<!DOCTYPE HTML>
<title>Reference: The nested empty span should be skipped when finding the ::first-letter content</title>
<link rel="author" title="Jaeyong Bae" href="jdragon.bae@gmail.com">
<style>
first-letter { color: green }
</style>
<div>
  <span><first-letter>F</first-letter>irst letter should be green</span>
</div>