html, body {
    background-color: #FAFAFA
  }
  
  .sudoku_parent table {
    border: 2px solid #000000;
  }
  
  .sudoku_tr td {
    border: 1px solid #000000;
    text-align: center;
    vertical-align: middle;  
  }
  
  .sudoku_tr input {
    color: #000000;
    padding: 0;
    border: 0;
    text-align: center;
    width: 48px;
    height: 48px;
    font-size: 24px;
    background-color: #FFFFFF;
    outline: none;
  }
  
  .sudoku_tr input:disabled {
    background-color: #EEEEEE;
  }
  
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  #cell-2,  #cell-11, #cell-20 { border-right:  2px solid #000000; }
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  #cell-45, #cell-46, #cell-47 { border-bottom: 2px solid #000000; }
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  #cell-48, #cell-49, #cell-50 { border-bottom: 2px solid #000000; }
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  #cell-75, #cell-76, #cell-77 { border-bottom: 2px solid #000000; }
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  #cell-60, #cell-69, #cell-78 { border-left:   2px solid #000000; }