.gm-board {
  display: grid;
  grid-template-columns: repeat(9, 1fr);
  width: min(92vw, 360px);
  aspect-ratio: 1 / 1;
  background: #0f1b2d;
  border: 3px solid #2b3f5c;
  border-radius: 10px;
  padding: 3px;
  gap: 1px;
  touch-action: none;
}
.gm-cell { background: #16263c; border-radius: 2px; position: relative; }
.gm-cell.wall { background: #2b3f5c; }
.gm-cell.goal { background: #1d3a26; }
.gm-cell.goal::after {
  content: "🎯"; position: absolute; inset: 0;
  display: grid; place-items: center; font-size: 18px;
}
.gm-cell.ball::after {
  content: ""; position: absolute; inset: 22%;
  background: #4d96ff; border-radius: 50%;
  box-shadow: 0 0 8px #4d96ff;
}