a handful of minor style updates/fixes

including

search input is the correct width
![screenshot 2014-10-18 23 10 15](https://cloud.githubusercontent.com/assets/1681963/4691920/7ea7ae60-573d-11e4-97ba-4267192c009d.png)

share box follows styles of other popups, and social media icons are more consistent
![screenshot 2014-10-18 23 10 25](https://cloud.githubusercontent.com/assets/1681963/4691921/80b4e93e-573d-11e4-99e2-17e3642e9ffc.png)

:dog2: :dash: