<!doctype html>
<div id="contents" style="display: contents; color: green; border: 10px solid red;">
  <div>
    Passes if the text is green and there's no border.
  </div>
</div>
<script>
document.body.offsetTop;

let contents = document.getElementById("contents");

contents.style.color = "red";
document.body.offsetTop;
contents.style.color = "green";
</script>