:root{
    --bg: #0b1220;
  
    --text: rgba(255,255,255,.92);
    --muted: rgba(255,255,255,.72);
    --muted2: rgba(255,255,255,.58);
  
    --panel: rgba(255,255,255,.06);
    --stroke: rgba(255,255,255,.14);
  
    --shadow: 0 18px 60px rgba(0,0,0,.45);
  }
  
  *{ box-sizing: border-box; }
  
  html, body{ height: 100%; }
  
  body{
    margin: 0;
    font-family: system-ui, -apple-system, "Poppins", Arial, sans-serif;
    color: var(--text);
    background: var(--bg);
    overflow-x: hidden;
  }
  
  /* Fond DA */
  body::before{
    content: "";
    position: fixed;
    inset: 0;
    z-index: -2;
    background:
      radial-gradient(1100px 600px at 18% -10%, rgba(87, 168, 255, .35), transparent 62%),
      radial-gradient(900px 520px at 90% 8%, rgba(180, 106, 255, .28), transparent 58%),
      radial-gradient(900px 600px at 50% 110%, rgba(87, 168, 255, .18), transparent 60%),
      radial-gradient(900px 600px at 0% 110%, rgba(180, 106, 255, .14), transparent 62%);
  }
  
  body::after{
    content: "";
    position: fixed;
    inset: 0;
    z-index: -1;
    background: linear-gradient(to bottom, rgba(0,0,0,.10), rgba(0,0,0,.28));
    pointer-events: none;
  }
  
  .wrap{
    max-width: 1120px;
    margin: 0 auto;
    padding: 0 26px;
  }
  
  /* Header page */
  .page-head{
    padding: 26px 0 10px;
  }
  
  .page-head__top{
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 12px;
  }
  
  .chip{
    display: inline-flex;
    padding: 8px 12px;
    border-radius: 999px;
    background: rgba(255,255,255,.10);
    border: 1px solid var(--stroke);
    color: var(--muted);
    font-size: 13px;
  }
  
  .meta{
    color: var(--muted2);
    font-size: 14px;
  }
  
  .page-title{
    margin: 16px 0 0;
    text-align: center;
    font-size: 22px;
    letter-spacing: 1.2px;
    font-weight: 800;
    color: rgba(255,255,255,.86);
    text-transform: uppercase;
  }
  
  .page-actions{
    margin-top: 12px;
    display: flex;
    justify-content: center;
  }
  
  .btn{
    display: inline-flex;
    text-decoration: none;
    color: var(--text);
    padding: 10px 13px;
    border-radius: 12px;
    background: rgba(255,255,255,.12);
    border: 1px solid var(--stroke);
    transition: transform .15s ease, background .15s ease, border-color .15s ease;
  }
  
  .btn:hover{
    transform: translateY(-1px);
    background: rgba(255,255,255,.16);
    border-color: rgba(255,255,255,.22);
  }
  
  /* Bloc exercice */
  .exo-card{
    margin: 18px 0 22px;
    background: rgba(255,255,255,.06);
    border: 1px solid rgba(255,255,255,.14);
    border-radius: 8px;
    box-shadow: var(--shadow);
    overflow: hidden;
  }
  
  .exo-title{
    margin: 0;
    padding: 14px 16px;
    font-size: 14px;
    letter-spacing: .7px;
    text-transform: uppercase;
    color: rgba(255,255,255,.86);
    background: rgba(255,255,255,.04);
    border-bottom: 1px solid rgba(255,255,255,.12);
  }
  
  .exo-view{
    padding: 12px 12px 0;
    background: rgba(0,0,0,.10);
  }
  
  .exo-iframe{
    width: 100%;
    height: 640px;
    border: 0;
    background: #fff;
    border-radius: 6px;
  }
  
  .exo-comment{
    margin: 12px;
    padding: 14px;
    background: rgba(255,255,255,.06);
    border: 1px solid rgba(255,255,255,.14);
    border-radius: 6px;
  }
  
  .exo-comment__title{
    margin: 0 0 8px;
    font-size: 13px;
    letter-spacing: .4px;
    text-transform: uppercase;
    color: rgba(255,255,255,.82);
  }
  
  .exo-comment p{
    margin: 0 0 10px;
    color: rgba(255,255,255,.72);
    font-size: 14px;
    line-height: 1.7;
  }
  
  .exo-comment p:last-child{
    margin-bottom: 0;
  }
  
  /* Footer */
  .page-footer{
    padding: 18px 0 26px;
    text-align: center;
    color: var(--muted2);
    font-size: 13px;
  }
  
  .page-footer p{
    margin: 0;
  }