Make width a percentage instead of hard coded

This is obviously very subjective but relative width pages are more idiomatic.  And I think they're easier to read YMMV :)

###Before:
![screenshot 2014-08-23 at 4 34 07 pm](https://cloud.githubusercontent.com/assets/1702745/4021793/dfdfba02-2b04-11e4-957e-a1d049681c8e.png)

###After:
![screenshot 2014-08-23 at 4 32 45 pm](https://cloud.githubusercontent.com/assets/1702745/4021788/cbb9e53e-2b04-11e4-9a45-6643ae672579.png)