If you're in the position of needing to interview someone about their skill and knowledge about CSS, it can be a little hard to think of things to ask on-the-fly. I thought I'd think up and round up some ideas for reference.
Exercises To Do
Seeing people's actual work is just as important as what they say. Seeing people work their through exercises live might be even more important. These are some exercises that aren't particularly difficult and anybody with CSS experience should be able to do. Watching/listening to them do it could be invaluable. Collab Mode on CodePen is kinda perfect for that (just saying).
... read the whole story at css-tricks.com.