A CodePen by Laidlaw. cssPanelMenu - Based on http://jpanelmenu.com/
css solution: http://codepen.io/Jenn/pen/tIFaH
back button fix: http://codepen.io/jetpacmonkey/pen/ktIJz

This is a beautiful solution and because it has no javascript, it works much more smoothly on mobile. There are only a few caveats.
You can't just plug it in, it relies on a certain structure. The class .main-nav and the id #main-nav can be called whatever you like, but they must be the outermost element of the navigation or the whole thing falls apart.

When the menu opens, the content doesn't really slide over, it gets smushed and often doesn't look very good. To take the focus off that effect, transition the opacity of the content while the menu is open. It's simple and looks cool.

The final problem is not something you'd would notice in Codepen because Codepen doesn't (as far as I know) show changes in the url. The back button is rendered useless because the menu button updates the url. yuck. (Compiled from sean Shaw's research).

http://codepen.io/jetpacmonkey/pen/ktIJz solves it.