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

After much testing, I have verified that the original question is already right; missing just a couple of settings:

• the container_row MUST have position: relative;
• the children (...), MUST have position: absolute; left:0;
• to make sure the children (...) align exactly over each other, the container_row should have additional styling:
  • height:x; line-height:x; vertical-align:middle;
  • text-align:center; could, also, help.