Use CSS for colors of VWordPress and VHomeLink

[obulat]

Fixes

Fixes #4998 by @obulat

Description

This PR adds CSS variables for the contrasting text color and for the focus ring color so that the logo elements (VWordPressLink and VHomeLink) do not use JS to determine colors, even when the colors don't match the current color mode (i.e., on the pages modal, which has black background both in the dark and in the light themes).

To prevent some of the focus styles overriding each other, I changed focus-slim-tx class to only apply on focus-visible. Otherwise, it changes the ring color not only for the element in question, but for child elements, and sometimes is difficult to override.

Testing Instructions

Run the app using ov just frontend/run dev
Open http://localhost:8443 in a narrow window, and click on the menu button in the top right corner. Use the keyboard to navigate though the contents. The focus rings should be yellow, in dark and in light themes. The WordPress and Openverse links should have correct colors.

Checklist

• My pull request has a descriptive title (not a vague title likeUpdate index.md).
• My pull request targets the default branch of the repository (main) or a parent feature branch.
• My commit messages follow best practices.
• My code follows the established code style of the repository.
• I added or updated tests for the changes I made (if applicable).
• I added or updated documentation (if applicable).
• I tried running the project locally and verified that there are no visible errors.
• I ran the DAG documentation generator (ov just catalog/generate-docs for catalog
  PRs) or the media properties generator (ov just catalog/generate-docs media-props
  for the catalog or ov just api/generate-docs for the API) where applicable.

Developer Certificate of Origin

Developer Certificate of Origin

Developer Certificate of Origin
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Developer's Certificate of Origin 1.1

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(a) The contribution was created in whole or in part by me and I
    have the right to submit it under the open source license
    indicated in the file; or

(b) The contribution is based upon previous work that, to the best
    of my knowledge, is covered under an appropriate open source
    license and I have the right under that license to submit that
    work with modifications, whether created in whole or in part
    by me, under the same open source license (unless I am
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    it.

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    are public and that a record of the contribution (including all
    personal information I submit with it, including my sign-off) is
    maintained indefinitely and may be redistributed consistent with
    this project or the open source license(s) involved.

[github-actions]

Latest k6 run output¹

     ✓ status was 200

     checks.........................: 100.00% ✓ 6400      ✗ 0   
     data_received..................: 1.5 GB  9.0 MB/s
     data_sent......................: 837 kB  5.1 kB/s
     http_req_blocked...............: avg=30.6µs   min=1.96µs  med=3.63µs   max=11.31ms p(90)=5.13µs   p(95)=5.51µs  
     http_req_connecting............: avg=26.24µs  min=0s      med=0s       max=11.25ms p(90)=0s       p(95)=0s      
     http_req_duration..............: avg=573.44ms min=56.81ms med=501.62ms max=2.34s   p(90)=1.03s    p(95)=1.13s   
       { expected_response:true }...: avg=573.44ms min=56.81ms med=501.62ms max=2.34s   p(90)=1.03s    p(95)=1.13s   
   ✓ http_req_failed................: 0.00%   ✓ 0         ✗ 6400
     http_req_receiving.............: avg=134.59µs min=41.73µs med=112.76µs max=19.19ms p(90)=176.81µs p(95)=203.43µs
     http_req_sending...............: avg=22.43µs  min=6.7µs   med=18.86µs  max=8.3ms   p(90)=24.83µs  p(95)=26.79µs 
     http_req_tls_handshaking.......: avg=0s       min=0s      med=0s       max=0s      p(90)=0s       p(95)=0s      
     http_req_waiting...............: avg=573.29ms min=56.68ms med=501.37ms max=2.34s   p(90)=1.03s    p(95)=1.13s   
     http_reqs......................: 6400    38.608419/s
     iteration_duration.............: avg=3.06s    min=1.13s   med=2.52s    max=8.63s   p(90)=5.97s    p(95)=6.26s   
     iterations.....................: 1200    7.239079/s
     vus............................: 9       min=9       max=30
     vus_max........................: 30      min=30      max=30

Footnotes

1. This comment will automatically update with new output each time k6 runs for this PR ↩

[github-actions]

Full-stack documentation: https://docs.openverse.org/_preview/5110

Please note that GitHub pages takes a little time to deploy newly pushed code, if the links above don't work or you see old versions, wait 5 minutes and try again.

You can check the GitHub pages deployment action list to see the current status of the deployments.

[AetherUnbound]

When I run this locally, it looks like the WordPress, Openverse, and Exit buttons on the menu are all either pink on light mode, or yellow on dark mode. Is that what's expected? Between my local copy and staging, the only difference I can tell is that the WordPress logo goes from yellow on light mode to pink on light mode.

[openverse-bot]

Based on the low urgency of this PR, the following reviewers are being gently reminded to review this PR:

@krysal
@dhruvkb
This reminder is being automatically generated due to the urgency configuration.

Excluding weekend¹ days, this PR was ready for review 7 day(s) ago. PRs labelled with low urgency are expected to be reviewed within 5 weekday(s)².

@obulat, if this PR is not ready for a review, please draft it to prevent reviewers from getting further unnecessary pings.

Footnotes

1. Specifically, Saturday and Sunday. ↩

2. For the purpose of these reminders we treat Monday - Friday as weekdays. Please note that the operation that generates these reminders runs at midnight UTC on Monday - Friday. This means that depending on your timezone, you may be pinged outside of the expected range. ↩

[AetherUnbound]

Drafting until questions can be addressed.