<!doctype html>
<html lang=en>
  <meta charset=utf-8>
  <title>CSS-contain test reference</title>
  <link rel="author" title="Florian Rivoal" href="https://florian.rivoal.net">

<style>
div { overflow: hidden; }
rt {
  display: -webkit-ruby-text;
  font-size: 1rem;
}
</style>

<p>This test passes if you can see the word PASS below.
<div><ruby><rt>PASS</rt></ruby></div>