jumping logo in mobile view

I’ve just created my first wordpress page with the fantastic customizr theme.
One issue I couldn’t resolve, is that in mobile view, the logo is centered and the collapsed menu button is one line beneath on the right when I load the page.
On scrolling down, the logo jumps to the left and the collapsed menu button jumps to the same line as the logo. That’s exactly I want the page to look when it is loaded resp. scrolled to the top, but endless css modifications haven’t resolved the issue yet.
the url is http://www.metallico.at

I’d appreciate your help / hints.

thx, Ben