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.
I wonder how this will work with i18n. Some languages might need to put the course name before the end of the sentence. It might be worth consulting with @sarina.