<!DOCTYPE html>
<html class="reftest-wait reftest-no-flush">
<title>
Transform animation creates a stacking context when changing its display style
</title>
<style>
span {
  height: 100px;
  width: 100px;
  position: fixed;
  background: green;
  top: 50px;
}
div {
  width: 100px; height: 100px;
  background: blue;
  display: none;
}
</style>
<span></span>
<div id="test"></div>
<script>
  var anim = document.getElementById("test")
    .animate({ transform: ['none', 'none'] }, { duration: 100000 });
  anim.ready.then(function() {
    anim.effect.target.style.display = 'block';
    document.documentElement.classList.remove("reftest-wait");
  });
</script>