#test01, #test02, #test03{
        width: 50px;
        height: 50px;
        text-align:center;
        font-size: 20px;
      }
      #test{
        background: #ff0000;
      }
      #test01{
        background: #7FFF00;
      }
      #test02{
        background: #00FFFF;
      }
      #test03{
        background: #4169E1;
      }