random-btn {
  font-size: var(--text-sm);
  width: auto;
  padding: 0 var(--space-4);
  font-weight: 600;
}

/* Mastery Action Buttons */
.mastery-actions {
  display: flex;
  gap: var(--space-2);
  justify-content: center;
}

.mastery-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  border: 2px solid var(--border-color);
  background: var(--bg-card);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  min-height: 44px;
}

.mastery-btn:hover {
  border-color: var(--color-success);
  color: var(--color-success);
}

.mastery-btn.is-learned {
  background: var(--color-success);
  border-color: var(--color-success);
  color: white;
}

.mastery-btn.is-learned:hover {
  background: var(--color-error);
  border-color: var(--color-error);
  color: white;
}

/* Mastery Legend */
.mastery-legend {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  margin-top: var(--space-4);
  padding-top: var(--space-3);
  border-top: 1px solid var(--border-color-light);
}

.mastery-legend-item {
  display: flex;
  align-items: center;
  gap: var(--space-1);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* Swipe hint animation */
@keyframes swipeHint {
  0%, 100% { transform: translateX(0); opacity: 0.4; }
  50% { transform: translateX(-5px); opacity: 0.7; }
}

.swipe-hint {
  animation: swipeHint 2s ease-in-out infinite;
}

/* ========================================
   Practice Quiz Engine
   ======================================== */

/* Quiz Setup Screen */
.quiz-setup-label {
  display: block;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.quiz-setup-options {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
}

.quiz-chip {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  border: 2px solid var(--border-color);
  background: var(--bg-card);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
  cursor: pointer;
  transition: all var(--transition-fast);
  min-height: 40px;
  font-family: var(--font-sans);
}

.quiz-chip:hover {
  border-color: var(--color-primary);
  color: var(--color-primary);
}

.quiz-chip.active {
  background: var(--color-primary);
  border-color: var(--color-primary);
  color: var(--text-on-primary);
}

[data-theme="dark"] .quiz-chip.active {
  background: var(--color-gold);
  border-color: var(--color-gold);
  color: var(--text-on-gold);
}

/* Quiz History List (setup screen) */
.quiz-history-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.quiz-history-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--border-color-light);
}

.quiz-history-item:last-child {
  border-bottom: none;
}

.quiz-history-score {
  font-size: var(--text-base);
  font-weight: 700;
  min-width: 48px;
  text-align: center;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
}

.quiz-history-score.pass {
  background: var(--color-success-light);
  color: #15803D;
}

.quiz-history-score.fail {
  background: var(--color-error-light);
  color: #B91C1C;
}

.quiz-history-detail {
  display: flex;
  flex-direction: column;
}

.quiz-history-pct {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.quiz-history-meta {
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* Quiz Progress Bar (during quiz) */
.quiz-progress {
  margin-bottom: var(--space-3);
}

.quiz-progress-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  margin-bottom: var(--space-1);
}

.quiz-progress-text {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
}

.quiz-progress-score {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-primary);
}

[data-theme="dark"] .quiz-progress-score {
  color: var(--color-gold);
}

/* Quiz Question Text */
.quiz-question-text {
  font-size: var(--text-lg);
  font-weight: 600;
  line-height: 1.5;
  color: var(--text-primary);
}

/* Quiz Answer Options */
.quiz-options {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.quiz-option {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  width: 100%;
  min-height: 48px;
  padding: var(--space-3) var(--space-4);
  border-radius: var(--radius-lg);
  border: 2px solid var(--border-color);
  background: var(--bg-card);
  cursor: pointer;
  transition: all var(--transition-fast);
  text-align: left;
  font-family: var(--font-sans);
  font-size: var(--text-base);
  color: var(--text-primary);
  -webkit-tap-highlight-color: transparent;
}

.quiz-option:hover:not(.disabled) {
  border-color: var(--color-primary);
  background: var(--bg-input);
  transform: translateY(-1px);
  box-shadow: var(--shadow-sm);
}

.quiz-option:active:not(.disabled) {
  transform: scale(0.98);
}

.quiz-option-letter {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  background: var(--bg-input);
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--text-secondary);
  flex-shrink: 0;
  transition: all var(--transition-fast);
}

.quiz-option-text {
  flex: 1;
  line-height: 1.4;
}

/* Answer states */
.quiz-option.correct {
  border-color: var(--color-success);
  background: var(--color-success-light);
}

.quiz-option.correct .quiz-option-letter {
  background: var(--color-success);
  color: white;
}

[data-theme="dark"] .quiz-option.correct {
  border-color: var(--color-success);
  background: rgba(34, 197, 94, 0.15);
}

.quiz-option.wrong {
  border-color: var(--color-error);
  background: var(--color-error-light);
}

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

[data-theme="dark"] .quiz-option.wrong {
  border-color: var(--color-error);
  background: rgba(239, 68, 68, 0.15);
}

.quiz-option.disabled {
  cursor: default;
  pointer-events: none;
}

/* Feedback Panel */
.quiz-feedback {
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  margin-top: var(--space-3);
  animation: fadeSlideIn var(--transition-normal) ease forwards;
}

.quiz-feedback-correct {
  background: var(--color-success-light);
  border: 1px solid var(--color-success);
}

[data-theme="dark"] .quiz-feedback-correct {
  background: rgba(34, 197, 94, 0.12);
  border-color: rgba(34, 197, 94, 0.4);
}

.quiz-feedback-wrong {
  background: var(--color-error-light);
  border: 1px solid var(--color-error);
}

[data-theme="dark"] .quiz-feedback-wrong {
  background: rgba(239, 68, 68, 0.12);
  border-color: rgba(239, 68, 68, 0.4);
}

.quiz-feedback-icon {
  font-size: var(--text-lg);
  font-weight: 700;
  margin-bottom: var(--space-2);
}

.quiz-feedback-correct .quiz-feedback-icon {
  color: #15803D;
}

[data-theme="dark"] .quiz-feedback-correct .quiz-feedback-icon {
  color: var(--color-success);
}

.quiz-feedback-wrong .quiz-feedback-icon {
  color: #B91C1C;
}

[data-theme="dark"] .quiz-feedback-wrong .quiz-feedback-icon {
  color: var(--color-error);
}

.quiz-feedback-explanation {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.5;
}

/* Quiz Results Screen */
.quiz-results-score {
  font-size: 3rem;
  font-weight: 800;
  color: var(--color-primary);
  line-height: 1.1;
}

[data-theme="dark"] .quiz-results-score {
  color: var(--color-gold);
}

.quiz-results-pct {
  font-size: var(--text-2xl);
  font-weight: 600;
  color: var(--text-secondary);
  margin-top: var(--space-1);
}

.quiz-results-feedback {
  font-size: var(--text-xl);
  font-weight: 700;
  margin-top: var(--space-2);
}

.quiz-results-feedback.excellent { color: var(--color-success); }
.quiz-results-feedback.great { color: var(--color-success); }
.quiz-results-feedback.good { color: var(--color-info); }
.quiz-results-feedback.keep-going { color: var(--color-warning); }
.quiz-results-feedback.needs-work { color: var(--color-error); }

.quiz-results-pass-ref {
  display: inline-block;
  margin-top: var(--space-3);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  font-size: var(--text-sm);
  font-weight: 600;
}

.quiz-results-pass-ref.pass {
  background: var(--color-success-light);
  color: #15803D;
}

[data-theme="dark"] .quiz-results-pass-ref.pass {
  background: rgba(34, 197, 94, 0.15);
  color: var(--color-success);
}

.quiz-results-pass-ref.fail {
  background: var(--color-error-light);
  color: #B91C1C;
}

[data-theme="dark"] .quiz-results-pass-ref.fail {
  background: rgba(239, 68, 68, 0.15);
  color: var(--color-error);
}

/* Quiz Results Actions */
.quiz-results-actions {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

/* Missed Questions List */
.quiz-missed-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.quiz-missed-item {
  padding: var(--space-3);
  border-radius: var(--radius-md);
  background: var(--bg-input);
  border-left: 3px solid var(--color-error);
}

.quiz-missed-question {
  font-size: var(--text-base);
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-2);
  line-height: 1.4;
}

.quiz-missed-label {
  font-weight: 600;
  font-size: var(--text-xs);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.quiz-missed-your-answer {
  font-size: var(--text-sm);
  color: var(--color-error);
  margin-bottom: var(--space-1);
}

.quiz-missed-correct-answer {
  font-size: var(--text-sm);
  color: var(--color-success);
  margin-bottom: var(--space-1);
}

[data-theme="dark"] .quiz-missed-your-answer {
  color: #FCA5A5;
}

[data-theme="dark"] .quiz-missed-correct-answer {
  color: #86EFAC;
}

.quiz-missed-explanation {
  font-size: var(--text-xs);
  color: var(--text-muted);
  line-height: 1.5;
  margin-top: var(--space-2);
  padding-top: var(--space-2);
  border-top: 1px solid var(--border-color-light);
}

/* ========================================
   Test Simulation
   ======================================== */

/* Test Info Box */
.test-info-box {
  display: flex;
  gap: var(--space-3);
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--bg-input);
  border-left: 4px solid var(--color-gold);
}

.test-info-icon {
  font-size: 28px;
  flex-shrink: 0;
}

.test-info-title {
  font-weight: 700;
  font-size: var(--text-sm);
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

.test-info-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.test-info-list li {
  font-size: var(--text-sm);
  color: var(--text-secondary);
  line-height: 1.6;
  padding-left: var(--space-4);
  position: relative;
}

.test-info-list li::before {
  content: '•';
  position: absolute;
  left: var(--space-2);
  color: var(--color-gold);
  font-weight: 700;
}

/* Score Dots */
.test-score-dots {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: 6px;
  flex-wrap: wrap;
}

.test-dot {
  display: flex;
  align-items: center;
  justify-content: center;
  width: 32px;
  height: 32px;
  border-radius: var(--radius-full);
  border: 2px solid var(--border-color);
  background: var(--bg-card);
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--text-muted);
  transition: all var(--transition-fast);
}

.test-dot.current {
  border-color: var(--color-gold);
  background: var(--color-gold);
  color: var(--text-on-gold);
  transform: scale(1.1);
}

.test-dot.correct {
  border-color: var(--color-success);
  background: var(--color-success);
  color: white;
}

.test-dot.wrong {
  border-color: var(--color-error);
  background: var(--color-error);
  color: white;
}

/* Timer */
.test-timer {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-full);
  background: var(--bg-input);
  margin-bottom: var(--space-3);
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-secondary);
  transition: all var(--transition-fast);
}

.test-timer.urgent {
  background: var(--color-error-light);
  color: var(--color-error);
  animation: pulse 1s infinite;
}

[data-theme="dark"] .test-timer.urgent {
  background: rgba(239, 68, 68, 0.15);
  color: #FCA5A5;
}

@keyframes pulse {
  0%, 100% { transform: scale(1); }
  50% { transform: scale(1.05); }
}

.test-timer-value {
  font-size: var(--text-xl);
  font-weight: 800;
  min-width: 28px;
  text-align: center;
}

/* Answer Input */
.test-input-area {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.test-answer-input {
  width: 100%;
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  border: 2px solid var(--border-color);
  background: var(--bg-card);
  font-size: var(--text-lg);
  font-family: var(--font-sans);
  color: var(--text-primary);
  transition: all var(--transition-fast);
  box-sizing: border-box;
}

.test-answer-input:focus {
  outline: none;
  border-color: var(--color-gold);
  box-shadow: 0 0 0 3px rgba(201, 169, 78, 0.2);
}

.test-answer-input.disabled {
  opacity: 0.6;
  background: var(--bg-input);
}

[data-theme="dark"] .test-answer-input {
  background: var(--bg-input);
  border-color: var(--border-color);
  color: var(--text-primary);
}

[data-theme="dark"] .test-answer-input:focus {
  border-color: var(--color-gold);
  box-shadow: 0 0 0 3px rgba(201, 169, 78, 0.15);
}

.test-submit-btn {
  align-self: stretch;
}

.test-answer-hint {
  font-size: var(--text-sm);
  color: var(--color-gold);
  font-weight: 600;
  margin-top: var(--space-2);
}

/* Test Passed Badge (inline) */
.test-passed-badge {
  display: inline-block;
  padding: 2px 8px;
  border-radius: var(--radius-full);
  background: var(--color-success);
  color: white;
  font-size: var(--text-xs);
  font-weight: 700;
  margin-left: var(--space-2);
  animation: fadeSlideIn var(--transition-normal) ease forwards;
}

/* Test Feedback Answers */
.test-feedback-answers {
  margin-bottom: var(--space-2);
}

.test-feedback-label {
  font-size: var(--text-xs);
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: 0.03em;
  color: var(--text-secondary);
  display: block;
  margin-bottom: var(--space-1);
}

.test-feedback-answer-list {
  list-style: none;
  padding: 0;
  margin: 0;
}

.test-feedback-answer-list li {
  font-size: var(--text-sm);
  color: var(--text-primary);
  padding: var(--space-1) 0;
  padding-left: var(--space-3);
  position: relative;
}

.test-feedback-answer-list li::before {
  content: '✓';
  position: absolute;
  left: 0;
  color: var(--color-success);
  font-weight: 700;
}

/* Test Score (progress bar area) */
.test-score {
  display: flex;
  align-items: center;
  gap: var(--space-1);
}

/* Test Result Hero */
.test-result-hero {
  position: relative;
  overflow: hidden;
}

.test-result-hero.test-passed {
  border: 2px solid var(--color-success);
}

.test-result-hero.test-failed {
  border: 2px solid var(--color-error);
}

[data-theme="dark"] .test-result-hero.test-passed {
  border-color: rgba(34, 197, 94, 0.5);
  background: rgba(34, 197, 94, 0.05);
}

[data-theme="dark"] .test-result-hero.test-failed {
  border-color: rgba(239, 68, 68, 0.5);
  background: rgba(239, 68, 68, 0.05);
}

.test-result-badge {
  font-size: 48px;
  margin-bottom: var(--space-2);
}

.test-result-verdict {
  font-size: var(--text-2xl);
  font-weight: 800;
  letter-spacing: -0.01em;
}

.test-result-verdict.pass {
  color: var(--color-success);
}

.test-result-verdict.fail {
  color: var(--color-error);
}

/* Question Breakdown */
.test-breakdown-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.test-breakdown-item {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  font-size: var(--text-sm);
  transition: background var(--transition-fast);
}

.test-breakdown-item.correct {
  background: rgba(34, 197, 94, 0.08);
}

.test-breakdown-item.wrong {
  background: rgba(239, 68, 68, 0.08);
}

.test-breakdown-num {
  font-weight: 700;
  font-size: var(--text-xs);
  color: var(--text-muted);
  min-width: 20px;
}

.test-breakdown-icon {
  font-weight: 700;
  font-size: var(--text-base);
}

.test-breakdown-item.correct .test-breakdown-icon {
  color: var(--color-success);
}

.test-breakdown-item.wrong .test-breakdown-icon {
  color: var(--color-error);
}

.test-breakdown-q {
  flex: 1;
  color: var(--text-secondary);
  line-height: 1.3;
}

/* Weak Categories */
.test-weak-category {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--border-color-light);
}

.test-weak-category:last-of-type {
  border-bottom: none;
}

.test-weak-icon {
  font-size: var(--text-lg);
  flex-shrink: 0;
}

.test-weak-name {
  flex: 1;
  font-weight: 600;
  color: var(--text-primary);
  font-size: var(--text-sm);
}

.test-weak-count {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--color-error);
  background: var(--color-error-light);
  padding: 2px 10px;
  border-radius: var(--radius-full);
}

[data-theme="dark"] .test-weak-count {
  background: rgba(239, 68, 68, 0.15);
  color: #FCA5A5;
}

/* Score Trend Chart */
.trend-chart-container {
  position: relative;
  height: 150px;
  padding-top: var(--space-4);
}

.trend-chart-pass-line {
  position: absolute;
  left: 0;
  right: 0;
  border-top: 2px dashed var(--color-success);
  opacity: 0.4;
  z-index: 1;
}

.trend-chart-pass-label {
  position: absolute;
  right: 0;
  top: -18px;
  font-size: var(--text-xs);
  color: var(--color-success);
  font-weight: 600;
}

.trend-chart-bars {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  gap: 6px;
  height: 100%;
  position: relative;
  z-index: 2;
}

.trend-bar-wrapper {
  display: flex;
  align-items: flex-end;
  justify-content: center;
  height: 100%;
}

.trend-bar {
  width: 100%;
  border-radius: 4px 4px 0 0;
  display: flex;
  align-items: flex-start;
  justify-content: center;
  min-height: 10%;
  transition: height var(--transition-normal);
}

.trend-bar.pass {
  background: var(--color-success);
}

.trend-bar.fail {
  background: var(--color-error);
}

.trend-bar-label {
  font-size: var(--text-xs);
  font-weight: 700;
  color: white;
  padding-top: 4px;
}

/* Confetti */
.confetti-container {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  pointer-events: none;
  z-index: 1000;
  overflow: hidden;
}

.confetti-piece {
  position: absolute;
  width: 8px;
  height: 14px;
  top: -20px;
  border-radius: 2px;
  animation: confettiFall linear forwards;
}

@keyframes confettiFall {
  0% {
    transform: translateY(0) rotate(0deg);
    opacity: 1;
  }
  100% {
    transform: translateY(100vh) rotate(720deg);
    opacity: 0;
  }
}

/* Test Question Card highlight */
.test-question-card {
  border-left: 4px solid var(--color-gold);
}

/* ========================================
   Responsive
   ======================================== */
@media (min-width: 640px) {
  #main-content {
    padding-bottom: var(--space-6);
    max-width: 640px;
    margin: 0 auto;
  }

  .app-header {
    border-radius: 0;
  }

  /* Desktop top nav instead of bottom nav */
  .bottom-nav {
    position: static;
    height: auto;
    box-shadow: none;
    border-top: none;
    border-bottom: 1px solid var(--border-color);
    max-width: 640px;
    margin: 0 auto;
    padding: var(--space-1) 0;
  }

  .nav-item {
    flex-direction: row;
    gap: var(--space-2);
    font-size: var(--text-sm);
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-md);
  }

  .nav-item .nav-icon {
    font-size: 18px;
  }

  .nav-item.active {
    background: var(--bg-input);
  }
}

@media (min-width: 768px) {
  .app-container {
    max-width: 720px;
  }

  .stat-grid {
    grid-template-columns: repeat(4, 1fr);
  }
}


/* ========================================
   Step 5: Visual Refinements
   ======================================== */

/* Header gradient */
.app-header {
  background: linear-gradient(135deg, var(--bg-header) 0%, var(--color-primary-light) 100%);
}

/* Card hover lift */
.card:hover,
.card-hover:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-2px);
  transition: all var(--transition-normal);
}

.card,
.card-hover {
  transition: box-shadow var(--transition-normal), transform var(--transition-normal);
}

/* Subtle body background pattern */
body {
  background: var(--bg-primary);
  background-image:
    radial-gradient(ellipse at 20% 50%, rgba(201, 169, 78, 0.03) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(27, 42, 74, 0.04) 0%, transparent 50%);
  background-attachment: fixed;
}

[data-theme="dark"] body {
  background-image:
    radial-gradient(ellipse at 20% 50%, rgba(201, 169, 78, 0.02) 0%, transparent 50%),
    radial-gradient(ellipse at 80% 20%, rgba(59, 130, 246, 0.02) 0%, transparent 50%);
}

/* Better button press animation */
.btn:active {
  transform: scale(0.95);
  transition: transform 80ms ease;
}

.btn-primary:active {
  background: var(--color-primary-dark);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.2);
}

.btn-gold:active {
  filter: brightness(0.9);
  box-shadow: inset 0 2px 4px rgba(0, 0, 0, 0.15);
}

/* Glass morphism card */
.card-glass {
  background: rgba(255, 255, 255, 0.6);
  backdrop-filter: blur(12px);
  -webkit-backdrop-filter: blur(12px);
  border: 1px solid rgba(255, 255, 255, 0.3);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.06);
}

[data-theme="dark"] .card-glass {
  background: rgba(30, 41, 59, 0.6);
  border: 1px solid rgba(255, 255, 255, 0.08);
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.3);
}


/* ========================================
   Progress Screen Styles
   ======================================== */

/* Mastery distribution bar */
.progress-mastery-bar {
  display: flex;
  height: 12px;
  border-radius: var(--radius-full);
  overflow: hidden;
  background: var(--bg-input);
  width: 100%;
}

.progress-mastery-bar .segment-not-seen {
  background: var(--color-error);
  transition: width var(--transition-slow);
}

.progress-mastery-bar .segment-seen {
  background: var(--color-warning);
  transition: width var(--transition-slow);
}

.progress-mastery-bar .segment-learned {
  background: var(--color-success);
  transition: width var(--transition-slow);
}

/* Category progress row */
.progress-category-row {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-3) 0;
  border-bottom: 1px solid var(--border-color-light);
}

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

.progress-category-row .category-name {
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
  min-width: 100px;
  flex-shrink: 0;
}

.progress-category-row .progress-bar {
  flex: 1;
  height: 6px;
}

.progress-category-row .category-count {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-muted);
  min-width: 40px;
  text-align: right;
  white-space: nowrap;
}

/* Milestone cards */
.milestone-card {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-4);
  border-radius: var(--radius-lg);
  background: var(--bg-card);
  border: 1px solid var(--border-color-light);
  transition: all var(--transition-normal);
}

.milestone-card + .milestone-card {
  margin-top: var(--space-2);
}

.milestone-card .milestone-icon {
  font-size: 28px;
  flex-shrink: 0;
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  border-radius: var(--radius-md);
  background: var(--bg-input);
}

.milestone-card .milestone-info {
  flex: 1;
  min-width: 0;
}

.milestone-card .milestone-name {
  font-size: var(--text-sm);
  font-weight: 700;
  color: var(--text-primary);
}

.milestone-card .milestone-desc {
  font-size: var(--text-xs);
  color: var(--text-secondary);
  margin-top: 2px;
}

/* Earned milestone — gold glow */
.milestone-card.earned {
  border-color: var(--color-gold);
  box-shadow: 0 0 12px rgba(201, 169, 78, 0.2), var(--shadow-card);
}

.milestone-card.earned .milestone-icon {
  background: rgba(201, 169, 78, 0.15);
}

[data-theme="dark"] .milestone-card.earned {
  border-color: var(--color-gold);
  box-shadow: 0 0 16px rgba(201, 169, 78, 0.15);
}

/* Locked milestone — greyed out */
.milestone-card.locked {
  opacity: 0.5;
  filter: grayscale(0.6);
}

.milestone-card.locked .milestone-icon {
  filter: grayscale(1);
}

/* Activity feed */
.activity-feed {
  display: flex;
  flex-direction: column;
  position: relative;
  padding-left: var(--space-5);
}

.activity-feed::before {
  content: '';
  position: absolute;
  left: 9px;
  top: 4px;
  bottom: 4px;
  width: 2px;
  background: var(--border-color);
  border-radius: 1px;
}

.activity-item {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  position: relative;
}

.activity-item::before {
  content: '';
  position: absolute;
  left: calc(-1 * var(--space-5) + 5px);
  top: calc(var(--space-2) + 6px);
  width: 10px;
  height: 10px;
  border-radius: 50%;
  background: var(--color-gold);
  border: 2px solid var(--bg-primary);
  z-index: 1;
}

.activity-item .activity-icon {
  font-size: var(--text-base);
  flex-shrink: 0;
}

.activity-item .activity-text {
  flex: 1;
  font-size: var(--text-sm);
  color: var(--text-primary);
  line-height: 1.4;
}

.activity-item .activity-time {
  font-size: var(--text-xs);
  color: var(--text-muted);
  white-space: nowrap;
  flex-shrink: 0;
}

/* Reset progress danger button */
.reset-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  padding: var(--space-3) var(--space-5);
  border-radius: var(--radius-md);
  font-family: var(--font-sans);
  font-size: var(--text-sm);
  font-weight: 600;
  border: 2px solid var(--color-error);
  background: transparent;
  color: var(--color-error);
  cursor: pointer;
  transition: all var(--transition-fast);
  min-height: 44px;
}

.reset-btn:hover {
  background: var(--color-error);
  color: white;
}

.reset-btn:active {
  transform: scale(0.95);
  background: #DC2626;
  color: white;
}

[data-theme="dark"] .reset-btn {
  border-color: #FCA5A5;
  color: #FCA5A5;
}

[data-theme="dark"] .reset-btn:hover {
  background: var(--color-error);
  border-color: var(--color-error);
  color: white;
}


/* ========================================
   Enhanced Animations
   ======================================== */

/* Generic fade + slide entrance */
.animate-in {
  animation: animateIn var(--transition-normal) ease forwards;
  opacity: 0;
}

@keyframes animateIn {
  from {
    opacity: 0;
    transform: translateY(12px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Scale up entrance */
.animate-scale {
  animation: animateScale var(--transition-normal) ease forwards;
  opacity: 0;
}

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

/* Staggered delays */
.stagger-1 { animation-delay: 60ms; }
.stagger-2 { animation-delay: 120ms; }
.stagger-3 { animation-delay: 180ms; }

/* Improved page transitions */
.page-exit {
  opacity: 0;
  transform: translateY(6px);
  transition: opacity 180ms ease, transform 180ms ease;
}

.page-enter {
  animation: pageEnterSmooth 280ms cubic-bezier(0.22, 1, 0.36, 1) forwards;
}

@keyframes pageEnterSmooth {
  from {
    opacity: 0;
    transform: translateY(10px);
  }
  to {
    opacity: 1;
    transform: translateY(0);
  }
}

/* Card hover lift class */
.card-hover {
  cursor: pointer;
}

.card-hover:hover {
  box-shadow: var(--shadow-lg);
  transform: translateY(-3px);
}

.card-hover:active {
  transform: translateY(0);
  box-shadow: var(--shadow-sm);
  transition: all 80ms ease;
}


/* ========================================
   Dark Mode Refinements
   ======================================== */

/* Active card border glow in dark mode */
[data-theme="dark"] .card:focus-within,
[data-theme="dark"] .card.active {
  box-shadow: 0 0 0 1px rgba(201, 169, 78, 0.3), var(--shadow-card);
}

[data-theme="dark"] .action-card:hover {
  box-shadow: 0 0 0 1px rgba(201, 169, 78, 0.2), var(--shadow-md);
}

/* Muted badge colors in dark mode */
[data-theme="dark"] .badge-gold {
  background: rgba(201, 169, 78, 0.1);
  color: #D4B85C;
}

[data-theme="dark"] .badge-success {
  background: rgba(34, 197, 94, 0.1);
  color: #6EE7A0;
}

[data-theme="dark"] .badge-error {
  background: rgba(239, 68, 68, 0.1);
  color: #FCA5A5;
}


/* ========================================
   Better Bottom Nav
   ======================================== */

/* Active indicator line */
.nav-item {
  position: relative;
}

.nav-item.active::before {
  content: '';
  position: absolute;
  top: -1px;
  left: 50%;
  transform: translateX(-50%);
  width: 24px;
  height: 2px;
  background: var(--color-gold);
  border-radius: 1px;
}

/* Stronger active contrast */
.nav-item.active {
  color: var(--color-primary);
  font-weight: 600;
}

[data-theme="dark"] .nav-item.active {
  color: var(--color-gold);
}

/* iPhone safe area */
.bottom-nav {
  padding-bottom: env(safe-area-inset-bottom, 0px);
  height: calc(var(--nav-height) + env(safe-area-inset-bottom, 0px));
}

/* Adjust main content bottom padding for safe area */
#main-content {
  padding-bottom: calc(var(--nav-height) + env(safe-area-inset-bottom, 0px) + var(--space-4));
}

/* Desktop override — no active indicator line on top nav */
@media (min-width: 640px) {
  .nav-item.active::before {
    display: none;
  }

  .bottom-nav {
    padding-bottom: 0;
    height: auto;
  }

  #main-content {
    padding-bottom: var(--space-6);
  }
}


/* ========================================
   Typography Improvements
   ======================================== */

/* Gold gradient text */
.text-gradient {
  background: linear-gradient(135deg, var(--color-gold) 0%, var(--color-gold-light) 50%, var(--color-gold) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

[data-theme="dark"] .text-gradient {
  background: linear-gradient(135deg, var(--color-gold-light) 0%, var(--color-gold) 50%, var(--color-gold-light) 100%);
  -webkit-background-clip: text;
  -webkit-text-fill-color: transparent;
  background-clip: text;
}

/* Section header with bottom border accent */
.section-header {
  font-size: var(--text-lg);
  font-weight: 700;
  color: var(--text-primary);
  padding-bottom: var(--space-3);
  margin-bottom: var(--space-4);
  border-bottom: 2px solid var(--border-color);
  position: relative;
}

.section-header::after {
  content: '';
  position: absolute;
  bottom: -2px;
  left: 0;
  width: 40px;
  height: 2px;
  background: var(--color-gold);
  border-radius: 1px;
}

/* ========================================
   Progress Screen (Step 5 Full Build)
   ======================================== */

/* Mastery Distribution Bar */
.prog-dist-bar {
  display: flex;
  height: 12px;
  border-radius: var(--radius-full);
  overflow: hidden;
  background: var(--bg-input);
  margin-top: var(--space-3);
}

.prog-dist-segment {
  transition: width var(--transition-slow);
  min-width: 0;
}

.prog-dist-learned { background: var(--color-success); }
.prog-dist-seen { background: var(--color-warning); }
.prog-dist-new { background: var(--bg-input); }

.prog-dist-legend {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-4);
  margin-top: var(--space-2);
  font-size: var(--text-xs);
  color: var(--text-muted);
}

/* Category / Subcategory Progress Rows */
.prog-cat-row {
  margin-bottom: var(--space-3);
}

.prog-cat-row:last-child {
  margin-bottom: 0;
}

.prog-cat-header {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-1);
}

.prog-cat-icon {
  font-size: 20px;
  flex-shrink: 0;
}

.prog-cat-name {
  flex: 1;
  font-size: var(--text-sm);
  font-weight: 600;
  color: var(--text-primary);
}

.prog-cat-count {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--text-muted);
  white-space: nowrap;
}

.prog-sub-row {
  padding-left: var(--space-2);
  margin-bottom: var(--space-2);
}

.prog-sub-row .prog-cat-name {
  font-size: var(--text-xs);
}

/* Recent Results List */
.prog-recent-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.prog-recent-item {
  display: flex;
  align-items: center;
  gap: var(--space-3);
  padding: var(--space-2) 0;
  border-bottom: 1px solid var(--border-color-light);
}

.prog-recent-item:last-child {
  border-bottom: none;
}

/* Milestones Grid */
.prog-milestones-grid {
  display: grid;
  grid-template-columns: repeat(2, 1fr);
  gap: var(--space-2);
}

.prog-milestone-item {
  display: flex;
  flex-direction: column;
  align-items: center;
  text-align: center;
  padding: var(--space-3);
  border-radius: var(--radius-md);
  background: var(--bg-input);
  border: 1px solid var(--border-color-light);
  transition: all var(--transition-fast);
}

.prog-milestone-item.earned {
  background: rgba(201, 169, 78, 0.1);
  border-color: var(--color-gold);
}

.prog-milestone-item.locked {
  opacity: 0.4;
}

.prog-milestone-icon {
  font-size: 24px;
  margin-bottom: var(--space-1);
}

.prog-milestone-name {
  font-size: var(--text-xs);
  font-weight: 700;
  color: var(--text-primary);
}

.prog-milestone-desc {
  font-size: 10px;
  color: var(--text-muted);
  margin-top: 2px;
}

/* Milestone Badge Row (Home Dashboard) */
.prog-milestone-row {
  display: flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-3);
}

.prog-milestone-badge {
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 2px;
  transition: all var(--transition-fast);
}

.prog-milestone-badge.earned .prog-milestone-icon {
  font-size: 28px;
}

.prog-milestone-badge.locked {
  opacity: 0.3;
  filter: grayscale(1);
}

.prog-milestone-badge.locked .prog-milestone-icon {
  font-size: 28px;
}

.prog-milestone-badge .prog-milestone-label {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--text-muted);
}

/* Continue Studying Suggestion Card */
.prog-suggestion-card {
  cursor: pointer;
  transition: all var(--transition-fast);
}

.prog-suggestion-card:hover {
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

/* Reset Confirmation Overlay */
.prog-confirm-overlay {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  bottom: 0;
  background: rgba(0, 0, 0, 0.5);
  display: flex;
  align-items: center;
  justify-content: center;
  z-index: 1000;
  padding: var(--space-4);
  animation: fadeSlideIn var(--transition-fast) ease forwards;
}

[data-theme="dark"] .prog-confirm-overlay {
  background: rgba(0, 0, 0, 0.7);
}

.prog-confirm-dialog {
  background: var(--bg-card);
  border-radius: var(--radius-xl);
  padding: var(--space-6);
  max-width: 360px;
  width: 100%;
  text-align: center;
  box-shadow: var(--shadow-lg);
}

/* Milestone Toast Notification */
.prog-toast {
  position: fixed;
  top: calc(var(--header-height) + var(--space-3));
  left: 50%;
  transform: translateX(-50%) translateY(-20px);
  background: var(--bg-card);
  border: 2px solid var(--color-gold);
  border-radius: var(--radius-lg);
  padding: var(--space-3) var(--space-5);
  box-shadow: 0 8px 32px rgba(201, 169, 78, 0.25), var(--shadow-lg);
  display: flex;
  align-items: center;
  gap: var(--space-3);
  z-index: 1100;
  opacity: 0;
  transition: opacity 0.3s ease, transform 0.3s ease;
  pointer-events: none;
  max-width: calc(var(--max-width) - var(--space-8));
}

.prog-toast.show {
  opacity: 1;
  transform: translateX(-50%) translateY(0);
}

.prog-toast-icon {
  font-size: 32px;
  flex-shrink: 0;
}

.prog-toast-title {
  font-size: var(--text-xs);
  font-weight: 600;
  color: var(--color-gold);
  text-transform: uppercase;
  letter-spacing: 0.03em;
}

.prog-toast-name {
  font-size: var(--text-base);
  font-weight: 700;
  color: var(--text-primary);
}

[data-theme="dark"] .prog-toast {
  background: var(--bg-secondary);
  box-shadow: 0 8px 32px rgba(201, 169, 78, 0.15), 0 4px 12px rgba(0, 0, 0, 0.4);
}

/* ========================================
   Accessibility — Screen Reader Only
   ======================================== */
.sr-only {
  position: absolute;
  width: 1px;
  height: 1px;
  padding: 0;
  margin: -1px;
  overflow: hidden;
  clip: rect(0, 0, 0, 0);
  white-space: nowrap;
  border-width: 0;
}

/* Focus Indicators */
:focus-visible {
  outline: 3px solid var(--color-gold);
  outline-offset: 2px;
  border-radius: var(--radius-sm);
}

button:focus-visible,
a:focus-visible,
input:focus-visible,
[tabindex]:focus-visible {
  outline: 3px solid var(--color-gold);
  outline-offset: 2px;
}

/* Reduce motion */
.reduce-motion *,
.reduce-motion *::before,
.reduce-motion *::after {
  animation-duration: 0.01ms !important;
  animation-iteration-count: 1 !important;
  transition-duration: 0.01ms !important;
}

@media (prefers-reduced-motion: reduce) {
  *,
  *::before,
  *::after {
    animation-duration: 0.01ms !important;
    animation-iteration-count: 1 !important;
    transition-duration: 0.01ms !important;
    scroll-behavior: auto !important;
  }
}

/* ========================================
   Speak (Audio) Button
   ======================================== */
.speak-btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  width: 36px;
  height: 36px;
  border: none;
  border-radius: 50%;
  background: rgba(201, 169, 78, 0.12);
  color: var(--color-gold);
  cursor: pointer;
  transition: background-color 0.2s, transform 0.1s;
  flex-shrink: 0;
  padding: 0;
}

.speak-btn:hover {
  background: rgba(201, 169, 78, 0.25);
}

.speak-btn:active {
  transform: scale(0.92);
}

.speak-btn.speaking {
  background: var(--color-gold);
  color: var(--text-on-gold);
  animation: speak-pulse 1s ease-in-out infinite;
}

@keyframes speak-pulse {
  0%, 100% { opacity: 1; }
  50% { opacity: 0.7; }
}

.speak-btn-icon {
  font-size: 16px;
  line-height: 1;
}

/* Flashcard header row for Q number + speak button */
.flashcard-header-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
}

.flashcard-header-row .speak-btn {
  position: relative;
  z-index: 2;
}

/* Prevent speak button clicks from flipping the card */
.flashcard-header-row .speak-btn {
  pointer-events: auto;
}

/* Dark mode speak button */
[data-theme="dark"] .speak-btn {
  background: rgba(201, 169, 78, 0.15);
}

[data-theme="dark"] .speak-btn:hover {
  background: rgba(201, 169, 78, 0.3);
}

[data-theme="dark"] .speak-btn.speaking {
  background: var(--color-gold);
  color: var(--color-primary-dark);
}

/* ========================================
   Settings Page
   ======================================== */
.settings-options {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-2);
  margin-top: var(--space-2);
}

.settings-toggle-row {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: var(--space-2) 0;
  font-weight: 500;
}

.settings-toggle {
  position: relative;
  width: 52px;
  height: 28px;
  border: none;
  border-radius: 14px;
  background: var(--bg-input);
  cursor: pointer;
  transition: background-color 0.25s;
  padding: 0;
}

.settings-toggle.active {
  background: var(--color-gold);
}

.settings-toggle-knob {
  position: absolute;
  top: 3px;
  left: 3px;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  background: white;
  box-shadow: 0 1px 3px rgba(0, 0, 0, 0.2);
  transition: transform 0.25s;
}

.settings-toggle.active .settings-toggle-knob {
  transform: translateX(24px);
}

.settings-subsection {
  margin-top: var(--space-3);
  padding-top: var(--space-3);
  border-top: 1px solid var(--border-color);
}

/* Dark mode settings */
[data-theme="dark"] .settings-toggle {
  background: var(--bg-input);
}

[data-theme="dark"] .settings-toggle.active {
  background: var(--color-gold);
}

[data-theme="dark"] .settings-toggle-knob {
  background: var(--bg-secondary);
}

/* ========================================
   WCAG Color Contrast Fixes
   ======================================== */
/* Ensure muted text meets WCAG AA (4.5:1) */
.text-muted {
  color: #64748B; /* 4.7:1 on white */
}

[data-theme="dark"] .text-muted {
  color: #94A3B8; /* 4.6:1 on dark bg */
}

/* Quiz option hover/focus states */
.quiz-option:focus-visible {
  outline: 3px solid var(--color-gold);
  outline-offset: 2px;
}

/* Nav item focus */
.nav-item:focus-visible {
  outline: 3px solid var(--color-gold);
  outline-offset: -2px;
}

/* Skip to main content link (hidden until focused) */
.skip-link {
  position: absolute;
  top: -100%;
  left: 50%;
  transform: translateX(-50%);
  background: var(--color-gold);
  color: var(--text-on-gold);
  padding: var(--space-2) var(--space-4);
  border-radius: var(--radius-md);
  font-weight: 600;
  z-index: 9999;
  text-decoration: none;
  transition: top 0.2s;
}

.skip-link:focus {
  top: var(--space-2);
}