improve accessibility

[nobodxbodon]

Related issues:

make gittip accessible to vision impaired people
Web should be mouseless - shortcuts for paging

I don't see feasibility without using existing front-end framework with good support in accessiblity.

[EdOverflow]

I believe the first step is to increase the contrast of the individual elements. That requirement is on this list: #4262

[nobodxbodon]

@EdOverflow the color contrast sounds like usability issue, while this is meant to focus on accessibility.

[chadwhitacre]

Contrast is definitely part of accessibility, though I'm not sure how it's part of performance (gratipay/gratipay.com#4262).