<!DOCTYPE html>
<html class="reftest-wait">
<!-- Test: if button is disabled, it is barred from constraint validation
and should not be affected by :valid pseudo-class. -->
<link rel='stylesheet' type='text/css' href='style.css'>
<body onload="document.getElementById('b').disabled='true'; document.documentElement.className='';">
<button class='notvalid' id='b'></button>
</body>
</html>