<!-- Any copyright is dedicated to the Public Domain.
     http://creativecommons.org/publicdomain/zero/1.0/ -->
<html style="--COLOR: green; --background: black">
<head>

  <style>
    div {
      background: var(--background);
      color: var(--COLOR);
    }
  </style>
</head>
<body>
  <div id="target">test</div>
</body>
</html>
