ECOM-811 design and layout changes

@wedaly @stephensanchez @rlucioni here are the style and text updates. Unfortunately I had to use teh dreaded !important in my Sass to override some ridiculously specific selectors, but after the A/B test we can clean this up by removing the legacy styles.
In my JS test branch, I changed this from a string to a bool.  It should be `if ( isActive )`