Video page redesign

- New video page style
- Moved some of the content css to their own directory
- Removed some old sprite files

![image](https://cloud.githubusercontent.com/assets/960919/3539916/7288ae84-083e-11e4-9a33-792fe491e9a7.png)

![image](https://cloud.githubusercontent.com/assets/960919/3539903/500d9f40-083e-11e4-9456-e4e60d64c7a3.png)

![image](https://media.giphy.com/media/qXVokpHxe0C9W/giphy.gif)
if you specify 50%, Sass is supposed to take care of this. Did it not?