<!doctyle html>
<style>
div { color:green; }
</style>
<div>Test that :is() is invalid if it contains a pseudo element</div>
<div>Test that :is() is invalid if it contains a pseudo element</div>
<div>Test that :where() is invalid if it contains a pseudo element</div>
<div>Test that :where() is invalid if it contains a pseudo element</div>