Things seem a bit better on the Qt side of things, but it suffers resolution scaling issues. Most KDE/Qt themes I’ve tried can’t draw correctly at non-integer scales.
Personally I think that CSS is actually pretty badly suited for the use case of desktop UI toolkit theming. It’s fine for one-off apps but quickly becomes a mess when it needs to be part of a larger more flexible system.
Here are some possible alternatives: https://selfh.st/alternatives/notion/
Capacities has one-click export of all of your objects (notes/pages) with a sensible folder structure that produces markdown with frontmatter and includes all media attachments. That's good enough for me.
If you don't feel like watching the whole film (and you definitely should, the first third is all lead-up and it's masterfully done - and the aftermath part is the most believable post-apocalypse I've ever seen in a movie) you should at least watch the bombing scene: