I have two separate `DIV`s one `position : fixed` for notification bar, and one for main container, when I give the `container` some `margin-top` , this also pushes my notification bar!

Here is a fiddle: <http://jsfiddle.net/Zh9k8/2/>

and, I know I can stick it to top of the page with `top : 0` but I want to know why does it happen.