CSS: auto height on containing div, 100% height on background div inside containing div

Question

The problem, is that I have a content div which stretches its container height-wise (container and content div have auto height).

I want the background container,

Answer 1

Okay so someone is probably going to slap me for this answer, but I use jQuery to solve all my irritating problems and it turns out that I just used something today to fix a similar issue. Assuming you use jquery:

$("#content").sibling("#backgroundContainer").css("height",$("#content").outerHeight());

this is untested but I think you can see the concept here. Basically after it is loaded, you can get the height (outerHeight includes padding + borders, innerHeight for the content only). Hope that helps.

Here is how you bind it to the window resize event:

$(window).resize(function() {
  $("#content").sibling("#backgroundContainer").css("height",$("#content").outerHeight());
});