Workbook style tuneup

Cleans up and adjusts some appearance issues that were introduced in the custom Workbook layout and stylesheet.

![screen shot 2014-04-27 at 5 24 01 pm](https://cloud.githubusercontent.com/assets/352082/2812727/71f64cfe-ce6b-11e3-8028-0e97fc84bdb1.png)
![screen shot 2014-04-27 at 5 23 52 pm](https://cloud.githubusercontent.com/assets/352082/2812728/71f77656-ce6b-11e3-83f3-d84dd6429131.png)