CSS box-shadow hidden (z-index does not fix)

Question

I have a box-shadow on my #primaryNav div. Unfortunately, the shadow is being covered/hidden by the background of the following #page element.

Answer 1

As jlego already said a relative position should fix it. By the way I would suggest ensuring that there is no shadow left or right of the #primaryNav. Since #primaryNav has a width of 100% a shadow on the side makes a horizontal scrollbar appear.

For fixing this you could set a overflow:hidden to #iframe