Moved styles from js to css

There were a few lines in west.js that made references to jQuery's
animate() method, with corresponding pixel values. By moving the
styles to the CSS and only using javascript to change classes, it will
be easier for the user to make changes.
Removed scrolling bug

On iPhone 4s, when the nav is visible, swiping left scrolls
first the background, and then flickers for a second to close
the nav.
Merge pull request #1 from jshawl/master

Decoupling javascript and CSS