chore: add a couple of accessibility improvements

Hey guys, based on a11y's [checklist](http://a11yproject.com/checklist.html) I'm suggesting a few accessibility improvements:

- [x] Ensure links have ```:focus``` state.
- [x] ```<form role="form">```
- [x] Associated label for all form controls (e.g. input, select etc.)

I also tested all background colors against the actual text colors and it's all fine!