<!DOCTYPE html> <html class="reftest-wait"> <head> <style type="text/css"> div { height: 20px; width: 100%; background-color: blue; vertical-align: bottom; } #block1 { margin-bottom: 15px; } #inline-block1 { margin: 25px 0 25px; } #inline-block2 { margin: 15px 0 15px; } #block2 { margin-top: 25px; } </style> <script type="text/javascript"> function test() { document.getElementById('inline-block1').style.display = 'inline-block'; document.getElementById('inline-block2').style.display = 'inline-block'; document.documentElement.removeAttribute('class'); } document.addEventListener('MozReftestInvalidate', test, false); </script> </head> <body> <div id="block1"></div> <div id="inline-block1"></div> <div id="inline-block2"></div> <div id="block2"></div> </body> </html>