css/css-display/display-contents-first-line-001.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS Display: display:contents and ::first-line</title>
<link rel="author" title="Rune Lillesveen" href="mailto:rune@opera.com">
<link rel="help" href="https://drafts.csswg.org/css-display-3/#valdef-display-contents">
<link rel="help" href="https://drafts.csswg.org/css-pseudo-4/#first-line-pseudo">
<link rel="match" href="display-contents-pass-green-no-red-ref.html">
<style>
    #contents { display: contents }
    #contents::first-line { background-color: red }
    #container::first-line { color: green }
</style>
<p>You should see the word PASS in green and no red below.</p>
<div id="container">
    <div id="contents"><span>P</span>ASS</div>
</div>