Placing a fixed element above browser's scrollbar

Question

Basically, I want to show an overlay div that covers everything on the page, including the scroll-bars.

Is it possible for a fixed element to appear above the page\'

Answer 1

No, html elements cannot render over the browser chrome (scroll bars, etc).

For more information on how pages are rendered, read this article Web Browser Engine

Also with Z-index, the lower numbers are behind objects with higher numbers. More or less, for more detail see the CSS spec