css/css-pseudo/first-letter-and-sibling-display-change.html

<!DOCTYPE html>
<title>CSS Test: Changing ::first-letter color while sibling changes display type.</title>
<link rel="author" title="Rune Lillesveen" href="mailto:futhark@chromium.org">
<link rel="match" href="first-letter-block-to-inline-ref.html">
<link rel="help" href="https://drafts.csswg.org/css-pseudo-4/#first-letter-pseudo">
<style>
  div { color: green }
  div::first-letter { color: red }
  .green::first-letter { color: green }
</style>
<div>This text should be green.<span></span></div>
<script>
  document.body.offsetTop;
  document.querySelector("span").style.display = "block";
  document.querySelector("div").className = "green";
</script>