These are super basic issues that were flagged by the axe browser
extension.

I tried to change as few things as possible to avoid breaking anything
that might be making assumptions about the markup on this page.

Generally, there is a lot more work that would need to be done on these
pages to make them as friendly as possible to assistive technologies.

Relevant:
- https://dequeuniversity.com/rules/axe/4.1/landmark-one-main
- https://dequeuniversity.com/rules/axe/4.1/color-contrast