Customizing slimmenu w/ logo or header

[nickpish]

I'm trying to customize the behavior/appearance of slimmenu to accommodate a logo or header floated at the left of a container with the main navigation floated to the right, as I've described here: http://stackoverflow.com/questions/19062327/designing-a-collapsible-responsive-navigation-bar. I also have a jsFiddle work-in-progress here: http://jsfiddle.net/nickpish/Nmh9Z/18/

Ultimately, I'd like to place the main navigation at right, but make the collapsed/mobile menu display the nav items at 100% width beneath the logo/header when activated at the breakpoint, I'm struggling with the appropriate CSS to achieve this layout-- any suggestions are most appreciated.