Originally Posted by dgatwood
The <div> element should have an explicit size—height: 100%; width: 100%; in the CSS. This should result in a <div> that fills the screen.
Again, that 100% means 100% of the container's height, and the container (probably <body>) has no fixed height, but rather is as high as needed to fit its contents. As humans, we assume it means "100% of the screen
height", but that's not what the spec says, and that's not what all renderers interpret (though it might be what some do).
Set it to "height: 10cm", or similar, instead, and it should work as expected (but not as wanted).
This, of course, unless I'm mistaken due to ignorance or misunderstanding of the specs