Reduce padding and font-size to use more of the screen

The slash in the system path was large, and the right/left padding of
the whole page used a lot of whitespace on smaller screens. Reducing the
font-size and the padding gives more space for Marathon tasks.

**Before:**
![screen shot 2013-10-17 at 1 43 03 pm](https://f.cloud.github.com/assets/29612/1355829/7c094966-376d-11e3-81f4-890bc960edeb.png)

**After:**
![screen shot 2013-10-17 at 1 43 31 pm](https://f.cloud.github.com/assets/29612/1355831/7fcfd402-376d-11e3-942e-c69073a23f25.png)