chromium/third_party/blink/web_tests/external/wpt/css/selectors/selectors-4/lang-023.html

<!DOCTYPE html>
<html lang="en-US">
<meta charset="utf-8">
<title>CSS Selectors 4 - :lang matching</title>
<link rel="author" title="Jonathan Kew" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/selectors-4/#the-lang-pseudo">
<link rel="match" href="lang-000-ref.html">

<style>
div.test { color: red; }
:lang("x") { color: green; } /* not a well-formed lang tag, but matches per
                                the Extended Filtering algorithm */
</style>

<div class="test"><span lang="x-lojban">This should be green</span></div>