/* ==========================================================================
   Haber-Bosch : sous pression — feuille de style
   Thème clair/sombre via variables CSS, options d'accessibilité (taille de
   police, police dyslexie), mise en page responsive mobile-first.
   ========================================================================== */

:root {
  --color-bg: #f6f3ec;
  --color-surface: #ffffff;
  --color-surface-alt: #eef1ea;
  --color-text: #1c2420;
  --color-text-muted: #4d5a52;
  --color-primary: #1f6f4a;
  --color-primary-dark: #154f34;
  --color-primary-contrast: #ffffff;
  --color-accent: #a15c1f;
  --color-success-bg: #e3f3e6;
  --color-success-text: #1b5e20;
  --color-success-border: #2e7d32;
  --color-error-bg: #fbe9e7;
  --color-error-text: #7a2418;
  --color-error-border: #b3261e;
  --color-border: #d9d2c1;
  --color-focus: #0b57d0;

  --font-main: "Segoe UI", Verdana, Arial, sans-serif;
  --font-size-scale: 1;
  --radius: 14px;
  --radius-sm: 8px;
  --shadow: 0 2px 10px rgba(28, 36, 32, 0.08);
  --max-width: 46rem;
}

/* Thème sombre : suit le système, sauf choix explicite de l'utilisateur */
@media (prefers-color-scheme: dark) {
  :root:not([data-theme="light"]) {
    --color-bg: #14181a;
    --color-surface: #1e2624;
    --color-surface-alt: #232c29;
    --color-text: #edf1ee;
    --color-text-muted: #b7c2bc;
    --color-primary: #4caf7d;
    --color-primary-dark: #2f8f5f;
    --color-primary-contrast: #0b1310;
    --color-accent: #d99a56;
    --color-success-bg: #163521;
    --color-success-text: #8fe0a3;
    --color-success-border: #4caf7d;
    --color-error-bg: #3a1c18;
    --color-error-text: #ffb4a8;
    --color-error-border: #e0665a;
    --color-border: #3a453f;
    --color-focus: #8ab4ff;
  }
}

/* Thème sombre forcé par le bouton bascule */
:root[data-theme="dark"] {
  --color-bg: #14181a;
  --color-surface: #1e2624;
  --color-surface-alt: #232c29;
  --color-text: #edf1ee;
  --color-text-muted: #b7c2bc;
  --color-primary: #4caf7d;
  --color-primary-dark: #2f8f5f;
  --color-primary-contrast: #0b1310;
  --color-accent: #d99a56;
  --color-success-bg: #163521;
  --color-success-text: #8fe0a3;
  --color-success-border: #4caf7d;
  --color-error-bg: #3a1c18;
  --color-error-text: #ffb4a8;
  --color-error-border: #e0665a;
  --color-border: #3a453f;
  --color-focus: #8ab4ff;
}

/* Police dyslexie : OpenDyslexic (licence SIL OFL 1.1), hébergée localement
   dans fonts/ — voir fonts/OFL-LICENSE.txt. Chargée uniquement quand le mode
   dyslexie est activé (le navigateur ne télécharge la police qu'à l'usage). */
@font-face {
  font-family: "OpenDyslexic";
  src: url("fonts/OpenDyslexic-Regular.woff2") format("woff2");
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: "OpenDyslexic";
  src: url("fonts/OpenDyslexic-Bold.woff2") format("woff2");
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

* {
  box-sizing: border-box;
}

html {
  font-size: calc(16px * var(--font-size-scale));
}

body {
  margin: 0;
  min-height: 100vh;
  background: var(--color-bg);
  color: var(--color-text);
  font-family: var(--font-main);
  line-height: 1.6;
  -webkit-text-size-adjust: 100%;
  overflow-x: hidden;
}

/* Police dyslexie : OpenDyslexic, avec repli sur des polices lisibles */
body.dyslexia-mode {
  font-family: "OpenDyslexic", Verdana, "Comic Sans MS", Tahoma, sans-serif;
  letter-spacing: 0.03em;
  word-spacing: 0.12em;
  line-height: 1.9;
}

.skip-link {
  position: absolute;
  left: -999px;
  top: 0;
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  padding: 0.75rem 1rem;
  border-radius: 0 0 var(--radius-sm) 0;
  z-index: 100;
}

.skip-link:focus {
  left: 0;
}

:focus-visible {
  outline: 3px solid var(--color-focus);
  outline-offset: 2px;
}

img, svg {
  max-width: 100%;
}

/* Indices des formules chimiques (N<sub>2</sub>, NH<sub>3</sub>…) : taille
   contrôlée explicitement pour rester lisible avec toutes les polices,
   y compris OpenDyslexic. */
sub {
  font-size: 0.72em;
  vertical-align: sub;
  line-height: 0;
}

/* ---------------------------- En-tête ---------------------------- */

.app-header {
  background: var(--color-surface);
  border-bottom: 1px solid var(--color-border);
  position: sticky;
  top: 0;
  z-index: 10;
}

.app-header__inner {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 0.75rem 1rem;
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 0.5rem;
}

.app-title {
  margin: 0;
  font-weight: 700;
  font-size: 1.05rem;
}

.a11y-toolbar {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  gap: 0.4rem;
}

.a11y-group {
  display: inline-flex;
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
  overflow: hidden;
}

.a11y-btn {
  background: var(--color-surface-alt);
  color: var(--color-text);
  border: none;
  border-right: 1px solid var(--color-border);
  padding: 0.4rem 0.65rem;
  font-size: 0.85rem;
  cursor: pointer;
  font-family: inherit;
}

.a11y-group .a11y-btn:last-child {
  border-right: none;
}

.a11y-toggle {
  border: 1px solid var(--color-border);
  border-radius: var(--radius-sm);
}

.a11y-btn:hover {
  background: var(--color-surface);
}

.a11y-btn[aria-pressed="true"] {
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  border-color: var(--color-primary);
}

/* ---------------------------- Contenu principal ---------------------------- */

.app-main {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 1.25rem 1rem 3rem;
}

.screen.hidden {
  display: none;
}

.card {
  background: var(--color-surface);
  border: 1px solid var(--color-border);
  border-radius: var(--radius);
  box-shadow: var(--shadow);
  padding: 1.5rem;
}

.eyebrow {
  text-transform: uppercase;
  letter-spacing: 0.06em;
  font-size: 0.78rem;
  font-weight: 700;
  color: var(--color-primary-dark);
  margin: 0 0 0.5rem;
}

h1 {
  margin-top: 0;
  font-size: 1.5rem;
  line-height: 1.3;
}

h2 {
  font-size: 1.15rem;
}

.card--intro p {
  color: var(--color-text-muted);
}

.source-note {
  margin-top: 1.5rem;
  padding-top: 1rem;
  border-top: 1px solid var(--color-border);
  font-size: 0.8rem;
  color: var(--color-text-muted);
}

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

.btn {
  font-family: inherit;
  font-size: 1rem;
  font-weight: 600;
  padding: 0.7rem 1.4rem;
  border-radius: var(--radius-sm);
  border: 2px solid transparent;
  cursor: pointer;
  min-height: 44px;
}

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

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

.btn--primary:disabled {
  opacity: 0.5;
  cursor: not-allowed;
}

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

.btn--ghost:hover {
  background: var(--color-surface-alt);
}

/* ---------------------------- Zone de jeu ---------------------------- */

.game-status {
  display: flex;
  justify-content: space-between;
  align-items: center;
  margin-bottom: 0.75rem;
  font-weight: 700;
  font-size: 0.9rem;
  color: var(--color-text-muted);
  flex-wrap: wrap;
  gap: 0.4rem;
}

.question-context {
  background: var(--color-surface-alt);
  border-left: 4px solid var(--color-accent);
  padding: 0.75rem 1rem;
  border-radius: var(--radius-sm);
  margin-bottom: 1rem;
  font-size: 0.95rem;
}

.question-context.hidden {
  display: none;
}

.question-prompt {
  margin-top: 0;
}

.answer-area {
  display: flex;
  flex-direction: column;
  gap: 0.6rem;
  margin: 1rem 0;
}

/* QCM */
.option-btn {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-align: left;
  background: var(--color-surface-alt);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 1rem;
  font-family: inherit;
  font-size: 1rem;
  color: var(--color-text);
  cursor: pointer;
  width: 100%;
}

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

.option-btn[aria-pressed="true"] {
  border-color: var(--color-primary);
  background: color-mix(in srgb, var(--color-primary) 15%, var(--color-surface-alt));
  font-weight: 700;
}

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

.option-btn.incorrect {
  border-color: var(--color-error-border);
  background: var(--color-error-bg);
  color: var(--color-error-text);
}

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

/* Fill-blank */
.fill-blank-row {
  display: flex;
  flex-direction: column;
  gap: 0.4rem;
}

.fill-blank-row label {
  font-weight: 600;
}

.fill-blank-row input[type="text"] {
  font-family: inherit;
  font-size: 1.05rem;
  padding: 0.65rem 0.8rem;
  border-radius: var(--radius-sm);
  border: 2px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  max-width: 20rem;
}

.fill-blank-row input[type="text"]:focus {
  border-color: var(--color-primary);
}

/* Association (correspondance) */
.match-row {
  display: flex;
  flex-direction: column;
  gap: 0.35rem;
  background: var(--color-surface-alt);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.75rem 0.9rem;
}

.match-row label {
  font-weight: 700;
}

.match-row select {
  font-family: inherit;
  font-size: 0.98rem;
  padding: 0.55rem 0.7rem;
  border-radius: var(--radius-sm);
  border: 2px solid var(--color-border);
  background: var(--color-surface);
  color: var(--color-text);
  min-height: 44px;
}

.match-row select:focus {
  border-color: var(--color-primary);
}

.match-row.correct {
  border-color: var(--color-success-border);
  background: var(--color-success-bg);
}

.match-row.correct label,
.match-row.correct select {
  color: var(--color-success-text);
}

.match-row.incorrect {
  border-color: var(--color-error-border);
  background: var(--color-error-bg);
}

.match-row.incorrect label,
.match-row.incorrect select {
  color: var(--color-error-text);
}

/* Ordering */
.order-pool, .order-sequence {
  display: flex;
  flex-direction: column;
  gap: 0.5rem;
}

.order-block-label {
  font-size: 0.85rem;
  font-weight: 700;
  color: var(--color-text-muted);
  text-transform: uppercase;
  letter-spacing: 0.04em;
  margin: 0.5rem 0 0.2rem;
}

.order-btn {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  text-align: left;
  background: var(--color-surface-alt);
  border: 2px solid var(--color-border);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.9rem;
  font-family: inherit;
  font-size: 0.98rem;
  color: var(--color-text);
  cursor: pointer;
  width: 100%;
}

.order-btn:hover:not(:disabled) {
  border-color: var(--color-primary);
}

.order-btn:disabled {
  opacity: 0.4;
  cursor: default;
}

.order-sequence-item {
  display: flex;
  align-items: center;
  gap: 0.6rem;
  background: var(--color-surface);
  border: 2px solid var(--color-primary);
  border-radius: var(--radius-sm);
  padding: 0.65rem 0.9rem;
  font-size: 0.98rem;
}

.order-sequence-item.correct {
  border-color: var(--color-success-border);
  background: var(--color-success-bg);
  color: var(--color-success-text);
}

.order-sequence-item.incorrect {
  border-color: var(--color-error-border);
  background: var(--color-error-bg);
  color: var(--color-error-text);
}

.order-sequence-empty {
  color: var(--color-text-muted);
  font-style: italic;
  font-size: 0.9rem;
}

.step-number {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-width: 1.6rem;
  height: 1.6rem;
  border-radius: 50%;
  background: var(--color-primary);
  color: var(--color-primary-contrast);
  font-weight: 700;
  font-size: 0.85rem;
  flex-shrink: 0;
}

/* ---------------------------- Retour / feedback ---------------------------- */

.feedback-area {
  border-radius: var(--radius-sm);
  padding: 0.9rem 1rem;
  margin-top: 0.5rem;
  border: 2px solid var(--color-border);
}

.feedback-area.hidden {
  display: none;
}

.feedback-area.is-correct {
  background: var(--color-success-bg);
  border-color: var(--color-success-border);
  color: var(--color-success-text);
}

.feedback-area.is-incorrect {
  background: var(--color-error-bg);
  border-color: var(--color-error-border);
  color: var(--color-error-text);
}

.feedback-title {
  font-weight: 700;
  margin: 0 0 0.35rem;
}

.feedback-text {
  margin: 0;
  color: var(--color-text);
}

.action-row {
  display: flex;
  flex-wrap: wrap;
  gap: 0.6rem;
  justify-content: flex-end;
  margin-top: 1.25rem;
}

.action-row .hidden {
  display: none;
}

/* ---------------------------- Bilan ---------------------------- */

.card--debrief p {
  color: var(--color-text-muted);
}

#debrief-score {
  color: var(--color-primary-dark);
}

/* ---------------------------- Pied de page ---------------------------- */

.app-footer {
  text-align: center;
  padding: 1.5rem 1rem 2.5rem;
  color: var(--color-text-muted);
  font-size: 0.8rem;
}

/* ---------------------------- Responsive ---------------------------- */

@media (max-width: 480px) {
  .app-header__inner {
    flex-direction: column;
    align-items: flex-start;
  }

  h1 {
    font-size: 1.3rem;
  }

  .card {
    padding: 1.1rem;
  }

  .action-row {
    justify-content: stretch;
  }

  .action-row .btn {
    flex: 1 1 auto;
  }
}

/* Respect des préférences de mouvement réduit */
@media (prefers-reduced-motion: reduce) {
  * {
    transition: none !important;
    animation: none !important;
  }
}