Cards (Inclusive Components)
Some of the components I've explored here have specific standardized requirements in order to work as expected. Tab interfaces, for example, have a prescribed structure and a set of interaction behaviors as mandated by the WAI-ARIA specification. It's at your discretion how closely you follow these requirements. Research may show

As the histimines sweep over me, wrapping me in the sweet, sweet death of being suffocated by my own mucus, I just want people to know…
I still stopped to smell the flowers.

My initial take is that Micro$oft acquiring GitHub is it could (should) be a good thing. Feels like GitHub product teams have been throwing a lot of crap against the wall to see what sticks. Hopefully this will help focus efforts. Also turn Atom Editor & the desktop app over to the community and focus on improving Code, which is already superior to both.