<!DOCTYPE html> <html class="reftest-wait"> <!-- Test: if input is no longer readonly, it is candidate for constraint validation and should be affected by :invalid pseudo-class. --> <link rel='stylesheet' type='text/css' href='style.css'> <body onload="document.getElementById('i').removeAttribute('readonly'); document.documentElement.className='';"> <input class='invalid' id='i' readonly required> </body> </html>