In the first two cases there should be as much whitespace between the bottom of the inner DIV (with the green border) and the bottom of the containing scroll-box DIV (blue border), as there is between any of the other sides of the inner (green border) DIV and the equivalent sides of the containing (blue border) DIV.

Scroll down. There should be as much whitespace between the bottom of this DIV and the bottom of the containing scroll-box DIV, as there is between any of the other sides of this DIV and the equivalent sides of the containing DIV.
Scroll down. There should be as much whitespace between the bottom of this DIV and the bottom of the containing scroll-box DIV, as there is between any of the other sides of this DIV and the equivalent sides of the containing DIV.