Align content elements within parent container

I have a container (for argument's sake, let's say it's a div) which has a different number of elements inside it.
The parent container can be resized, and I want for the content elements to resize as well, but… I have some requirements.
Four elements: 1,2,3,4
1,3 and 4 are the same size, 2 is twice the size of 1
I want to be able to have them resize based on the width of the parent container, but keep their aspect ratios (more or less, at least).
There will never be MORE than 4 elements on…
Align content elements within parent container

See original post by PoPSiCLe