body {
    display: flex;
    justify-content: center;
    align-items: center;
    height: 100vh;
    margin: 0;
  }
  
  .board {
    display: grid;
    grid-template-columns: repeat(3, 100px);
    grid-gap: 0px;
    border: 7px solid #000;
  }
  
  .cell {
    width: 100px;
    height: 100px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    cursor: pointer;
    border: 2px solid #000;
  }

  .header { 
    width: 50px; 
    height: 50px;
    display: flex;
    align-items: center;
    justify-content: center;
    font-size: 24px;
    

}