Modal Dialog Example: Increase z-index of dialog backdrop

[emamoah]

Relates to #2842.

Initially considered a bottom-padding adjustment, but that would create visual inconsistencies.
This solution seemed best, since, in my opinion, the user would not need to use the "Back to Top" link when the modal is open.

Preview link

Modal Dialog Example in compare branch

Review checklist

Reviewers: To learn what needs to be covered by each review, Follow the link for the type of review to which you are assigned.

• N/A: Editorial review by reviewer_id
• Functional review by jongund
• Visual design review by reviewer_id
• N/A: Accessibility review by reviewer_id
• Code review by reviewer_id (
• N/A: Test review by reviewer_id

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WAI Preview Link (Last built on Thu, 26 Oct 2023 07:26:25 GMT).

[jongund]

Looks good to me, fixes the problem.
Tested on my iPhone and the close buttons not obscured and the close button works.

[css-meeting-bot]

The ARIA Authoring Practices (APG) Task Force just discussed Issue 2842 - Bug in modal dialog example when accessed on mobile.

The full IRC log of that discussion

<jugglinmike> Topic: Issue 2842 - Bug in modal dialog example when accessed on mobile
<jugglinmike> Jem: jongund reviewed; we need one additional reviewer
<jugglinmike> Matt_King: This is a CSS change. I don't feel comfortable reviewing it myself
<jugglinmike> The patch is gh-2843
<jugglinmike> github: https://github.com//pull/2843
<jugglinmike> Andrea_Cardona: I can take a look at this. I should be able to do that by the end of the day
<jugglinmike> Matt_King: Sweet!
<jugglinmike> Jem: I'll assign you on the pull request

[andreancardona]

tested and looks good to me!

[mcking65]

@howard-e

Why were no checks run on this? At a minimum, shouldn't CSS Linting action have run? I don't see anything about it in the checks. The only thing there is the preview build.

[howard-e]

@mcking65 I tested this change in my own fork, howard-e#60 and confirmed that the CSS Linting step does run. I also see other recently pushed PRs where the CSS Linting action works as expected, so this should be fine.

My only guess is that because this is Emmanuel's first PR in this repo, and there would have been an Approve to run workflows. Maybe a GitHub bug may have prevented that from running properly depending on when that button was clicked (but this is a huge guess). You can try pushing a[n] [empty] commit to this branch if we'd like.