I get that they wouldn't want to advertise their competitors, but the comparison matrix on the page makes mini.css seem tiny, where as a google search shows it's the biggest popular framework like this.
Mini.css is 7KB gzipped, Milligram[0] (the first google result I see for "minimalist css framework", mini.css is second) is 2KB gzipped. Pure.css[1] (the third result) is 3.8KB gzipped.
[0] - https://milligram.github.io/ [1] - https://purecss.io/