<!DOCTYPE html> <html> <head> <title>CSS Shadow Parts - Host Stylesheet</title> <meta href="mailto:fergal@chromium.org" rel="author" title="Fergal Daly"> <link href="http://www.google.com/" rel="author" title="Google"> <link href="https://drafts.csswg.org/css-shadow-parts/" rel="help"> <script src="/resources/testharness.js"></script> <script src="/resources/testharnessreport.js"></script> <script src="support/shadow-helper.js"></script> </head> <body> <script>installCustomElement("custom-element", "custom-element-template");</script> <template id="custom-element-template"> <style> ::part(partp) { color: red; } span { color: green; } </style> <span id="part" part="partp">This text</span> </template> The following text should be green: <custom-element id="c-e"></custom-element> <script> "use strict"; const colorGreen = "rgb(0, 128, 0)"; test(function() { const el = getElementByShadowIds(document, ["c-e", "part"]); assert_equals(window.getComputedStyle(el).color, colorGreen); }, "Part in selected host is not styled by ::part in a stylesheet inside the host"); </script> </body> </html>