Most popular container styling tweaks

- moar bold!
- less padding

### screenshot
![google chrome](https://cloud.githubusercontent.com/assets/80089/4677492/2b633252-55e8-11e4-9690-f860ef9aacd2.png)

have we got a standard for this, e.g. https://github.com/guardian/frontend/pull/6566/files#diff-e43720509864cf46f0b4cbfd7a64b544R28