A while ago when the flexbox layout engine was a hope and a dream for the future i created a Pen. It was mainly to try and get a feel for what might one day be the way we build websites.
I made it mainly for my own sake but i think it turned out to be a decent learning tool for people wanting to get a hang of how all this works. Flexbox is a bit tricky to wrap you head around, epecially if you, like most us us, you’re used to laying out pages using floats.
Flexbox a insanely powerfull and getting in on the groundfloor and starting to use it on pits and pieces in your day to day work is a good way get used to working with the syntax. For example i recently used flexbox in a single element to get quick and dirty vertical centering on buttons that had varying lines of text. (i used this technique)
Now the flexbox layout engine is close to being a viable option for production and i thought i might need to take a look at this thing again.
Taking more than a few hints from how Bootstrap does their layout classes, so for users of bootstrap it should be pretty easy to get into.