   <style type="text/css">
      div {
        background-color: purple;
        width: 100px;
        height: 100px;
      }

      div.mask-by-svg-mask {
        mask-image: url(support/mask-half-transparent-100x100.svg#mask);
      }
    </style>
  </head>
  <body>
    <div class="mask-by-svg-mask"></div>
  </body>
</html>
