Ignore flex container children but not grandchildren

Question

I have a simple flex element with some children, something like this:

Answer 1

If the element is a child of a flex container, then it becomes a flex item. That's the general rule.

However, most browsers will ignore that rule when the child is absolutely positioned.

I'm not sure that's a useful solution in this case, but that's what you would have to do: absolutely position .subcontainer and make it flex container, so that the children become flex items.