css/css-scoping/shadow-root-insert-into-document.html

<!doctype html>
<title>CSS Scoping Module Level 1 - Dynamic insertion of shadow host</title>
<link rel="author" href="mailto:emilio@crisal.io">
<link rel="help" href="https://drafts.csswg.org/css-scoping/#selectors-data-model">
<link rel="match" href="reference/green-box.html"/>
<p>Test passes if you see a single 100px by 100px green box below.</p>
<script>
  let host = document.createElement('div');
  let root = host.attachShadow({ mode: 'open' });
  root.innerHTML = `
    <style>
      div { background: green; width: 100px; height: 100px; }
    </style>
    <div></div>
  `;
  document.body.offsetTop;
  document.body.appendChild(host);
</script>