<!doctype html>
<html class="test-wait">
<head>
<meta charset="utf-8">
<script>
try {
  function onDOMNodeInsertedOfContentEditable() {
    getSelection().collapse(document.querySelector("input"));
    document.execCommand("justifyCenter");
    document.querySelector("dl").addEventListener("DOMSubtreeModified", onDOMSubtreeModifiedOfDLElement);
    document.querySelector("dl").appendChild(document.querySelector("style"));
  }
  function onDOMSubtreeModifiedOfDLElement() {
    document.execCommand("delete");
    document.querySelector("label").appendChild(document.querySelector("input"));
    document.querySelector("dd[contenteditable]").addEventListener("DOMNodeInserted", onDOMNodeInsertedOfContentEditable);
  }
  addEventListener("load", () => {
    onDOMNodeInsertedOfContentEditable();
    document.documentElement.removeAttribute("class");
  });
} catch (ex) {
  // maybe too many recursive exception would be thrown.
  document.documentElement.removeAttribute("class");
}
</script>
</head>
<body><label></label>
<dl>
<dd contenteditable>
<style>@</style>
<input>
</body>
</html>