HTML Code

<!DOCTYPE html>
<html lang="en">
<head>
  <meta charset="utf-8">
  <title>style sheet sets report</title>
</head>
<body>
  <pre id="out"></pre>
  <script>
    function reportStyleSheetSets() {
      if (!("preferredStyleSheetSet" in document)) {
        return "Style sheet set API not supported";
      }
      return JSON.stringify({
        preferred: document.preferredStyleSheetSet,
        selected: document.selectedStyleSheetSet,
        last: document.lastStyleSheetSet
      }, null, 2);
    }
    document.getElementById("out").textContent = reportStyleSheetSets();
  </script>
</body>
</html>

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