Considering the central role CSS has in TW, I think it should be regarded as a tool(s) like the others, i.e the operators etc. But it is a whole Pandoras can of
worms goodies in itself so it woudl be an ambitious project.
However, we could expand the idea in the
Theme tweaks tiddler. The setup is such that the Stylesheet has instead instead e.g "font-size: 14px" a stransclusion "font-size:{{tiddlerWhereFontsizeIsStored}}". And in the Theme tweaks tiddler, we have small editor fields so to directly manipulate the content of that value tiddler.
It would be great to extend this and make it much more dynamic. Imagine a script that reads through the Stylesheet (I guess the strict nice format in Stylesheet should simplify here). Then it can take each, um, "item" (classes, selectors etc) and re-present it in a format similar to the Theme tweaks tiddler.
If each "item" is separated (copied?) into a tiddler, this could let us include appropriate search tags which would simplify the all-too-familiar and disproportionate search-fiddle-try-and-fail process many of us must deal with currently.
Separating them into tiddlers would also allow for a lot of other interesting slicing-and-dicing and, I think, make it a lot easier to crate new themes.
Actually, the current Stylesheets are, as far as I understand, very much
not formatted in accordance with tiddler
philosophy. I.e they are currently one big tiddler with a lot of stuff you re-user from its various sections.
This is a good topic for a hangout IMO.
<:-)