table {
      text-align: center;
      border-collapse: collapse;
    }

    td {
      width: 50px;
      height: 50px;
      border: 1px solid black;
    }
     tr:nth-child(odd) 
     {
      background-color: black;
      color: white;
    }
    td:nth-child(even) {
         background-color: black;
      color: white;
    }
    td:nth-child(odd){
        background-color: black;
      color: white;
    }
    tr:nth-child(even) {
        background-color: black;
      color: white;

    }