Source code

Revision control

Other Tools

Test Info:

<!DOCTYPE html>↩
<html>↩
<head>↩
<script type="text/javascript">↩
function boom()↩
{↩
document.documentElement.style.columnCount = '3';↩
document.documentElement.offsetHeight;↩
document.documentElement.style.columnCount = '';↩
}↩
</script>↩
<style type="text/css">↩
html:before { content: '0'; }↩
</style>↩
</head>↩
<frameset onload="boom();"></frameset>↩
</html>↩