Accessibility issues

[lfarrell]

Fix for: #1395
Fix for #1393
Fix for #1430

Also addresses color contrast issues and duplicate ids in search results

Should fix all accessibility issues in arclight.

[seanaery]

I like where you're going with it, but as far as I understand it, a <dd> can't be a child of <dt>. The missing indentation makes it a bit confusing. I wonder if a small tweak like this would work:

<dt class="visually-hidden">Collection Context</dt>
<dd>...</dd>

[lfarrell]

@seanaery That seems to work. I've pushed up the change.

[seanaery]

This looks too big in the UI -- it makes the view more/less link bigger than the title header. I'm curious what the accessibility violation is with the existing style. Looks like it's --bs-link-color which translates to #0D6EFD which is 4.5:1 on white. If it's used on any non-white backgrounds I think it'd be better to darken it in those contexts (can even use BS5

shade-color() functions).

[seanaery]

I would leave this in -- I think it is useful to visually highlight the currently selected item. And now that you have unlinked the current highlighted item, its text color is black so there's no contrast issue to resolve on the highlighted document.

[seanaery]

This is looking great and I am excited to get all these fixes into core. These are big important wins -- thanks for working through all of this.

I completed a review and left a few inline comments. Just a couple more thoughts, taking an updated look at the branch:

1. I believe we should keep the background-color highlight on the currently-viewed item in the sidebar; I think it's especially helpful if you have a collection with a deep hierarchy and you're trying to navigate between different component nodes at different levels.
2. There's a lot here in one PR with 10+ commits, some of which undo or supplement the effects of others. When this gets merged it'd be a shame to squash this all into one big "Accessibility issues" commit, but leaving it un-squashed would also leave a bit of a confusing paper trail.

I wonder if you might either 1) break the changes from this PR out into 5-7 smaller separate PRs; or alternatively 2) make a copy of the branch, do an interactive rebase, e.g. $ git rebase -i HEAD~15 and edit down / reorder the commit history with fixup, pick, reword, etc. so each of the final fixes here has a clear paper trail, and then post that branch for one new PR.

[lfarrell]

This PR has been split out into multiple PRs, which replace this PR.

• Fix issue with breadcrumbs having invalid markup #1468
• Don't link to currently selected document in the tree #1469
• Wrap grouped results in dl tag as their contents have dt and dd tags #1470
• Fix issue with duplicate ids on the page #1471
• Show "View More/View Less" links as a darker color #1472
• Remove aria-hidden attribute #1473