Updated CSS files and a little design

I noticed that the CSS needed a bit of love, so I rearchitected the files, removing Bootstrap and adding a Normalize file. I also cleaned up some of the design, adding some white space, letting the typography and layout breath a little bit. 

Overall, these changes set us up for quicker design updates in the future, as well as freshen up the visuals a bit.

I think there's a lot more to do, especially at a higher level, but hoping to get in incremental changes.