/**
 * Grouvel - Page de révision du français (francais.html)
 * Couvre : navigation, grammaire, conjugaisons, layout responsive.
 */

    :root {
      color-scheme: light dark;
      --accent: #2563eb;
      --accent-soft: rgba(37, 99, 235, 0.12);
      --accent-strong: #1d4ed8;
      --accent-warm: #f97316;
      --bg: radial-gradient(circle at 25% 20%, #f5f9ff 0%, #ffffff 75%);
      --text: #1f2937;
      --muted: #4b5563;
      --card: rgba(255, 255, 255, 0.92);
      --border: rgba(15, 23, 42, 0.08);
    }
    @media (prefers-color-scheme: dark) {
      :root {
        --accent: #60a5fa;
        --accent-soft: rgba(96, 165, 250, 0.15);
        --accent-strong: #3b82f6;
        --accent-warm: #fb923c;
        --bg: radial-gradient(circle at 25% 20%, #141a2e 0%, #16213e 75%);
        --text: #e8e8f0;
        --muted: #9ca3af;
        --card: rgba(30, 30, 50, 0.92);
        --border: rgba(255, 255, 255, 0.1);
      }
    }
    * {
      box-sizing: border-box;
    }
    body {
      margin: 0;
      font-family: "Inter", -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, Oxygen, sans-serif;
      background: var(--bg);
      color: var(--text);
      display: flex;
      flex-direction: column;
      min-height: 100vh;
    }
    header {
      text-align: center;
      padding: 48px 16px 24px;
    }
    h1 {
      margin: 0;
      font-size: 2.9rem;
      color: var(--accent-strong);
    }
    header p {
      max-width: 720px;
      margin: 1em auto 2em;
      color: var(--muted);
      font-size: 1.05rem;
    }
    .nav-buttons {
      display: flex;
      justify-content: center;
      gap: 1em;
      flex-wrap: wrap;
      margin-top: 16px;
    }
    .btn {
      display: inline-flex;
      align-items: center;
      gap: 0.5em;
      padding: 0.85em 1.6em;
      border-radius: 10px;
      text-decoration: none;
      font-weight: 600;
      box-shadow: 0 10px 24px rgba(37, 99, 235, 0.2);
      transition: transform 0.25s ease, box-shadow 0.25s ease;
    }
    .btn.primary {
      background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%);
      color: #fff;
    }
    .btn.secondary {
      background: linear-gradient(135deg, #f97316 0%, #ea580c 100%);
      color: #fff;
      box-shadow: 0 10px 24px rgba(249, 115, 22, 0.2);
    }
    .btn:focus-visible {
      outline: 3px solid var(--accent-soft);
      outline-offset: 2px;
    }
    .btn:hover {
      transform: translateY(-2px) scale(1.02);
    }

    main {
      flex: 1;
      width: 100%;
      max-width: 1160px;
      margin: 0 auto;
      padding: 0 20px 64px;
    }
    .section-intro {
      margin-bottom: 48px;
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: 20px;
      padding: 2.4em 2.8em;
      box-shadow: 0 18px 44px rgba(15, 23, 42, 0.08);
    }
    .section-intro h2 {
      margin: 0 0 0.6em;
      font-size: 1.9rem;
      color: var(--accent-strong);
    }
    .section-intro p {
      margin: 0.4em 0;
      color: var(--muted);
      line-height: 1.7;
    }
    .pdf-hint {
      margin-top: 1.2em;
      font-style: italic;
      color: #6b7280;
    }
    .sub-nav {
      display: flex;
      flex-wrap: wrap;
      gap: 0.8em;
      margin-top: 1.6em;
    }
    .sub-nav a {
      padding: 0.6em 1.2em;
      border-radius: 999px;
      background: var(--accent-soft);
      color: var(--accent-strong);
      text-decoration: none;
      font-weight: 600;
      font-size: 0.95rem;
      transition: background 0.2s ease, transform 0.2s ease;
    }
    .sub-nav a:hover {
      background: rgba(37, 99, 235, 0.18);
      transform: translateY(-2px);
    }

    .grammar-grid,
    .conjugation-grid {
      display: grid;
      gap: 1.6em;
    }
    .grammar-card,
    .conjugation-card {
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: 18px;
      padding: 1.9em 2.1em;
      box-shadow: 0 14px 36px rgba(15, 23, 42, 0.08);
    }
    .grammar-card h3,
    .conjugation-card h3 {
      margin: 0 0 0.6em;
      font-size: 1.45rem;
      color: var(--accent-strong);
    }
    .grammar-card h4 {
      margin: 1.1em 0 0.6em;
      font-size: 1.1rem;
      color: var(--accent);
    }
    .grammar-card p,
    .conjugation-card p {
      margin: 0.4em 0;
      line-height: 1.65;
      color: var(--muted);
    }
    .example {
      margin: 0.8em 0;
      padding: 0.9em 1.1em;
      background: rgba(37, 99, 235, 0.06);
      border-radius: 12px;
      color: #1e3a8a;
      font-weight: 500;
    }
    .mini-exo {
      margin-top: 0.8em;
      padding: 0.85em 1.1em;
      border-left: 4px solid var(--accent);
      background: rgba(37, 99, 235, 0.08);
      border-radius: 12px 12px 12px 6px;
      color: #1f2937;
      font-weight: 500;
    }

    .element-list {
      display: grid;
      grid-template-columns: repeat(auto-fit, minmax(180px, 1fr));
      gap: 0.75em;
      margin: 1em 0;
    }
    .element-pill {
      padding: 0.85em 1em;
      border-radius: 12px;
      background: rgba(249, 115, 22, 0.12);
      color: #9a3412;
      font-weight: 600;
      text-align: center;
    }

    .table-wrapper {
      overflow-x: auto;
      margin-top: 1.2em;
    }
    table {
      width: 100%;
      border-collapse: collapse;
      min-width: 820px;
      font-size: 0.95rem;
    }
    th, td {
      border: 1px solid rgba(148, 163, 184, 0.4);
      padding: 0.8em;
      vertical-align: top;
      text-align: left;
    }
    thead th {
      background: rgba(37, 99, 235, 0.12);
      color: #1d4ed8;
      font-weight: 700;
    }
    tbody tr:nth-child(even) {
      background: rgba(37, 99, 235, 0.04);
    }
    .tense-tag {
      display: inline-block;
      margin-bottom: 0.5em;
      padding: 0.3em 0.75em;
      border-radius: 999px;
      font-size: 0.85rem;
      font-weight: 600;
      color: var(--accent-strong);
      background: rgba(37, 99, 235, 0.16);
    }
    .verbs-list {
      list-style: none;
      padding: 0;
      margin: 0.6em 0;
      display: grid;
      gap: 0.35em;
    }
    .verbs-list li {
      line-height: 1.5;
      color: var(--text);
    }
    .group-divider td {
      background: rgba(37, 99, 235, 0.08);
      color: var(--accent-strong);
      font-weight: 700;
      letter-spacing: 0.02em;
      text-transform: uppercase;
      padding: 0.7em 0.9em;
    }
    .verb-group {
      text-align: center;
      vertical-align: middle;
    }
    .group-tag {
      display: inline-flex;
      align-items: center;
      justify-content: center;
      padding: 0.3em 0.75em;
      border-radius: 999px;
      font-size: 0.82rem;
      font-weight: 600;
      background: rgba(37, 99, 235, 0.12);
      color: var(--accent-strong);
    }
    .group-tag.group-one {
      background: rgba(56, 189, 248, 0.18);
      color: #0369a1;
    }
    .group-tag.group-two {
      background: rgba(16, 185, 129, 0.18);
      color: #047857;
    }
    .group-tag.group-aux {
      background: rgba(249, 115, 22, 0.18);
      color: var(--accent-warm);
    }
    .group-tag.group-three {
      background: rgba(99, 102, 241, 0.16);
      color: #4338ca;
    }
    .verbs-empty {
      margin: 0;
      font-style: italic;
      color: var(--muted);
    }
    .group-note {
      margin: 1em 0;
      color: var(--muted);
      font-size: 0.95rem;
    }

    .flashcard-controls {
      background: rgba(37, 99, 235, 0.06);
      border: 1px solid rgba(37, 99, 235, 0.2);
      border-radius: 14px;
      padding: 1.2em 1.4em;
      margin-bottom: 1.6em;
    }
    .flashcard-controls fieldset {
      margin: 0;
      border: none;
      padding: 0;
      display: grid;
      gap: 0.8em;
    }
    .flashcard-controls legend {
      font-weight: 600;
      color: var(--accent-strong);
      margin-bottom: 0.4em;
    }
    .flashcard-controls label {
      display: inline-flex;
      align-items: center;
      gap: 0.5em;
      font-size: 0.95rem;
      color: var(--text);
      cursor: pointer;
    }
    .flashcard-controls input[type="checkbox"] {
      width: 18px;
      height: 18px;
      accent-color: var(--accent-strong);
    }

    .flashcard-shell {
      border: 1px solid var(--border);
      border-radius: 16px;
      padding: 1.8em 1.9em;
      background: rgba(255, 255, 255, 0.96);
      box-shadow: 0 12px 30px rgba(37, 99, 235, 0.12);
    }
    .flashcard-head h3 {
      margin: 0;
      font-size: 1.6rem;
      color: var(--accent-strong);
    }
    .flashcard-head p {
      margin: 0.4em 0 1.2em;
      color: var(--muted);
      font-size: 0.98rem;
    }
    .flashcard-tense-grid {
      display: grid;
      gap: 1em;
    }
    .flashcard-tense {
      border: 1px solid rgba(15, 23, 42, 0.08);
      border-radius: 12px;
      padding: 1.1em 1.3em;
      background: rgba(37, 99, 235, 0.03);
    }
    .flashcard-tense h4 {
      margin: 0 0 0.6em;
      font-size: 1.05rem;
      color: var(--accent-strong);
    }
    .flashcard-tense ul {
      list-style: none;
      padding: 0;
      margin: 0;
      display: grid;
      gap: 0.35em;
    }
    .flashcard-tense li {
      display: grid;
      grid-template-columns: minmax(80px, 120px) 1fr;
      gap: 0.6em;
      font-size: 0.96rem;
      color: var(--text);
    }
    .flashcard-tense li span:first-child {
      font-weight: 600;
      color: #1f2937;
    }
    .flashcard-empty {
      margin: 0;
      text-align: center;
      color: var(--muted);
      font-weight: 500;
    }
    .flashcard-nav {
      display: flex;
      align-items: center;
      justify-content: space-between;
      gap: 1em;
      margin-top: 1.6em;
    }
    .nav-button {
      padding: 0.65em 1.4em;
      border-radius: 10px;
      border: none;
      font-weight: 600;
      font-size: 0.96rem;
      color: #fff;
      background: linear-gradient(135deg, var(--accent) 0%, var(--accent-strong) 100%);
      cursor: pointer;
      box-shadow: 0 6px 16px rgba(37, 99, 235, 0.25);
      transition: transform 0.2s ease, box-shadow 0.2s ease;
    }
    .nav-button:hover:not(:disabled) {
      transform: translateY(-2px);
      box-shadow: 0 10px 24px rgba(37, 99, 235, 0.32);
    }
    .nav-button:disabled {
      opacity: 0.4;
      cursor: not-allowed;
      box-shadow: none;
    }
    .flashcard-counter {
      font-weight: 600;
      color: var(--muted);
      font-size: 0.95rem;
      min-width: 130px;
      text-align: center;
    }

    .flashcard-section {
      margin-top: 3.5em;
      background: var(--card);
      border: 1px solid var(--border);
      border-radius: 20px;
      padding: 2.4em 2.8em;
      box-shadow: 0 14px 36px rgba(15, 23, 42, 0.08);
    }
    .flashcard-section h2 {
      margin: 0 0 0.6em;
      text-align: center;
      font-size: 1.9rem;
      color: var(--accent-strong);
    }
    .flashcard-section p {
      text-align: center;
      color: var(--muted);
      margin: 0.4em 0 1.4em;
    }

    footer {
      text-align: center;
      padding: 1.5em 1em 2.5em;
      color: #6b7280;
      font-size: 0.95rem;
    }

    @media (max-width: 640px) {
      h1 {
        font-size: 2.2rem;
      }
      header p {
        font-size: 0.95rem;
      }
      .section-intro {
        padding: 1.9em 1.8em;
      }
      .grammar-card,
      .conjugation-card {
        padding: 1.6em 1.6em;
      }
      table {
        min-width: 100%;
        font-size: 0.9rem;
      }
      .btn {
        width: 100%;
        justify-content: center;
      }
      .flashcard-controls {
        padding: 1.1em 1.2em;
      }
      .flashcard-tense li {
        grid-template-columns: 1fr;
      }
      .flashcard-tense li span:first-child {
        color: var(--accent-strong);
      }
      .flashcard-nav {
        flex-direction: column;
      }
      .flashcard-counter {
        min-width: auto;
      }
    }

    /* Optimisations supplémentaires pour petits mobiles */
    @media (max-width: 640px) {
      h1 {
        font-size: 2rem;
      }
      header p {
        font-size: 0.9rem;
        padding: 0 8px;
      }
      .section-intro {
        padding: 1.6em 1.4em;
      }
      .grammar-card,
      .conjugation-card {
        padding: 1.4em 1.4em;
      }
      table {
        font-size: 0.85rem;
      }
      table th,
      table td {
        padding: 0.6em 0.5em;
      }
      .btn {
        padding: 1em 1.4em;
        font-size: 0.95rem;
      }
    }

    /* Print stylesheet */
    @media print {
      body {
        background: white;
        color: black;
        font-size: 11pt;
      }
      header, .nav-buttons, .btn, .back {
        display: none !important;
      }
      .section-intro {
        background: none;
        box-shadow: none;
        border: 1px solid #ddd;
        page-break-inside: avoid;
        margin: 1em 0;
        padding: 1em;
      }
      h2 {
        color: black;
        font-size: 14pt;
        margin: 0.5em 0;
      }
      h3 {
        font-size: 12pt;
        page-break-after: avoid;
      }
      table {
        width: 100%;
        border-collapse: collapse;
        page-break-inside: avoid;
        font-size: 9pt;
      }
      table th, table td {
        border: 1px solid #999;
        padding: 4px 6px;
      }
      a {
        color: black;
        text-decoration: none;
      }
    }