lucy24 - 8:18 am on Dec 12, 2011 (gmt 0)

What happens if your user's window is something other than 700 pixels high?

I've had the best results setting a height value on the html rather than on the body.

html {min-height: 100%;}

does what it's intended to do (keep a footer at the bottom of the screen even if the text is short).

And then once you've got a single block with constrained height, anything inside that block-- including body inside html-- can be set proportionally.