This looks nice. I like the name. But poking through the code it seems to be more of a slimmed-down Bootstrap rather than a fresh/new approach to minimalist CSS. Which has it's uses no doubt.

I personally love http://basscss.com/ for a minimal and side-effect free (the real goal) CSS framework, as it has one of the best class naming schemes I've seen.

Each component is focused on doing one thing and one thing well. You basically build up the styles with each class you add to an element. Composed via a combinations of smaller pieces, unix style, rather than complex multi-layered components with deep nesting. Which is an interesting approach when you try to apply the same idea to your own CSS. See the Design Principles for more: http://basscss.com/v7/docs/reference/principles/

The code is also very readable and integrates perfectly with PostCSS. They also have a React version.