<!DOCTYPE html>
<title>getComputedStyle on sibling of style-dirty container</title>
<link rel="help" href="https://drafts.csswg.org/css-contain-3/#size-container">
<link rel="help" href="https://crbug.com/1306385">
<div id=ancestor style="--x:foo">
  <div id=container style="container-type:size;width:100px;">
    <span>Test</span>
  </div>
  <div id=target></div>
</div>
<script>
  ancestor.offsetTop;
  ancestor.style.setProperty('--x', 'bar');
  container.style.width = '200px';
  getComputedStyle(target).getPropertyValue('--x');
</script>
