/* ==========================================================================
   Composants — boutons, cartes, QCM, modales, etc.
   Conforme à REVISION_DESIGN_SYSTEM.md
   ========================================================================== */

/* ---------- Navigation ---------- */

.app-header {
  border-bottom: 1px solid var(--border);
  background: var(--bg-secondary);
  position: sticky;
  top: 0;
  z-index: 50;
}

.app-header__inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  padding: var(--space-4) 0;
}

.app-header__brand {
  display: flex;
  align-items: baseline;
  gap: var(--space-2);
  font-weight: 700;
  font-size: 1.1rem;
  color: var(--text-primary);
}

.app-header__brand small {
  font-weight: 500;
  font-size: 0.8rem;
  color: var(--text-muted);
}

.app-header__nav {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  flex-wrap: wrap;
}

.app-header__nav a {
  text-decoration: none;
}

/* ---------- Boutons ---------- */

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: var(--space-2);
  min-height: 44px;
  padding: var(--space-2) var(--space-5);
  border-radius: var(--radius-md);
  border: 1px solid transparent;
  font-weight: 600;
  font-size: 0.95rem;
  cursor: pointer;
  transition: background-color var(--transition-fast), border-color var(--transition-fast),
    color var(--transition-fast), transform var(--transition-fast), opacity var(--transition-fast);
  white-space: nowrap;
  text-decoration: none;
}

.btn:disabled,
.btn[aria-disabled="true"] {
  opacity: 0.5;
  cursor: not-allowed;
}

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

.btn-primary:hover:not(:disabled) {
  background: var(--accent-hover);
}

.btn-secondary {
  background: var(--surface-secondary);
  color: var(--text-primary);
  border-color: var(--border-strong);
}

.btn-secondary:hover:not(:disabled) {
  background: var(--surface-hover);
}

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

.btn-ghost:hover:not(:disabled) {
  background: var(--surface-hover);
  color: var(--text-primary);
}

.btn-danger {
  background: transparent;
  color: var(--error);
  border-color: var(--error);
}

.btn-danger:hover:not(:disabled) {
  background: var(--error-soft);
}

.btn-danger.btn-danger--solid {
  background: var(--error);
  color: #fff;
}

.btn-danger.btn-danger--solid:hover:not(:disabled) {
  opacity: 0.9;
}

.btn-block {
  width: 100%;
}

.btn-icon {
  width: 44px;
  height: 44px;
  padding: 0;
  flex-shrink: 0;
}

/* ---------- Cartes ---------- */

.card {
  background: var(--surface-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  box-shadow: var(--shadow-sm);
}

.card-interactive {
  cursor: pointer;
  transition: border-color var(--transition-fast), background-color var(--transition-fast),
    transform var(--transition-fast);
  text-align: left;
  width: 100%;
  display: block;
}

.card-interactive:hover,
.card-interactive:focus-visible {
  border-color: var(--border-strong);
  background: var(--surface-secondary);
  transform: translateY(-2px);
}

/* ---------- Cartes de cours ---------- */

.course-grid {
  display: grid;
  grid-template-columns: repeat(auto-fill, minmax(260px, 1fr));
  gap: var(--space-5);
}

.course-card {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.course-card__title {
  font-size: 1.1rem;
  font-weight: 700;
  color: var(--text-primary);
}

.course-card__meta {
  font-size: 0.875rem;
  color: var(--text-muted);
}

.course-card__stats {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  font-size: 0.85rem;
  color: var(--text-secondary);
}

.course-card--all {
  border-color: var(--accent);
  background: linear-gradient(180deg, var(--accent-soft), var(--surface-primary) 65%);
}

/* ---------- Cartes statistiques ---------- */

.stat-grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(150px, 1fr));
  gap: var(--space-4);
}

.stat-card {
  background: var(--surface-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-5);
  text-align: left;
  display: flex;
  flex-direction: column;
  gap: var(--space-1);
}

.stat-card__value {
  font-size: 1.9rem;
  font-weight: 700;
  color: var(--text-primary);
  font-variant-numeric: tabular-nums;
}

.stat-card__label {
  font-size: 0.85rem;
  color: var(--text-muted);
  font-weight: 500;
}

.stat-card__sub {
  font-size: 0.78rem;
  color: var(--text-muted);
}

.stat-card--accent .stat-card__value { color: var(--accent); }
.stat-card--success .stat-card__value { color: var(--success); }
.stat-card--warning .stat-card__value { color: var(--warning); }

/* ---------- Section headers ---------- */

.section {
  margin-top: var(--space-10);
}

.section__header {
  display: flex;
  align-items: baseline;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-4);
  flex-wrap: wrap;
}

.section__header p {
  margin: 0;
}

/* ---------- Barre de progression ---------- */

.progress {
  width: 100%;
  height: 8px;
  border-radius: 999px;
  background: var(--surface-secondary);
  overflow: hidden;
  border: 1px solid var(--border);
}

.progress-bar {
  height: 100%;
  background: var(--accent);
  border-radius: 999px;
  transition: width var(--transition-normal);
}

.progress-label {
  display: flex;
  justify-content: space-between;
  font-size: 0.85rem;
  color: var(--text-muted);
  margin-bottom: var(--space-2);
}

/* ---------- Écran de configuration de quiz ---------- */

.quiz-setup__options {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(90px, 1fr));
  gap: var(--space-2);
  margin: var(--space-4) 0;
}

.option-pill {
  border: 1px solid var(--border);
  background: var(--surface-secondary);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  padding: var(--space-3);
  min-height: 44px;
  font-weight: 600;
  cursor: pointer;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
  text-align: center;
}

.option-pill:hover {
  border-color: var(--border-strong);
}

.option-pill.selected {
  border-color: var(--accent);
  background: var(--accent-soft);
  color: var(--accent-hover);
}

.custom-number-field {
  display: flex;
  align-items: center;
  gap: var(--space-2);
}

.custom-number-field input {
  width: 100%;
  max-width: 140px;
  min-height: 44px;
  padding: var(--space-2) var(--space-3);
  border-radius: var(--radius-md);
  border: 1px solid var(--border);
  background: var(--surface-secondary);
  color: var(--text-primary);
}

.custom-number-field input:focus-visible {
  border-color: var(--accent);
}

.field-error {
  color: var(--error);
  font-size: 0.85rem;
  margin-top: var(--space-2);
  min-height: 1.2em;
}

/* ---------- Écran de QCM ---------- */

.quiz-meta {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  margin-bottom: var(--space-3);
  flex-wrap: wrap;
}

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

.quiz-meta__counter {
  font-variant-numeric: tabular-nums;
  color: var(--text-muted);
  font-size: 0.9rem;
}

.quiz-card {
  margin-top: var(--space-4);
}

.quiz-card__badge {
  display: inline-block;
  background: var(--info-soft);
  color: var(--info);
  border-radius: var(--radius-sm);
  padding: var(--space-1) var(--space-3);
  font-size: 0.78rem;
  font-weight: 600;
  margin-bottom: var(--space-4);
}

.quiz-card__question {
  font-size: 1.25rem;
  font-weight: 600;
  color: var(--text-primary);
  margin-bottom: var(--space-6);
  line-height: 1.5;
}

/* ---------- Propositions de réponse ---------- */

.answer-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
  list-style: none;
  margin: 0 0 var(--space-6) 0;
  padding: 0;
}

.answer-option {
  display: flex;
  align-items: flex-start;
  gap: var(--space-3);
  width: 100%;
  text-align: left;
  background: var(--surface-secondary);
  border: 2px solid var(--border);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  min-height: 44px;
  font-size: 1rem;
  color: var(--text-primary);
  cursor: pointer;
  transition: border-color var(--transition-fast), background-color var(--transition-fast);
}

.answer-option:hover:not(.disabled) {
  border-color: var(--border-strong);
  background: var(--surface-hover);
}

.answer-option.selected {
  border-color: var(--accent);
  background: var(--accent-soft);
}

.answer-option.correct {
  border-color: var(--success);
  background: var(--success-soft);
}

.answer-option.incorrect {
  border-color: var(--error);
  background: var(--error-soft);
}

.answer-option.disabled {
  cursor: default;
}

.answer-option__marker {
  flex-shrink: 0;
  width: 22px;
  height: 22px;
  border-radius: 50%;
  border: 2px solid var(--border-strong);
  display: flex;
  align-items: center;
  justify-content: center;
  margin-top: 2px;
  font-size: 0.75rem;
  font-weight: 700;
  color: transparent;
  background: var(--surface-primary);
  transition: all var(--transition-fast);
}

.answer-option[data-input-type="checkbox"] .answer-option__marker {
  border-radius: var(--radius-sm);
}

.answer-option.selected .answer-option__marker {
  border-color: var(--accent);
  background: var(--accent);
  color: #fff;
}

.answer-option.correct .answer-option__marker {
  border-color: var(--success);
  background: var(--success);
  color: #fff;
}

.answer-option.incorrect .answer-option__marker {
  border-color: var(--error);
  background: var(--error);
  color: #fff;
}

.answer-option__text {
  flex: 1;
}

.answer-option__status {
  flex-shrink: 0;
  font-size: 0.78rem;
  font-weight: 700;
  align-self: center;
}

.answer-option.correct .answer-option__status { color: var(--success); }
.answer-option.incorrect .answer-option__status { color: var(--error); }

.multi-answer-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-2);
  background: var(--accent-soft);
  color: var(--accent-hover);
  border-radius: var(--radius-sm);
  padding: var(--space-1) var(--space-3);
  font-size: 0.78rem;
  font-weight: 700;
  margin-bottom: var(--space-4);
}

/* ---------- Indice ---------- */

.hint-box {
  border: 1px solid var(--warning);
  background: var(--warning-soft);
  border-radius: var(--radius-md);
  padding: var(--space-4);
  margin-bottom: var(--space-6);
  color: var(--text-primary);
  font-size: 0.95rem;
  animation: fade-in var(--transition-normal);
}

.hint-box__label {
  font-weight: 700;
  color: var(--warning);
  display: flex;
  align-items: center;
  gap: var(--space-2);
  margin-bottom: var(--space-1);
}

/* ---------- Correction pédagogique ---------- */

.explanation-box {
  border-radius: var(--radius-md);
  padding: var(--space-5);
  margin-bottom: var(--space-6);
  border: 1px solid var(--border);
  animation: fade-in var(--transition-normal);
}

.explanation-box.success {
  border-color: var(--success);
  background: var(--success-soft);
}

.explanation-box.error {
  border-color: var(--error);
  background: var(--error-soft);
}

.explanation-box__title {
  display: flex;
  align-items: center;
  gap: var(--space-2);
  font-weight: 700;
  font-size: 1.05rem;
  margin-bottom: var(--space-3);
}

.explanation-box.success .explanation-box__title { color: var(--success); }
.explanation-box.error .explanation-box__title { color: var(--error); }

.explanation-box__row {
  font-size: 0.9rem;
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
}

.explanation-box__row strong {
  color: var(--text-primary);
}

.explanation-box__body {
  margin-top: var(--space-3);
  color: var(--text-primary);
  line-height: 1.65;
}

/* ---------- Formules / contenu technique ---------- */

.formula {
  overflow-x: auto;
  padding: var(--space-4);
  background: var(--bg-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  font-family: var(--font-mono);
  font-size: 0.92rem;
  margin: var(--space-3) 0;
}

/* ---------- Quiz footer / actions ---------- */

.quiz-actions {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  flex-wrap: wrap;
}

.quiz-actions__left {
  display: flex;
  gap: var(--space-2);
}

.quiz-quit {
  text-align: center;
  margin-top: var(--space-8);
}

/* ---------- Résultats ---------- */

.result-card {
  text-align: center;
}

.result-card__score {
  font-size: clamp(2.5rem, 8vw, 3.5rem);
  font-weight: 700;
  color: var(--text-primary);
  line-height: 1;
  margin-bottom: var(--space-2);
}

.result-card__percent {
  font-size: 1.5rem;
  font-weight: 600;
  margin-bottom: var(--space-6);
}

.result-card__percent.success { color: var(--success); }
.result-card__percent.warning { color: var(--warning); }
.result-card__percent.error { color: var(--error); }

.result-card__status {
  display: inline-block;
  font-size: 0.8rem;
  font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: var(--radius-sm);
  margin-bottom: var(--space-6);
  background: var(--surface-secondary);
  color: var(--text-muted);
}

.result-card__status.interrupted {
  background: var(--warning-soft);
  color: var(--warning);
}

.result-card__grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(120px, 1fr));
  gap: var(--space-4);
  margin: var(--space-6) 0;
  text-align: left;
}

.result-card__actions {
  display: flex;
  flex-wrap: wrap;
  gap: var(--space-3);
  justify-content: center;
  margin-top: var(--space-6);
}

.result-card__message {
  color: var(--text-secondary);
  margin-bottom: var(--space-2);
}

/* ---------- Modales ---------- */

.modal-overlay {
  position: fixed;
  inset: 0;
  background: rgba(2, 6, 16, 0.6);
  display: flex;
  align-items: center;
  justify-content: center;
  padding: var(--space-4);
  z-index: 100;
  animation: fade-in var(--transition-fast);
}

.modal {
  background: var(--surface-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  padding: var(--space-6);
  max-width: 440px;
  width: 100%;
  box-shadow: var(--shadow-md);
}

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

.modal__body {
  color: var(--text-secondary);
  margin-bottom: var(--space-6);
}

.modal__actions {
  display: flex;
  gap: var(--space-3);
  justify-content: flex-end;
  flex-wrap: wrap;
}

/* ---------- États vides ---------- */

.empty-state {
  text-align: center;
  padding: var(--space-10) var(--space-6);
  color: var(--text-muted);
}

.empty-state__icon {
  margin: 0 auto var(--space-4);
  opacity: 0.6;
}

.empty-state h3 {
  color: var(--text-primary);
  margin-bottom: var(--space-2);
}

/* ---------- Alerte erreur technique ---------- */

.alert-error {
  border: 1px solid var(--error);
  background: var(--error-soft);
  color: var(--text-primary);
  border-radius: var(--radius-md);
  padding: var(--space-5);
  display: flex;
  gap: var(--space-3);
  align-items: flex-start;
}

.alert-error__title {
  font-weight: 700;
  color: var(--error);
  margin-bottom: var(--space-1);
}

/* ---------- Mes erreurs ---------- */

.mistake-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-3);
}

.mistake-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-4);
  flex-wrap: wrap;
}

.mistake-item__course {
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--accent);
  text-transform: uppercase;
  letter-spacing: 0.02em;
}

.mistake-item__question {
  color: var(--text-primary);
  font-weight: 500;
  margin-top: var(--space-1);
}

.mistake-item__stats {
  display: flex;
  gap: var(--space-4);
  font-size: 0.82rem;
  color: var(--text-muted);
  flex-shrink: 0;
}

.mastery-badge {
  display: inline-flex;
  align-items: center;
  gap: var(--space-1);
  font-size: 0.78rem;
  font-weight: 600;
  padding: var(--space-1) var(--space-3);
  border-radius: 999px;
}

.mastery-badge.to-review {
  background: var(--error-soft);
  color: var(--error);
}

.mastery-badge.in-progress {
  background: var(--warning-soft);
  color: var(--warning);
}

.mastery-badge.mastered {
  background: var(--success-soft);
  color: var(--success);
}

/* ---------- Historique ---------- */

.history-list {
  display: flex;
  flex-direction: column;
  gap: var(--space-2);
}

.history-item {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: var(--space-3);
  padding: var(--space-3) var(--space-4);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  background: var(--surface-primary);
  flex-wrap: wrap;
}

.history-item__course {
  font-weight: 600;
  color: var(--text-primary);
}

.history-item__date {
  font-size: 0.8rem;
  color: var(--text-muted);
}

.history-item__score {
  font-weight: 700;
  font-variant-numeric: tabular-nums;
}

/* ---------- Theme toggle ---------- */

.theme-toggle {
  background: var(--surface-secondary);
  border: 1px solid var(--border);
  border-radius: var(--radius-md);
  width: 44px;
  height: 44px;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
  color: var(--text-secondary);
  transition: background-color var(--transition-fast), color var(--transition-fast);
}

.theme-toggle:hover {
  background: var(--surface-hover);
  color: var(--text-primary);
}

/* ---------- Mini bar chart (progression) ---------- */

.mini-bars {
  display: flex;
  align-items: flex-end;
  gap: var(--space-2);
  height: 60px;
}

.mini-bars__bar {
  flex: 1;
  background: var(--accent-soft);
  border-radius: var(--radius-sm) var(--radius-sm) 0 0;
  position: relative;
  min-height: 4px;
  transition: height var(--transition-normal);
}

.mini-bars__bar.is-pass {
  background: var(--accent);
}

/* ---------- Animations ---------- */

@keyframes fade-in {
  from { opacity: 0; transform: translateY(4px); }
  to { opacity: 1; transform: translateY(0); }
}

.hero {
  padding: var(--space-10) 0 var(--space-6);
}

.hero h1 {
  margin-bottom: var(--space-2);
}

.hero__actions {
  display: flex;
  gap: var(--space-3);
  flex-wrap: wrap;
  margin-top: var(--space-6);
}

.tag-row {
  display: flex;
  gap: var(--space-2);
  flex-wrap: wrap;
  margin-top: var(--space-2);
}

.tag {
  font-size: 0.75rem;
  font-weight: 600;
  padding: var(--space-1) var(--space-2);
  border-radius: var(--radius-sm);
  background: var(--surface-secondary);
  color: var(--text-muted);
}


/* ========================================================================== 
   Visual refresh — interface de révision moderne
   ========================================================================== */

.app-header {
  background: var(--header-bg);
  backdrop-filter: blur(18px) saturate(135%);
  -webkit-backdrop-filter: blur(18px) saturate(135%);
  border-bottom: 1px solid var(--border);
  box-shadow: 0 1px 0 rgba(255,255,255,.02);
}

.app-header__inner { min-height: 72px; padding: .75rem 0; }
.app-header__brand { font-size: 1.05rem; letter-spacing: -.02em; }
.app-header__brand::before {
  content: "R";
  width: 36px; height: 36px; display: grid; place-items: center;
  border-radius: 11px; color: #fff; font-weight: 800;
  background: linear-gradient(135deg, var(--accent), var(--info));
  box-shadow: var(--shadow-accent);
}
.app-header__brand small { opacity: .78; }

.btn {
  border-radius: 12px;
  min-height: 42px;
  font-weight: 700;
  letter-spacing: -.01em;
  box-shadow: none;
}
.btn:hover:not(:disabled) { transform: translateY(-1px); }
.btn:active:not(:disabled) { transform: translateY(0) scale(.985); }
.btn-primary {
  border-color: transparent;
  background: linear-gradient(135deg, var(--accent), var(--accent-strong));
  box-shadow: var(--shadow-accent);
}
.btn-primary:hover:not(:disabled) { background: linear-gradient(135deg, var(--accent-hover), var(--accent)); }
.btn-secondary { background: var(--surface-primary); border-color: var(--border); box-shadow: var(--shadow-sm); }
.btn-ghost { border: 1px solid transparent; }
.btn-ghost:hover:not(:disabled) { border-color: var(--border); text-decoration: none; }

.card {
  position: relative;
  overflow: hidden;
  background: var(--surface-primary);
  border: 1px solid var(--border);
  border-radius: var(--radius-lg);
  box-shadow: var(--shadow-sm);
  backdrop-filter: blur(8px);
}
.card::before {
  content: "";
  position: absolute;
  inset: 0 0 auto 0;
  height: 1px;
  background: linear-gradient(90deg, transparent, rgba(255,255,255,.16), transparent);
  pointer-events: none;
}
.card-interactive { transition: transform var(--transition-normal), box-shadow var(--transition-normal), border-color var(--transition-normal), background-color var(--transition-normal); }
.card-interactive:hover, .card-interactive:focus-visible {
  transform: translateY(-4px);
  box-shadow: var(--shadow-md);
  border-color: color-mix(in srgb, var(--accent) 40%, var(--border));
  background: var(--surface-primary);
}

.hero { padding: clamp(2.5rem, 8vw, 5.5rem) 0 2.25rem; }
.hero h1 {
  max-width: 850px;
  background: linear-gradient(120deg, var(--text-primary) 15%, var(--accent-hover) 58%, var(--info) 100%);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero p { font-size: 1.07rem; margin-top: .8rem; }
.hero__actions { margin-top: 1.75rem; }

.section { margin-top: 3rem; }
.section__header { margin-bottom: 1.1rem; }
.section__header h2 { font-size: 1.25rem; letter-spacing: -.02em; }

.course-grid { gap: 1rem; }
.course-card { min-height: 185px; padding: 1.35rem; justify-content: space-between; }
.course-card__title { font-size: 1.08rem; }
.course-card__meta { color: var(--text-muted); }
.course-card__stats { padding-top: .6rem; border-top: 1px solid var(--border); }
.course-card--all {
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border));
  background:
    radial-gradient(circle at top right, var(--accent-soft), transparent 45%),
    var(--surface-primary);
}

.stat-grid { gap: .85rem; }
.stat-card {
  border-radius: 18px;
  background: linear-gradient(180deg, var(--surface-primary), var(--accent-softer));
  box-shadow: var(--shadow-sm);
}
.stat-card__value { font-size: 2.05rem; letter-spacing: -.045em; }

.progress { height: 10px; background: var(--bg-secondary); border: 0; box-shadow: inset 0 0 0 1px var(--border); }
.progress-bar { background: linear-gradient(90deg, var(--accent), var(--info)); box-shadow: 0 0 18px var(--accent-soft); }

.quiz-meta { margin-bottom: 1rem; }
.quiz-meta__course {
  display: inline-flex; align-items: center; gap: .45rem;
  padding: .35rem .65rem; border-radius: 999px;
  background: var(--accent-soft); color: var(--accent-hover); font-size: .86rem;
}
.quiz-meta__counter { font-weight: 650; }

.quiz-card { padding: clamp(1.35rem, 4vw, 2.15rem); box-shadow: var(--shadow-md); }
.quiz-card__badge, .multi-answer-badge {
  border-radius: 999px;
  border: 1px solid color-mix(in srgb, currentColor 20%, transparent);
}
.quiz-card__question {
  font-size: clamp(1.2rem, 2vw, 1.45rem);
  font-weight: 720;
  letter-spacing: -.02em;
  margin-bottom: 1.7rem;
}

.answer-list { gap: .75rem; }
.answer-option {
  position: relative;
  padding: 1rem 1.05rem;
  border: 1px solid var(--border);
  border-radius: 15px;
  background: color-mix(in srgb, var(--surface-secondary) 86%, transparent);
  transition: transform var(--transition-fast), border-color var(--transition-fast), background-color var(--transition-fast), box-shadow var(--transition-fast);
}
.answer-option:hover:not(.disabled) {
  transform: translateY(-1px);
  border-color: color-mix(in srgb, var(--accent) 45%, var(--border-strong));
  background: var(--surface-hover);
  box-shadow: var(--shadow-sm);
}
.answer-option.selected { border-color: var(--accent); background: var(--accent-soft); box-shadow: inset 0 0 0 1px var(--accent); }
.answer-option.correct { border-color: var(--success); background: var(--success-soft); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--success) 60%, transparent); }
.answer-option.incorrect { border-color: var(--error); background: var(--error-soft); box-shadow: inset 0 0 0 1px color-mix(in srgb, var(--error) 60%, transparent); }
.answer-option__marker { width: 24px; height: 24px; background: var(--bg-elevated); }

.hint-box, .explanation-box, .alert-error { border-width: 1px; box-shadow: var(--shadow-sm); }
.explanation-box { padding: 1.25rem; }
.explanation-box__body { line-height: 1.75; }

.formula { border-radius: 14px; background: rgba(0,0,0,.16); box-shadow: inset 0 0 0 1px var(--border); }
[data-theme="light"] .formula { background: #f6f8fb; }

.quiz-actions { padding-top: .25rem; }

.result-card { padding: clamp(1.5rem, 4vw, 2.5rem); }
.result-card__score { font-size: clamp(3rem, 10vw, 4.6rem); letter-spacing: -.06em; }
.result-card__percent { letter-spacing: -.025em; }
.result-card__grid .stat-card { text-align: center; }

.modal-overlay { backdrop-filter: blur(8px); background: rgba(2,6,16,.68); }
.modal { border-radius: 22px; box-shadow: var(--shadow-lg); }

.option-pill {
  border-radius: 12px;
  background: var(--surface-primary);
  box-shadow: 0 1px 0 rgba(255,255,255,.02);
}
.option-pill:hover { background: var(--surface-hover); }
.option-pill.selected { box-shadow: inset 0 0 0 1px var(--accent); }

.theme-toggle {
  border-radius: 12px;
  background: var(--surface-primary);
  box-shadow: var(--shadow-sm);
}

.history-item, .mistake-item {
  transition: border-color var(--transition-fast), background-color var(--transition-fast), transform var(--transition-fast);
}
.history-item:hover { border-color: var(--border-strong); background: var(--surface-secondary); transform: translateX(2px); }
.mistake-item { padding: 1rem 1.1rem; border: 1px solid var(--border); border-radius: 15px; background: var(--surface-primary); }
.mistake-item:hover { border-color: var(--border-strong); }

.tag { border-radius: 999px; border: 1px solid var(--border); padding-inline: .65rem; }

@keyframes fade-in {
  from { opacity: 0; transform: translateY(8px) scale(.995); }
  to { opacity: 1; transform: translateY(0) scale(1); }
}