lang-vs-xml-lang.html | Explore in Territory

<html>
 <title>':lang()': inherit LANG from parent element, xml:lang is ignored in HTML</title>
 <style>
  p:lang(x) { background: red }
  p:lang(y) { background: blue }
  p:lang(z) { background: green }
 </style>
 <div xml:lang="x-test" lang="z-test">
    <p>This line should have a green background.</p>
    <p lang="y-test">This line should NOT have a green background.</p>
 </div>
</html>

chromium/third_party/blink/web_tests/fast/selectors/lang-vs-xml-lang.html