i have two pages which come very close to what i want
1) This one (allows position;fixed but cuts opff top and left when window too small)
2) This one (positition;fixed prevents vertical centering)
the 1st behaves how i want except when the window gets too small to contain the pic of the tree(the position;fixed one) it gets cut off at the top and the left instead of stopping when it gets to the top and left.
the 2nd page stops at the top and the left but moves with the page when scrolled. when i apply the fixed position to it does not stayed centered.