.iso-board {
  display: grid;
  grid-template-columns: repeat(7, 1fr);
  gap: 3px;
  width: min(92vw, 360px);
  margin: 12px auto;
  aspect-ratio: 1 / 1;
}
.iso-cell {
  border-radius: 6px;
  background: var(--card);
  display: flex; align-items: center; justify-content: center;
  font-size: 22px; cursor: pointer;
  border: 2px solid transparent;
}
.iso-cell.wall { background: #3a3f4b; cursor: default; }
.iso-cell.p1 { background: #ff6b6b; color: #fff; }
.iso-cell.p2 { background: #4d96ff; color: #fff; }
.iso-cell.sel { border-color: #ffd93d; }