<html><head><style>input:read-only { background-color: yellow;}</style></head><body><h1>Demo of the :read-only selector</h1><p>The :read-only selector selects form elements with a "readonly" attribute:</p><p>A normal input element:<br><input value="hello"></p><p>A readonly input element:<br><input readonly value="hello"></p></body></html>