wm-propagation-body-contain-root.html

<!doctype html>
<meta charset="utf-8">
<title>CSS Writing Modes Test: Do not propagate writing-mode from body when html root is contained</title>
<link rel="help" href="https://drafts.csswg.org/css-writing-modes/#principal-flow">
<link rel="match" href="wm-propagation-body-contain-root-ref.html">
<style>
  html { contain: paint; }
  body { writing-mode: vertical-rl; }
</style>
<body>This text should run vertically on the left side</body>

chromium/third_party/blink/web_tests/external/wpt/css/css-writing-modes/wm-propagation-body-contain-root.html