This has been started on in so make sure that the code from that issue is reviewed as well.
A couple of notes to take into account when continuing:
Try to be surgical – have a high threshold for refactoring. We want to break as little as possible, especially when it comes CSS as people(and content types) may already have overridden styles.
We should stick to the one event system/interface that H5P is offering – this is to avoid any confusion, duplication of code, bugs etc.
1. WCAG 2.0 AA
2. Good Wai ARIA coverage
3. Important to test keyboard navigation and focus effects in all supported desktop browsers