<!doctype html>
<html>
<head>
<meta charset="utf-8">
<script>
document.addEventListener("DOMContentLoaded", () => {
  document.execCommand("selectAll");
  document.querySelector("li").addEventListener("DOMSubtreeModified", () => {
    document.designMode = "on";
    document.execCommand("justifyCenter");
    getSelection().deleteFromDocument();
  });
  document.querySelector("li").type = "1";
});
</script>
</head>
<body>
<li>
  <h3 align="right">
    <option contenteditable="true"></option>
  </h3>
</li>
</body>
</html>
