Buttons on mobile are hard to click on

Solve a part of #3847 

> *"The image of the buttons are bigger than the actual `<a>` element that's clickeable."*

# Before

![](https://f.cloud.github.com/assets/1857707/64252/358e0264-5e39-11e2-98cd-1655e8140546.png)
Via issues #3847

# After

![Pantallazo](https://f.cloud.github.com/assets/1108789/142124/996706c4-72c4-11e2-8792-e8fc602216e5.png)