I mean, this has a lot of out of date information which I guess is not surprising for someone who says I'm not an expert and don't do production CSS, but it is weird to get the suggestions that are pretty reasonable for 5+ years ago.
This comment could be improved by adding specific examples and explaining what people should be doing today instead.
You know, this speaks volumes. Layout is a complicated business, sure, but CSS just keeps having monumental shifts in how you're supposed to approach it year after year; it's as if it's done without any overarching theory/vision but merely groping in the dark, trying things and fixes, and seeing what sticks and doesn't suck too horribly (this latter part is optional; remember Yandex's BEM?)