I don't understand why a resizable containment to the container does not factor in padding and margins. See my jsfiddle
Is there anything I'm missing?
I think something is off for the maxHeight. If it's retrieving outerHeight(true) then I shouldn't also need to include css('margin-(top|bottom)'), but it looks funky without.
Also, for a more complete implementation, you'd have to look at all the container's children, in case there was more than just a header involved.
Edit:
I replaced the margin-top/bottom with the header's padding, since that would expand the resizable height.