<html xmlns="http://www.w3.org/1999/xhtml" class="reftest-wait">

<style id="sty">
html::before { 
  content: "before text"; 
  float: right; 
}
</style>

<script>
function boom()
{ 
  var sty = document.getElementById("sty"); 
  sty.appendChild(document.createTextNode(" "));
  document.documentElement.removeAttribute("class");
}
  
setTimeout(boom, 30);
</script>

</html>