I encountered the problem that z-index is not as simple as it sounds.
After reading basically everything I found about it, I still could not figure out a solution. So here is my problem:
I just added
z-index:3 to each of the elements and it seems to produce the desired effect.
EDIT: New JSFiddle as the question has been edited: jsfiddle.net/jgbfhv1x/4