Name some online resources that you reference when having CSS issues?

Being good at googling problems you are having is a valuable job skill. There isn’t any shame in it. There is shame in spinning your wheels because “you should know this.” If you don’t have time to do the Googling exercise above, just asking about resources can be telling.
Google is a pretty good answer (since it’s true and we all know it). But being able to name some specific sites is a good indicator they have done it a bunch and are familiar with the places they land and know their favorites. Stuff like MDN (Mozilla Developer Network) is a good answer.