Make minor design improvements

| | before | after |
|:---:|:---:|:---:|
| Live example| [click me!](http://html5boilerplate.com/) | [click me!](http://alrra.github.io/h5bp-docs/) |
| Screenshot | <img src="https://cloud.githubusercontent.com/assets/1223565/2769186/279332b0-ca4e-11e3-9f51-1435185da1f1.png" width=200 height=400> | <img src="https://cloud.githubusercontent.com/assets/1223565/2769176/0536380c-ca4e-11e3-8c85-0065661cf6ce.png" width=200 height=500> |

Cc: @drublic