@media(max-width: 768px) {
  .board {
    width: 360px;
    height: 360px;
    gap: 6px;
  }

  .cell {
    width: 110px;
    height: 110px;
    font-size: 30px;
  }
}
@media(max-width: 480px) {
  .board {
    width: 300px;
    height: 300px;
    gap: 5px;
  }

  .cell {
    width: 95px;
    height: 95px;
    font-size: 26px;
  }
}

@media(max-width: 320px) {
  .board {
    width: 270px;
    height: 270px;
    gap: 4px;
  }

  .cell {
    width: 85px;
    height: 85px;
    font-size: 22px;
  }
}