.board-3x3 {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0.5rem;
  max-width: min(400px, 100%);
  margin: 0 auto;
}

.cell {
  aspect-ratio: 1;
  min-height: 44px;
  background-color: var(--surface);
  border-radius: var(--border-radius);
  display: flex;
  justify-content: center;
  align-items: center;
  font-size: 3rem;
  cursor: pointer;
  touch-action: manipulation;
  user-select: none;
  transition: all 0.2s ease;
  box-shadow: inset 0 2px 4px rgba(0,0,0,0.2);
}

.cell:hover:not(.taken) {
  background-color: var(--surface-light);
  transform: scale(1.05);
}

.cell.taken {
  cursor: default;
}

.cell.x { color: var(--primary); }
.cell.o { color: var(--secondary); }

.cell.winning {
  animation: pulse 0.6s ease-in-out infinite alternate;
  background-color: rgba(16, 185, 129, 0.2);
}

@keyframes pulse {
  from { transform: scale(1); box-shadow: 0 0 0px var(--accent), inset 0 0 10px var(--accent); }
  to { transform: scale(1.1); box-shadow: 0 0 15px var(--accent), inset 0 0 20px var(--accent); }
}

@media (max-width: 600px) {
  .cell {
    width: auto;
    min-height: 0;
    font-size: 2.2rem;
  }
}