body {
  font-family: Arial, sans-serif;
  text-align: center;
  background: #f5f5f5;
  color: #333;
}

.board {
  display: grid;
  grid-template-columns: repeat(3, 100px);
  grid-gap: 5px;
  margin: 20px auto;
  width: max-content;
}

.cell {
  width: 100px;
  height: 100px;
  background: white;
  border: 2px solid #0ea5a0;
  font-size: 2.5rem;
  display: flex;
  align-items: center;
  justify-content: center;
  cursor: pointer;
}

.cell.taken {
  cursor: not-allowed;
  background: #eee;
}