<style>
* {
  border-block-start: 4px solid;
  -webkit-line-grid: simple;
  transition: border-width 100ms linear;
  column-width: 1000px;
  cursor: auto;
  padding-top: 10000000000px;
}
*::after {
  content: 'a'
}
</style>
PASS if no crash or assert.
<script>
if (window.testRunner)
  testRunner.dumpAsText()
</script>