chromium/third_party/blink/web_tests/external/wpt/css/css-page/cssom/dynamic-001-print.html

<!DOCTYPE html>
<link rel="author" title="Morten Stenshorne" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/cssom/#the-csspagerule-interface">
<link rel="help" href="https://drafts.csswg.org/css-page-3/">
<link rel="match" href="dynamic-001-print-ref.html">
<style id="sheet">
  @page { }
  body {
    background: green;
  }
</style>
<script>
  let pageRule = document.getElementById("sheet").sheet.rules[0];
  pageRule.insertRule("@top-center { content:'This text should be seen at the top, and there should be a green square below.'; vertical-align:top; }");
  pageRule.style.setProperty("margin", "50px 0 0");
  pageRule.style.setProperty("border", "solid white");
  pageRule.style.setProperty("border-width", "0 300px");
  pageRule.style.setProperty("width", "100px");
  pageRule.style.setProperty("height", "100px");
</script>