Fix tabs design for tablets/mobile

- [x] Fix on Tablets
- [x] Fix on Mobile

It closes #308.

**Tablets**
![screen shot 2014-06-12 at 3 44 59 pm](https://cloud.githubusercontent.com/assets/230476/3259186/430bd2fc-f241-11e3-9709-c96ff2abc0ea.png)