<!DOCTYPE html>
<html>
  <head>
    <meta charset="utf-8">
    <title>CSS Masking: mask-image: data url mask</title>
    <link rel="author" title="CJ Ku" href="mailto:cku@mozilla.com">
    <link rel="author" title="Mozilla" href="https://www.mozilla.org">
    <style type="text/css">
      div {
        background-color: purple;
        width: 50px;
        height: 50px;
      }
    </style>
  </head>
  <body>
    <div/>
  </body>
</html>
