What is the best CSS framework for responsive layout?

Question

css

A year ago I used Bootstrap, but over time it turned out to be not enough for me and I decided to switch to something more suitable. Now I'm typing on Materializecss (by the way, how do you feel about it?) - it seemed convenient and easy to me, but on the other hand, it lacks a lot from the bootstrap, although I really like the grid. Now I want to look again for something else, but I don’t plan to leave matzcss, I just want to learn some other css framework and compare, and possibly work on both. We need good support for adaptive layout, so that the nishtyak is on all devices.
Which css frameworks are better than their competitors in your opinion. Why? Please describe not in a nutshell, but in more detail. Thanks a lot.

Answer 1

v4-alpha.getbootstrap.com - bootstrap now switched to BEM, uses SASS, flexbox layouts...

Answer 2

I use www.getmdl.io because it is supported by Google. Impressions - quite convenient, if you figure it out, but too "raw": not everything has been thought out and worked out yet ... While I'm following the development and gradually studying ...
Here is my current masterpiece