[interfacesketch]

Take a look at Pocket Grid. It's not a framework, but a tiny responsive CSS grid system. Given that many websites are relatively simple in layout and presentation, it may be all you need. It's a shame this grid system hasn't gained more traction (it's from 2013)

http://arnaudleray.github.io/pocketgrid/

And now for a bit of a rant...

For many websites, you don't need a framework. My (completely anecdotal) impression is that few web developers trim the fat from the frameworks they use. That is to say: the websites they create have many unused CSS rules and unnecessary scripts. This amounts to substantial extra KB being downloaded by website visitors even when it's not needed.

Additionally, many sites are over-engineered with excessive Javascript to render simple web pages (even when the site is not a web app).

[tmaly]

I did look pocketgrid last year. I could not get it to behave like something like bootstrap. It would be nice if there was a simple grid that just sort of worked on all the modern mobile and desktop browsers. I am ok with not supporting IE or other browsers that have a tiny market share