eat: no-repeat;
        float: left;
        width: 20px;
        height: 20px;
      }

      .op_y-7  { background-position: 50%  -7% }
      .op_y13  { background-position: 50%  13% }
      .op_y23  { background-position: 50%  23% }
      .op_y50  { background-position: 50%  50% }
      .op_y75  { background-position: 50%  75% }
      .op_y88  { background-position: 50%  88% }
      .op_y111 { background-position: 50% 111% }

    </style>
  </head>
  <body>
    <div class="op_y-7"></div>
    <div class="