A beta logo for tablet viewports and above

The beta logo is displayed on tablet viewports,

![beta-logo](https://f.cloud.github.com/assets/84996/850257/0fd9636a-f484-11e2-8e6c-afd42632c77e.png)

And it disappears on smaller viewports,

![beta-small](https://f.cloud.github.com/assets/84996/850258/11bacbb0-f484-11e2-9f81-66ce0c4907f6.png)