<!DOCTYPE html> <meta charset="utf-8"> <title>CSS Test: Dynamic attribute change handling in generated content</title> <link rel="author" title="Emilio Cobos Álvarez" href="mailto:emilio@crisal.io"> <link rel="help" href="https://drafts.csswg.org/css-variables/#using-variables"> <link rel="match" href="variable-generated-content-dynamic-001-ref.html"> <style> :root { --my-attr: attr(data-foo); } div::before { content: var(--my-attr); } </style> <div data-foo="FAIL"></div> <script> document.body.offsetTop; document.querySelector('div').setAttribute('data-foo', "PASS"); </script>