Some Great Flexbox Links Lately... | CSS-Tricks

Flexbox Froggy: A game from Thomas Park where by you learn about differnet flexbox properties and values by positioning a frog.
Flexbox Grid Finesse: Heydon Pickering shows off that useful feature of flexbox where a grid with leftover boxes can be distributed along the final line. But you can caress things a bit ensuring you don’t get a 4-4-4-1 situation and instead get a 4-4-3-2 situation with some min-width and :nth-child stuff.
Flexbox’s Best-Kept Secret: Sam Provenza shows off a method of pushing flex items away from each other without having to grow the element itself (or affect other items) with auto margin.