optimize accessibility

### General

https://developers.google.com/web/fundamentals/accessibility/

### Forms

https://www.nngroup.com/articles/errors-forms-design-guidelines/

### Tabs

- [x] Add `tablist` role to the `

` to indicate it contains tabs.
- [x] Add `presentation` role to each `
• ` to bypass its list item state.
  - [x] Add `tab` role to each `` to incidate it is an actual tab.
  - [ ] Add `href` and `aria-controls` to each `` to reference its tab panel.
  - [ ] Add `id` to each `` as a reference for its tab panel.
  - [ ] Add `aria-selected="true"` to the active `` tab.
  - [ ] Add `tabpanel` role to each `` to indicate it is a tab panel.
  - [ ] Add `id` to each `` as a reference for its tab.
  - [ ] Add `aria-labelledby` to each `` to reference its label.
  - [ ] Add `hidden` to each inactive `` to indicate it is hidden.

  https://gist.github.com/jonathantneal/435478e415bfe4f54d06