CSS: How to position two elements on top of each other, without specifying a height?

Question

I have two DIVs that I need to position exactly on top of each other. However, when I do that, the formatting gets all screwed up because the containing DIV acts like there

Answer 1

Great answer, "mu is too short". I was seeking the exact same thing, and after reading your post I found a solution that fitted my problem.

I was having two elements of the exact same size and wanted to stack them. As each have same size, what I could do was to make

position: absolute;
top: 0px;
left: 0px;

on only the last element. This way the first element is inserted correctly, "pushing" the parents height, and the second element is placed on top.

Hopes this helps other people trying to stacking 2+ elements with same (unknown) height.