My main takeaway was the following: Z-index only works on positioned elements. If you try to set a z-index on an element with no position specified

My main takeaway was the following: Z-index only works on positioned elements. If you try to set a z-index on an element with no position specified, it will do nothing. I know I have scratched my head in the past trying to get z-index do what I want, and this knowledge probably would have helped!