Fixed position but relative to container

Question

I am trying to fix a div so it always sticks to the top of the screen, using:

position: fixed;
top: 0px;
right: 0px;

However,

Answer 1

When you use position:fixed CSS rule and try to apply top/left/right/bottom it position the element relative to window.

A workaround is to use margin properties instead of top/left/right/bottom