Congrats on publishing! I got the bonus workflow #1 in your slides to work but am having an issue with #2, I think it should just be CSSTargets[doc, "body"][[1]] (not [[1,1]]), if I change these lines in your presentation's last slide:

body = styleDataCell["Notebook", Notebook,  CSSTargets[doc, "body"][[1]]]
h3 = styleDataCell["question", Cell, CSSTargets[doc, "h3"][[1]]]
h1 = styleDataCell["h1", Cell, CSSTargets[doc, "h1"][[1]]]
li = styleDataCell["li", Cell, CSSTargets[doc, "li"][[1]]]
p = styleDataCell["p", Cell, CSSTargets[doc, "p"][[1]]]
h2 = styleDataCell["h2", Cell, CSSTargets[doc, "h2"][[1]]]

I get the output on the left (which doesn't look exactly right):

Ah, I posted before seeing your beautiful tutorial (somehow the paclet documentation didn't index until I restarted the front-end). All the examples in 'paclet:CSSTools/tutorial/CSSTools' work just fine!

Here's the output of your tutorial example (I'm using chrome), it only misses minor things: the FontFamily looks wrong for "h2", the small-caps of the text in "question" cells are missing, and the color of hyperlinks are a bit off...

Two follow-up questions:

1. Are there any methods in CSSTools to better capture these missing pieces of typographic information?
2. When it fails on some important property e.g. border-radius, how could I add support for that property? Thanks!

CSSTools has been released!

• Community Post Announcement
• Wolfram GitHub Page
• Direct v1.2.1 paclet download

The CSSTools package is soooo close to a solid first release. It makes this post almost obsolete since I've reworked the selector parsing to match the tokens from my CSS tokenizer, but that all should be hidden from the end-user. Slight name changes, though. In any case, I'm continuing to update the documentation for the CSSTools package with feedback from my colleagues. (Documentation never really feels complete, right?) Priorities are still the 12.1 release, but I'm going to push for it getting onto Wolfram's Github page after the release.

I like the package. Clean implementation too.

On a related note here are two other CSS selector methods, one using a real XML processing library in Java rather than any WL hacks: https://mathematica.stackexchange.com/a/183970/38205

This will be as robust as JLink is (i.e. very robust). It is object-oriented and so much, much nicer to work with than the standard Mathematica XML headaches.

And another one I wrote up that uses pure Graph methods to implement selectors in terms of a DFS: https://mathematica.stackexchange.com/a/184417/38205

This one still performs quite well, though, and for very complex queries is conceivably cleaner than a pure Cases/Positions method. Also it references a proper Graph and thus can also be object oriented and thus attribute and property lookup from nodes is nearly instantaneous.