Couple of minor UI tweaks to improve readability

### Tabs

Before:

![2014-03-09 14-13-00 2014-03-09 14-13-10](https://f.cloud.github.com/assets/1131196/2368665/7939e10a-a7b6-11e3-83ec-a84c853e6911.jpg)

After: 

![index html 2014-03-09 14-13-30 2014-03-09 14-13-36](https://f.cloud.github.com/assets/1131196/2368666/897494a2-a7b6-11e3-9147-c2afec164b79.jpg)

### Sidebar

Before:

![2014-03-09 14-14-37 2014-03-09 14-14-44](https://f.cloud.github.com/assets/1131196/2368671/b1716d72-a7b6-11e3-8411-86c8249ea941.jpg)

After:

![index html 2014-03-09 14-15-01 2014-03-09 14-15-06](https://f.cloud.github.com/assets/1131196/2368674/befe4b04-a7b6-11e3-956f-cd8875442b0d.jpg)