Update h3 style and alignment

Just a suggestion here to add some visual separation in the content.

I couldn't tell if `page.css` or `page.scss` was the correct source to update for this repo, so I just manually updated both. :boy: :v:

### Le before

![h3-styles-before](https://f.cloud.github.com/assets/32535/250611/76288158-8b4f-11e2-8723-770a5feaaec7.png)

### Le after

![h3-styles-after](https://f.cloud.github.com/assets/32535/250607/5dc3cd02-8b4f-11e2-99d4-07fde642241b.png)