- Changed `wc_addons_wrap` to `wc-addons-wrap` to adhere to stylelint class rule.
- Removed `max-width` from `wc-addons-wrap` – we need the purple header to stretch to full width. Added new `wc-subscriptions-wrap` class to give the `max-width` to the My Subscriptions page.
- Changed width of product cards to use `calc`, so that any trailing odd-numbered card has the same width as the others.
- Fixed some stylelint issues. Moved style blocks to address `no-descending-specificity` warnings. Remove quotes from URLs and font names that don't need them.
- Gave `#screen-meta-links` absolute position on the marketplace page, so it overlays the full-width purple header.