:root {
  --bg: #f4f7fb;
  --bg-elevated: #ffffff;
  --surface: rgba(255, 255, 255, 0.72);
  --surface-solid: #ffffff;
  --surface2: #f8fafc;
  --border: rgba(15, 23, 42, 0.08);
  --border-strong: rgba(15, 23, 42, 0.12);
  --accent: #0d9488;
  --accent-light: #14b8a6;
  --accent-glow: rgba(13, 148, 136, 0.25);
  --accent2: #6366f1;
  --accent3: #e11d48;
  --accent4: #7c3aed;
  --warn: #d97706;
  --text: #0f172a;
  --text2: #475569;
  --text3: #94a3b8;
  --correct: #047857;
  --correct-bg: #ecfdf5;
  --correct-border: #10b981;
  --wrong-border: #f43f5e;
  --wrong-bg: #fff1f2;
  --shadow-sm: 0 1px 2px rgba(15, 23, 42, 0.04);
  --shadow-md: 0 8px 30px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.12);
  --shadow-card: 0 4px 24px rgba(15, 23, 42, 0.06), 0 1px 3px rgba(15, 23, 42, 0.04);
  --radius: 16px;
  --radius-lg: 24px;
  --transition: 0.25s cubic-bezier(0.4, 0, 0.2, 1);
  --font: 'DM Sans', system-ui, sans-serif;
  --font-display: 'Instrument Serif', Georgia, serif;
}

* {
  margin: 0;
  padding: 0;
  box-sizing: border-box;
}

html {
  scroll-behavior: smooth;
}

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  min-height: 100vh;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

/* ── BACKGROUND ── */
.bg-mesh {
  position: fixed;
  inset: 0;
  z-index: 0;
  pointer-events: none;
  background:
    radial-gradient(ellipse 80% 60% at 0% 0%, rgba(13, 148, 136, 0.12) 0%, transparent 55%),
    radial-gradient(ellipse 70% 50% at 100% 20%, rgba(99, 102, 241, 0.1) 0%, transparent 50%),
    radial-gradient(ellipse 60% 40% at 50% 100%, rgba(124, 58, 237, 0.06) 0%, transparent 55%),
    linear-gradient(180deg, #f8fafc 0%, var(--bg) 40%, #eef2f7 100%);
}

.bg-mesh::before {
  content: '';
  position: absolute;
  inset: 0;
  background-image: radial-gradient(rgba(15, 23, 42, 0.04) 1px, transparent 1px);
  background-size: 28px 28px;
  mask-image: radial-gradient(ellipse 80% 70% at 50% 30%, black 20%, transparent 75%);
}

.bg-orb {
  position: fixed;
  border-radius: 50%;
  filter: blur(80px);
  pointer-events: none;
  z-index: 0;
  animation: floatOrb 18s ease-in-out infinite;
}

.bg-orb-1 {
  width: 420px;
  height: 420px;
  top: -120px;
  left: -80px;
  background: rgba(13, 148, 136, 0.2);
}

.bg-orb-2 {
  width: 360px;
  height: 360px;
  bottom: -100px;
  right: -60px;
  background: rgba(99, 102, 241, 0.15);
  animation-delay: -6s;
}

@keyframes floatOrb {
  0%, 100% { transform: translate(0, 0) scale(1); }
  50% { transform: translate(24px, -20px) scale(1.05); }
}

#app {
  position: relative;
  z-index: 1;
}

/* ════════════ HOME ════════════ */
#home {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  padding: 56px 24px 80px;
  gap: 48px;
}

.hero {
  text-align: center;
  max-width: 720px;
  animation: fadeUp 0.7s ease both;
}

.hero-icon {
  width: 64px;
  height: 64px;
  margin: 0 auto 24px;
  border-radius: 20px;
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent2) 100%);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 28px;
  box-shadow: 0 12px 32px var(--accent-glow);
}

.badge {
  display: inline-flex;
  align-items: center;
  gap: 8px;
  font-size: 11px;
  font-weight: 700;
  letter-spacing: 0.12em;
  text-transform: uppercase;
  color: var(--accent);
  background: rgba(13, 148, 136, 0.08);
  border: 1px solid rgba(13, 148, 136, 0.2);
  padding: 6px 16px;
  border-radius: 99px;
  margin-bottom: 20px;
}

.hero h1 {
  font-family: var(--font-display);
  font-size: clamp(2.75rem, 7vw, 4.5rem);
  font-weight: 400;
  line-height: 1.08;
  letter-spacing: -0.02em;
  margin-bottom: 20px;
  color: var(--text);
}

.hero h1 em {
  font-style: italic;
  background: linear-gradient(120deg, var(--accent) 0%, var(--accent2) 55%, var(--accent4) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.hero p {
  font-size: 1.125rem;
  color: var(--text2);
  line-height: 1.75;
  max-width: 520px;
  margin: 0 auto;
  font-weight: 400;
}

.stats-row {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
  margin-top: 32px;
}

.stat-pill {
  display: flex;
  align-items: center;
  gap: 10px;
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: 99px;
  padding: 10px 20px;
  font-size: 13px;
  font-weight: 600;
  color: var(--text2);
  box-shadow: var(--shadow-sm);
  transition: var(--transition);
}

.stat-pill:hover {
  border-color: var(--border-strong);
  box-shadow: var(--shadow-md);
  transform: translateY(-1px);
}

.stat-pill .dot {
  width: 8px;
  height: 8px;
  border-radius: 50%;
  background: var(--accent);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.2);
  flex-shrink: 0;
}

.stat-pill:nth-child(2) .dot {
  background: var(--accent2);
  box-shadow: 0 0 0 3px rgba(99, 102, 241, 0.2);
}

.stat-pill:nth-child(3) .dot {
  background: var(--accent4);
  box-shadow: 0 0 0 3px rgba(124, 58, 237, 0.2);
}

.home-content {
  max-width: 1080px;
  width: 100%;
  display: flex;
  flex-direction: column;
  gap: 24px;
  align-items: center;
  animation: fadeUp 0.7s 0.15s ease both;
}

/* ── CHAPTERS GRID ── */
.chapters-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(300px, 1fr));
  gap: 18px;
  width: 100%;
}

.chapter-card {
  --card-accent: var(--accent);
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 24px;
  cursor: pointer;
  transition: var(--transition);
  position: relative;
  overflow: hidden;
  box-shadow: var(--shadow-card);
  animation: fadeUp 0.5s ease both;
}

.chapter-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 3px;
  background: linear-gradient(90deg, var(--card-accent), color-mix(in srgb, var(--card-accent) 60%, white));
  opacity: 0.9;
}

.chapter-card::after {
  content: '';
  position: absolute;
  inset: 0;
  background: linear-gradient(135deg, color-mix(in srgb, var(--card-accent) 6%, transparent) 0%, transparent 50%);
  pointer-events: none;
  opacity: 0;
  transition: opacity var(--transition);
}

.chapter-card:nth-child(1) { animation-delay: 0.05s; }
.chapter-card:nth-child(2) { animation-delay: 0.1s; }
.chapter-card:nth-child(3) { animation-delay: 0.15s; }
.chapter-card:nth-child(4) { animation-delay: 0.2s; }
.chapter-card:nth-child(5) { animation-delay: 0.25s; }
.chapter-card:nth-child(6) { animation-delay: 0.3s; }
.chapter-card:nth-child(n+7) { animation-delay: 0.35s; }

@keyframes fadeUp {
  from {
    opacity: 0;
    transform: translateY(20px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.chapter-card:hover {
  border-color: color-mix(in srgb, var(--card-accent) 35%, var(--border));
  transform: translateY(-4px);
  box-shadow: var(--shadow-lg);
}

.chapter-card:hover::after {
  opacity: 1;
}

.ch-header {
  display: flex;
  align-items: flex-start;
  gap: 14px;
  margin-bottom: 12px;
  position: relative;
  z-index: 1;
}

.ch-num {
  width: 42px;
  height: 42px;
  border-radius: 12px;
  flex-shrink: 0;
  background: color-mix(in srgb, var(--card-accent) 12%, white);
  border: 1px solid color-mix(in srgb, var(--card-accent) 25%, transparent);
  display: flex;
  align-items: center;
  justify-content: center;
  font-family: var(--font-display);
  font-size: 1.15rem;
  font-weight: 400;
  color: var(--card-accent);
}

.ch-title {
  font-size: 1rem;
  font-weight: 700;
  line-height: 1.4;
  color: var(--text);
  padding-top: 2px;
}

.ch-desc {
  font-size: 13px;
  color: var(--text2);
  line-height: 1.6;
  margin-bottom: 18px;
  position: relative;
  z-index: 1;
}

.ch-footer {
  display: flex;
  align-items: center;
  justify-content: space-between;
  position: relative;
  z-index: 1;
}

.ch-count {
  font-size: 12px;
  font-weight: 600;
  color: var(--text3);
  background: var(--surface2);
  padding: 4px 10px;
  border-radius: 6px;
}

.btn-go {
  background: var(--card-accent);
  color: #fff;
  border: none;
  border-radius: 10px;
  padding: 8px 16px;
  font-family: var(--font);
  font-size: 13px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
  box-shadow: 0 4px 14px color-mix(in srgb, var(--card-accent) 35%, transparent);
}

.btn-go:hover {
  filter: brightness(1.08);
  transform: translateX(2px);
  box-shadow: 0 6px 20px color-mix(in srgb, var(--card-accent) 45%, transparent);
}

.btn-all {
  background: linear-gradient(135deg, var(--accent) 0%, var(--accent2) 100%);
  border: none;
  color: #fff;
  border-radius: 14px;
  padding: 16px 32px;
  font-family: var(--font);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 10px;
  box-shadow: 0 8px 28px rgba(13, 148, 136, 0.35);
  letter-spacing: -0.01em;
}

.btn-all:hover {
  transform: translateY(-2px);
  box-shadow: 0 12px 36px rgba(13, 148, 136, 0.4);
  filter: brightness(1.05);
}

.btn-all:active {
  transform: translateY(0);
}

/* ════════════ QUIZ ════════════ */
#quiz {
  display: none;
  min-height: 100vh;
}

.quiz-topbar {
  position: sticky;
  top: 0;
  z-index: 100;
  background: rgba(244, 247, 251, 0.85);
  backdrop-filter: blur(20px) saturate(1.2);
  -webkit-backdrop-filter: blur(20px) saturate(1.2);
  border-bottom: 1px solid var(--border);
  padding: 14px 24px;
  display: flex;
  align-items: center;
  gap: 16px;
}

.btn-back {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  color: var(--text2);
  border-radius: 10px;
  padding: 8px 14px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 6px;
  font-family: var(--font);
  transition: var(--transition);
  flex-shrink: 0;
  box-shadow: var(--shadow-sm);
}

.btn-back:hover {
  color: var(--accent);
  border-color: rgba(13, 148, 136, 0.35);
  background: #fff;
}

.quiz-title-bar {
  font-size: 13px;
  font-weight: 700;
  color: var(--text2);
  white-space: nowrap;
  overflow: hidden;
  text-overflow: ellipsis;
  max-width: 180px;
}

.progress-wrap {
  flex: 1;
  display: flex;
  flex-direction: column;
  gap: 6px;
}

.progress-info {
  display: flex;
  justify-content: space-between;
  font-size: 12px;
  font-weight: 600;
  color: var(--text3);
}

.progress-bar-track {
  height: 6px;
  background: rgba(15, 23, 42, 0.06);
  border-radius: 99px;
  overflow: hidden;
}

.progress-bar-fill {
  height: 100%;
  border-radius: 99px;
  background: linear-gradient(90deg, var(--accent), var(--accent2));
  transition: width 0.5s cubic-bezier(0.4, 0, 0.2, 1);
  box-shadow: 0 0 12px var(--accent-glow);
}

.score-badge {
  flex-shrink: 0;
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 700;
  white-space: nowrap;
  box-shadow: var(--shadow-sm);
}

.s-right {
  color: var(--correct);
}

.s-wrong {
  color: var(--accent3);
}

.mode-row {
  display: flex;
  gap: 8px;
  padding: 16px 24px 0;
  max-width: 800px;
  margin: 0 auto;
  flex-wrap: wrap;
}

.mode-btn {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  color: var(--text2);
  border-radius: 10px;
  padding: 8px 16px;
  font-size: 13px;
  font-weight: 600;
  cursor: pointer;
  font-family: var(--font);
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 6px;
  box-shadow: var(--shadow-sm);
}

.mode-btn.active {
  background: rgba(13, 148, 136, 0.1);
  border-color: var(--accent);
  color: var(--accent);
  box-shadow: 0 0 0 3px rgba(13, 148, 136, 0.12);
}

.mode-btn:hover:not(.active) {
  border-color: var(--border-strong);
  color: var(--text);
  background: #fff;
}

.quiz-body {
  max-width: 800px;
  margin: 0 auto;
  padding: 28px 24px 100px;
}

.question-meta {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 16px;
}

.q-type-badge {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  padding: 5px 12px;
  border-radius: 8px;
}

.q-type-badge.choix_multiple {
  background: rgba(99, 102, 241, 0.12);
  color: var(--accent2);
}

.q-type-badge.vrai_faux {
  background: rgba(217, 119, 6, 0.12);
  color: var(--warn);
}

.q-type-badge.piege {
  background: rgba(225, 29, 72, 0.1);
  color: var(--accent3);
}

.q-type-badge.definition {
  background: rgba(124, 58, 237, 0.12);
  color: var(--accent4);
}

.q-type-badge.cas_pratique {
  background: rgba(13, 148, 136, 0.12);
  color: var(--accent);
}

.q-number {
  font-size: 13px;
  font-weight: 700;
  color: var(--text3);
  margin-left: auto;
  font-variant-numeric: tabular-nums;
}

.question-card {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: 32px;
  margin-bottom: 20px;
  box-shadow: var(--shadow-md);
  animation: slideIn 0.35s ease both;
}

@keyframes slideIn {
  from {
    opacity: 0;
    transform: translateY(16px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.question-text {
  font-family: var(--font-display);
  font-size: 1.45rem;
  font-weight: 400;
  line-height: 1.5;
  color: var(--text);
  letter-spacing: -0.01em;
}

.question-hint {
  margin-top: 14px;
  font-size: 13px;
  color: var(--warn);
  font-weight: 500;
  padding: 10px 14px;
  background: rgba(217, 119, 6, 0.08);
  border-radius: 10px;
  border-left: 3px solid var(--warn);
}

.options-list {
  display: flex;
  flex-direction: column;
  gap: 12px;
  margin-top: 28px;
}

.option-btn {
  background: var(--surface2);
  border: 2px solid transparent;
  outline: 1px solid var(--border);
  color: var(--text);
  border-radius: 14px;
  padding: 16px 18px;
  text-align: left;
  font-family: var(--font);
  font-size: 15px;
  font-weight: 500;
  cursor: pointer;
  transition: var(--transition);
  display: flex;
  align-items: flex-start;
  gap: 14px;
  line-height: 1.55;
}

.option-letter {
  flex-shrink: 0;
  width: 32px;
  height: 32px;
  border-radius: 10px;
  background: #fff;
  border: 1px solid var(--border);
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 12px;
  font-weight: 800;
  color: var(--text2);
  transition: var(--transition);
}

.option-btn:hover:not(:disabled) {
  outline-color: var(--accent);
  background: #fff;
  transform: translateX(4px);
  box-shadow: var(--shadow-md);
}

.option-btn:hover:not(:disabled) .option-letter {
  background: var(--accent);
  border-color: var(--accent);
  color: #fff;
}

.option-btn.correct {
  outline-color: var(--correct-border);
  background: var(--correct-bg);
  color: var(--correct);
}

.option-btn.correct .option-letter {
  background: var(--correct-border);
  border-color: var(--correct-border);
  color: #fff;
}

.option-btn.selected-wrong {
  outline-color: var(--wrong-border);
  background: var(--wrong-bg);
  color: #be123c;
  animation: shake 0.38s ease;
}

.option-btn.wrong {
  outline-color: var(--wrong-border);
  background: var(--wrong-bg);
}

.option-btn.wrong .option-letter {
  background: var(--wrong-border);
  border-color: var(--wrong-border);
  color: #fff;
}

.option-btn:disabled {
  cursor: default;
  transform: none !important;
}

@keyframes shake {
  0%, 100% { transform: translateX(0); }
  25% { transform: translateX(-5px); }
  75% { transform: translateX(5px); }
}

.explanation-card {
  border-radius: var(--radius-lg);
  padding: 24px;
  margin-top: 20px;
  animation: expandIn 0.35s ease both;
  border: 1px solid;
  box-shadow: var(--shadow-sm);
}

@keyframes expandIn {
  from {
    opacity: 0;
    transform: translateY(8px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.explanation-card.correct-card {
  background: var(--correct-bg);
  border-color: rgba(16, 185, 129, 0.35);
}

.explanation-card.wrong-card {
  background: var(--wrong-bg);
  border-color: rgba(244, 63, 94, 0.35);
}

.expl-header {
  display: flex;
  align-items: center;
  gap: 12px;
  margin-bottom: 14px;
}

.expl-icon {
  width: 36px;
  height: 36px;
  border-radius: 50%;
  display: flex;
  align-items: center;
  justify-content: center;
  font-size: 16px;
  font-weight: 800;
  flex-shrink: 0;
}

.correct-card .expl-icon {
  background: rgba(16, 185, 129, 0.2);
  color: var(--correct);
}

.wrong-card .expl-icon {
  background: rgba(244, 63, 94, 0.15);
  color: var(--accent3);
}

.expl-verdict {
  font-weight: 800;
  font-size: 16px;
  letter-spacing: -0.02em;
}

.correct-card .expl-verdict {
  color: var(--correct);
}

.wrong-card .expl-verdict {
  color: #be123c;
}

.expl-section {
  margin-top: 14px;
}

.expl-label {
  font-size: 10px;
  font-weight: 800;
  letter-spacing: 0.1em;
  text-transform: uppercase;
  color: var(--text3);
  margin-bottom: 6px;
}

.expl-text {
  font-size: 14px;
  color: var(--text2);
  line-height: 1.7;
}

.expl-course {
  margin-top: 14px;
  background: rgba(255, 255, 255, 0.7);
  border: 1px solid var(--border);
  border-radius: 12px;
  padding: 14px 16px;
}

.wrong-options {
  margin-top: 14px;
}

.wrong-item {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  padding: 8px 0;
  border-top: 1px solid var(--border);
  font-size: 13px;
  color: var(--text2);
}

.wrong-item:first-child {
  border-top: none;
}

.wrong-label {
  flex-shrink: 0;
  font-weight: 800;
  color: var(--accent3);
  font-size: 12px;
}

.nav-row {
  display: flex;
  justify-content: flex-end;
  margin-top: 24px;
}

.btn-next {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  border: none;
  color: #fff;
  border-radius: 14px;
  padding: 14px 28px;
  font-family: var(--font);
  font-size: 15px;
  font-weight: 700;
  cursor: pointer;
  display: flex;
  align-items: center;
  gap: 8px;
  transition: var(--transition);
  box-shadow: 0 6px 20px var(--accent-glow);
}

.btn-next:hover:not(:disabled) {
  transform: translateX(4px);
  box-shadow: 0 10px 28px var(--accent-glow);
}

.btn-next:disabled {
  opacity: 0.4;
  cursor: default;
  transform: none;
  box-shadow: none;
}

/* ════════════ RESULTS ════════════ */
#results {
  display: none;
}

.results-wrapper {
  min-height: 100vh;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  padding: 60px 24px;
}

.results-card {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: 28px;
  padding: 48px 40px;
  max-width: 520px;
  width: 100%;
  text-align: center;
  box-shadow: var(--shadow-lg);
  animation: popIn 0.5s cubic-bezier(0.34, 1.4, 0.64, 1) both;
  position: relative;
  overflow: hidden;
}

.results-card::before {
  content: '';
  position: absolute;
  top: 0;
  left: 0;
  right: 0;
  height: 4px;
  background: linear-gradient(90deg, var(--accent), var(--accent2), var(--accent4));
}

@keyframes popIn {
  from {
    opacity: 0;
    transform: scale(0.92) translateY(24px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

.results-emoji {
  font-size: 64px;
  margin-bottom: 16px;
  display: block;
  line-height: 1;
}

.results-title {
  font-family: var(--font-display);
  font-size: 2.5rem;
  font-weight: 400;
  margin-bottom: 8px;
  letter-spacing: -0.02em;
}

.results-subtitle {
  color: var(--text2);
  font-size: 15px;
  margin-bottom: 32px;
  line-height: 1.5;
}

.score-circle {
  width: 140px;
  height: 140px;
  border-radius: 50%;
  border: 4px solid transparent;
  background:
    linear-gradient(var(--surface-solid), var(--surface-solid)) padding-box,
    linear-gradient(135deg, var(--accent), var(--accent2)) border-box;
  display: flex;
  flex-direction: column;
  align-items: center;
  justify-content: center;
  margin: 0 auto 32px;
  box-shadow: var(--shadow-md);
}

.score-number {
  font-family: var(--font-display);
  font-size: 3rem;
  line-height: 1;
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  -webkit-background-clip: text;
  background-clip: text;
  -webkit-text-fill-color: transparent;
}

.score-denom {
  font-size: 14px;
  font-weight: 600;
  color: var(--text3);
}

.results-stats {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px;
  margin-bottom: 32px;
}

.r-stat {
  background: var(--surface2);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
}

.r-stat-val {
  font-family: var(--font-display);
  font-size: 2rem;
  display: block;
  line-height: 1.1;
}

.r-stat:nth-child(1) .r-stat-val {
  color: var(--correct);
}

.r-stat:nth-child(2) .r-stat-val {
  color: var(--accent3);
}

.r-stat-label {
  font-size: 12px;
  font-weight: 600;
  color: var(--text3);
  margin-top: 4px;
  display: block;
}

.results-actions {
  display: flex;
  gap: 10px;
  flex-wrap: wrap;
  justify-content: center;
}

.btn-action {
  border-radius: 12px;
  padding: 12px 22px;
  font-family: var(--font);
  font-size: 14px;
  font-weight: 700;
  cursor: pointer;
  border: none;
  transition: var(--transition);
  display: flex;
  align-items: center;
  gap: 8px;
}

.btn-action.primary {
  background: linear-gradient(135deg, var(--accent), var(--accent2));
  color: #fff;
  box-shadow: 0 6px 20px var(--accent-glow);
}

.btn-action.primary:hover {
  transform: translateY(-2px);
  filter: brightness(1.05);
}

.btn-action.secondary {
  background: var(--surface2);
  color: var(--text);
  border: 1px solid var(--border);
}

.btn-action.secondary:hover {
  border-color: var(--accent);
  color: var(--accent);
  background: #fff;
}

/* ── REVIEW ── */
.review-header {
  padding: 20px 24px 0;
  max-width: 800px;
  margin: 0 auto;
  display: flex;
  align-items: center;
  justify-content: space-between;
  flex-wrap: wrap;
  gap: 12px;
}

.review-title {
  font-family: var(--font-display);
  font-size: 1.6rem;
  font-weight: 400;
}

.filter-group {
  display: flex;
  gap: 8px;
  flex-wrap: wrap;
}

.filter-btn {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  color: var(--text3);
  border-radius: 10px;
  padding: 7px 14px;
  font-size: 12px;
  font-weight: 700;
  cursor: pointer;
  font-family: var(--font);
  transition: var(--transition);
  box-shadow: var(--shadow-sm);
}

.filter-btn.active {
  border-color: var(--accent2);
  color: var(--accent2);
  background: rgba(99, 102, 241, 0.08);
}

.filter-btn.f-correct.active {
  border-color: var(--correct-border);
  color: var(--correct);
  background: var(--correct-bg);
}

.filter-btn.f-wrong.active {
  border-color: var(--wrong-border);
  color: var(--accent3);
  background: var(--wrong-bg);
}

.review-wrapper {
  max-width: 800px;
  margin: 0 auto;
  padding: 20px 24px 100px;
  display: flex;
  flex-direction: column;
  gap: 14px;
}

.review-item {
  background: var(--surface-solid);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  padding: 22px;
  border-left-width: 4px;
  box-shadow: var(--shadow-card);
}

.review-item.was-correct {
  border-left-color: var(--correct-border);
}

.review-item.was-wrong {
  border-left-color: var(--wrong-border);
}

.review-q {
  font-size: 15px;
  font-weight: 700;
  margin-bottom: 12px;
  line-height: 1.45;
}

.review-answer {
  display: flex;
  gap: 10px;
  align-items: flex-start;
  font-size: 14px;
  color: var(--text2);
  line-height: 1.6;
}

.review-marker {
  font-size: 16px;
  flex-shrink: 0;
}

.review-your {
  font-size: 13px;
  color: var(--accent3);
  margin-top: 6px;
  font-weight: 600;
}

::-webkit-scrollbar {
  width: 8px;
}

::-webkit-scrollbar-track {
  background: transparent;
}

::-webkit-scrollbar-thumb {
  background: rgba(15, 23, 42, 0.15);
  border-radius: 99px;
}

::-webkit-scrollbar-thumb:hover {
  background: rgba(15, 23, 42, 0.25);
}

@media (max-width: 640px) {
  #home {
    padding: 32px 16px 60px;
  }

  .quiz-topbar {
    padding: 12px 16px;
    gap: 10px;
    flex-wrap: wrap;
  }

  .quiz-title-bar {
    display: none;
  }

  .progress-wrap {
    order: 3;
    width: 100%;
    flex-basis: 100%;
  }

  .question-card {
    padding: 22px 18px;
  }

  .question-text {
    font-size: 1.2rem;
  }

  .results-card {
    padding: 32px 22px;
  }

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

  .btn-all {
    width: 100%;
    justify-content: center;
  }
}