:root{
  --bg:#0b0d12;
  --card:#131826;
  --muted:#a6b0bf;
  --text:#e7eef7;
  --border:rgba(255,255,255,.10);
  --shadow: 0 16px 30px rgba(0,0,0,.35);
  --accent:#7c3aed;
  --accent2:#06b6d4;
}
*{box-sizing:border-box}
body{
  margin:0;
  min-height:100vh;
  background: radial-gradient(900px 520px at 20% 20%, rgba(124,58,237,.18), transparent 60%),
              radial-gradient(900px 520px at 85% 20%, rgba(6,182,212,.14), transparent 55%),
              var(--bg);
  color:var(--text);
  font-family: system-ui, -apple-system, Segoe UI, Roboto, Arial;
}
.wrap{width:min(1100px, calc(100% - 24px)); margin:0 auto; padding:16px}
.top{display:flex; justify-content:space-between; align-items:flex-end; gap:14px; flex-wrap:wrap}
h1{margin:0 0 6px 0; font-size:28px}
.muted{color:var(--muted)}
.card{
  margin-top:14px;
  background:rgba(19,24,38,.92);
  border:1px solid var(--border);
  border-radius:18px;
  padding:16px;
  box-shadow: var(--shadow);
}
.hud{display:flex; gap:10px; align-items:center; flex-wrap:wrap}
.chip{
  background:rgba(255,255,255,.06);
  border:1px solid var(--border);
  border-radius:999px;
  padding:8px 10px;
  font-weight:800;
}
.btn{
  cursor:pointer;
  border:1px solid rgba(124,58,237,.35);
  background:rgba(124,58,237,.16);
  color:var(--text);
  border-radius:12px;
  padding:9px 12px;
  font-weight:900;
}
.btn:hover{filter:brightness(1.04)}
.board{
  display:grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap:12px;
}
@media (max-width: 520px){
  .board{grid-template-columns: repeat(3, minmax(0, 1fr));}
}
.cardbtn{
  position:relative;
  aspect-ratio: 1 / 1;
  border-radius:16px;
  border:1px solid rgba(255,255,255,.12);
  background:rgba(255,255,255,.05);
  cursor:pointer;
  overflow:hidden;
}
.cardbtn:focus{outline:3px solid rgba(6,182,212,.35); outline-offset:2px}
.cardbtn .face,
.cardbtn .back{
  position:absolute;
  inset:0;
  display:flex;
  align-items:center;
  justify-content:center;
  font-size:44px;
  transition: transform .18s ease;
}
.cardbtn .back{
  background: linear-gradient(180deg, rgba(124,58,237,.28), rgba(6,182,212,.18));
  font-weight:1000;
}
.cardbtn .face{transform: rotateY(180deg);}
.cardbtn.is-open .back{transform: rotateY(180deg);}
.cardbtn.is-open .face{transform: rotateY(0deg);}
.cardbtn.is-matched{opacity:.55; cursor:default}
.msg{min-height:26px; margin-top:12px; font-weight:1000}
.msg.ok{color:#34d399}