[Theme: Growler] Responsive problems

Hey everyone! I have some serious trouble with my responsive design.
When I open my site on an iphone (for example) the page background / footer wont stretch over the whole length of the site. I’m very grateful if someone takes a look at it and could tell me whats the problem there.

http://www.baracca.ch
or:
http://responsivetest.net/#u=baracca.ch|640|1136|2

Thank you!:)