.main-pitch cosmetic overhaul

Alright, this appears hacky, but it's fairly precise -- we want
.main-pitch to have essentially the page's width yet we want it
inside the limited-width .page-content.

Will need to reorganize a lot of the styling soon...

![screenshot from 2013-07-24 23 22 27](https://f.cloud.github.com/assets/2473115/853551/55bd8e34-f4e2-11e2-84d8-d61fd22f25ca.png)