If you are looking for a quick way to get up to speed with flexbox or css-grid you should check out
https://flexboxfroggy.com/
and
https://cssgridgarden.com/
They are fun little tutorial games that introduce the basics
Yes, and we'll be adding support for that as opt-in in v5.1.0! Here's a little teaser: https://deploy-preview-31813--twbs-bootstrap.netlify.app/doc....
And it seems to be well supported: https://caniuse.com/css-grid
Thank you.