The only reason is to make &lt;header&gt;'s height not less than QR image (possible issue is on the picture above: QR image is overlapped with dotted line). 

I couldn't find any solution for now other than add &lt;div&gt; with "clear: left" into the last place inside of the &lt;header&gt; due to QR image's &lt;div&gt; uses "float: left".