<!DOCTYPE html>
<html>
    <head>
        <title>Columns, then column-span:all</title>
    </head>
    <body>
        <p>You should see the word 'PASS' twice below (letter spacing will differ), and no red:</p>
        <div style="-webkit-columns:4; columns:4; -webkit-column-gap:0; column-gap:0; width:4em;">
            P<br>A<br>S<br>S
            <div style="background:red;">
                <div style="-webkit-column-span:all; column-span:all;">PASS<br>&nbsp;</div>
            </div>
        </div>
    </body>
</html>