Allow content to get on top of the navigation

Fixes #5383

## Before

![screen shot 2014-08-06 at 12 18 08](https://cloud.githubusercontent.com/assets/85783/3825984/6417a80a-1d5b-11e4-8203-1a3d024a9d77.PNG)


## After

![screen shot 2014-08-06 at 12 17 48](https://cloud.githubusercontent.com/assets/85783/3825987/668be2ea-1d5b-11e4-8aa1-8f05a2bb872b.PNG)

![ ](http://gifs.joelglovier.com/eddie-izzard/eddie-izzard-shaking-head.gif)