In my opinion this is still the best option for CSS, especially in combination with React.
Most importantly it contains a ratio-based scale: http://tachyons.io/docs/layout/spacing/
Most importantly it contains a ratio-based scale: http://tachyons.io/docs/layout/spacing/
I've built some complex UI's with the same class name styles (Basscss). 99% of the time I'm reusing classes and I don't have to write anything custom.
Prototyping is great once you memorize the classnames.. Just write HTML, no need to switch to CSS files.
If you're working with global styles this is by far the most scalable CSS methodology as of right now IMO.
I don't know which editor you are using, but for TextMate I've written a 20 line-plugin that greps the tachyons.css file and gives me code-completion.
This article(written by the creator of Tachyons) helps to explain the issue: http://mrmrs.io/writing/2016/03/24/scalable-css/
Where I work, we're using it on a new project and while it definitely requires a lot of learning(and just generally understanding CSS), it's faster to debug with, easier to take care of edge cases, and the total size for our app is incredibly small.
Being able to design UIs without opening a single CSS file has made HTML pretty fun and I've found I'm much better at componentizing the right things.
It's a grid system, not framework, so it adapts to what you need.