[the_other]

I detect a pungent "code smell", and probably a design bug via your example selector.

Does the designer really want such a specific edge case to an edge case? Can they explain or justify it according to the design patterns they laid down? Why are we using such a general ".container" to specify a ".button", and whilst we're at it why do we have a "button" AND a ".button". Our codebase was going off the rails long before we reached this (admittedly scary-looking) selector. There was a better way to do what we're doing, several iterations ago, and people who cared about the ux+information design and the CSS should have caught it sooner. Go back to them and fix the problem there rather than let this horrible selector pass code review.

We wouldn't stand for this in the TS/JS codebase. Why do we put up with it in the CSS?

To be honest, I was never on board with the "classes everywhere" approach. IDs are fine when they identify a single item on the page. We lost something when we stopped using the language as it was designed.

[ironmagma]

I think the issue is that CSS is somewhere between unopinionated and encouraging complexity. Is that the best kind of selector? Certainly not, but in Bootstrap, one of the most widely-used CSS packages, it was trivial to find a similar one: `.table-striped-columns > :not(caption) > tr > :nth-child(even) `, so it definitely happens a lot.

Also a lot of it comes down to the original plan to have semantic HTML, which ultimately failed. But we rarely talk about whether semantic CSS is possible, I think the assumption is that it is. But IMO it's not practical because of the poor specificity controls. That's something I'd do different, add in a manual specificity level (like how z-index has manual weights).

[the_other]

I don't see so many problems with that Bootstrap selector. It's long, but right from the first class to the final element selector it's fairly obvious why that clause exists. In fact, the left-most one explains all the rest: from reading it, I can tell what it does and _why_ it's that long. Your earlier example, much less so.

> the original plan to have semantic HTML, which ultimately failed

I feel that browser developers still build browsers with this in mind. You can see this expressed in the default ARIA roles, for example. I feel that developers of large web apps are the ones who aren't thinking about the semantics the right way and who think semantic HTML has failed. It didn't, they gave up trying to use it. Most of us think only in terms of using JS to render anonymous boxes, rather than about outputting an implementation of an underlying information design. Browsers and HTML still supports that very well. We're wrapping all the conceptual design up into JS and components, and treating the HTML + CSS as some kind of dumb output... when in fact that's the browser's job, and it hides that dumb render from us on purpose. If you use your web framework to output an expressive information design, the browser will render it just fine and more of your code will make sense (IMO).

I don't think you gain much from allowing manual specificity. No-one finds managing z-indexes easy. In fact, I think manual specificity would accentuate the problems we already have. You can fix most z-index issues by not using it, because the stacking is mostly handled already for you by the browser. Imagine trying to find the "specificity 203" in your codebase, or to establish a pattern for which disparate Thing A on the page is the same specificity as a Thing B. It'd be harder than the current system, I"m sure.