Material Design, CSS only framework.
Check the documentation here.
I built this framework a few years back mainly for experimentation to see how far CSS could be pushed functionally. It's great that this repo is still active with issues and pull requests and a decent amount of stars, but to be honest, I did not build this to be the next bootstrap. It is far from perfect and there are likely better solutions out there for what you're seeking to do.
As of 26th Sept 2017, this repo is no longer being actively maintained. I will check every now and then to merge PRs for small fixes.