: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);
  --panel2: rgba(255,255,255,.08);
  --stroke: rgba(255,255,255,.14);

  --radius: 18px;
  --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;
}

/* En-tête 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);
}

/* Carte exercice (comme la capture : un gros bloc blanc mais en dark glass) */
.exo-card{
  margin: 18px 0 22px;
  background: rgba(255,255,255,.06);
  border: 1px solid rgba(255,255,255,.14);
  border-radius: 8px; /* la capture est plus “rectangle” que “pillow” */
  box-shadow: var(--shadow);
  overflow: hidden;
}

/* Titre exercice (barre du haut) */
.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);
}

/* Viewer grand format */
.exo-view{
  padding: 12px 12px 0;
  background: rgba(0,0,0,.10);
}

.exo-iframe{
  width: 100%;
  height: 640px; /* gros rendu, proche de ta capture */
  border: 0;
  background: #fff;
  border-radius: 6px;
}

/* Commentaire (bloc type “encadré beige” mais version dark) */
.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;
}