The author has an enthusiasm for a new piece of CSS that I haven't seen in a solid decade. I appreciate it a lot. In my 20s I would have tinkered with the possibilities of this thing for hours/days. Trying to get stuff to work in CSS brought me joy. Now it's kind of easy, thanks to flexbox, grid, and the fact that most websites and apps follow standard design principles. We've "solved" web UI, for the most part.