All of them failed my ten second evaluation. It's amazing how many mediocre CSS frameworks that are out there.
From a quick look at the second horizontal strip that starts "what is this?", and without wasting time doing too much digging, it appears to be ultimately caused by using a grid layout for a heading followed by a few paragraphs, all of which fill the available (constrained) width, which amounts to one of the absolute simplest layouts possible in CSS - block. Last time I saw something similar, albeit with flexbox not grid, it was from a junior developer who appeared to have only learned flexbox and nothing else.
As a quick semi-fix, just disabling grid-template-columns on .base-layout is enough to fix almost everything except the constrained width.
The layout approach is based on this Kevin Powell video: https://m.youtube.com/watch?v=c13gpBrnGEw
It uses CSS Grid to create a centered, width-constrained content area while allowing individual elements to break out of it or span the full viewport width. This provides a flexible, consistent layout without the need for additional wrapper elements in the HTML.
CSS nesting has had full browser support for more than 3 years now, I recommend updating. I'll also add fallback for older browsers, but the Grid layout itself isn't the issue.
Yes, that's right. I thought I'd try it in that older browser that I still happen to have installed, as the user above didn't immediately let us know what that mobile browser was. It may or may not help by at least giving you a browser version you can use to test. As I mentioned somewhere else, it makes sense to use some sort of older browser as a proxy for older browsers in general, when testing.
Developers are always looking for new ways to do what we've always done, often using more technically complicated ways to recreate the simplest things. It's fun from the puzzle-solving point of view, but your choice of earliest browsers you want to support depends on your user base.
How's your ten second evaluation of it?
It's one of the reasons I'm planning on moving stuff over to Pico.
Or now, I guess, just writing some CSS from scratch, which I hate.