<!DOCTYPE html>
<style>
  html::before {
    content: '';
  }
  html {
    min-width: 100000px;
  }
  body, div {
    padding-bottom: 50000%;
  }
  div:first-child {
    float: right;
  }
</style>
<!-- PASS if no crash or assert -->
<script>
  if (window.testRunner)
    testRunner.dumpAsText();
  onload = () => {
    let n0 = document.createElement('span');
    document.documentElement.appendChild(n0);
    n0.appendChild(document.createElement('div'));
    document.documentElement.appendChild(document.createElement('div'));
    document.documentElement.appendChild(document.createElement('span'));
    document.body.offsetTop;
    document.styleSheets[0].insertRule(`:first-of-type::first-letter { background: grey; }`);
  };
</script>