CSS cleanup

[Katsute]

Pending GA of https://github.blog/changelog/2024-10-01-evolving-github-issues-public-preview/

• Rewrite all selectors, remove outdated/redundant ones
• Fix tests and set up test repo
• Drop projects classic (gone) not used
• Drop print support
• 4/30 - Drop tasklist support (see changelog)

[Katsute]

https://github.blog/changelog/2025-01-13-evolving-github-issues-public-preview/

[Katsute]

https://github.blog/changelog/2025-02-18-github-issues-projects-february-18th-update/#tasklist-blocks-will-be-retired-and-replaced-with-sub-issues

[krystian3w]

So page now is nice for print? #59, It's a bit of a lime, as it really is some big markup to always check the print preview (assuming it's not some bug in MV3 that the sheets are no longer injected).

[Katsute]

print view was an extra thing I had to keep checking every time something needed to be updated, tbh not worth maintaining that part since no one is printing github pages

[Katsute]

https://github.blog/changelog/2025-04-09-evolving-github-issues-and-projects/