Layers Automatic Repositioning

I have 3 layers on my page, 1 going across the page for the full screen width, while the other 2 share the rest of the screen as right-left, from under the top layer to the bottom of the screen.
When you resize the window, the text re-wraps itself in all layers, which also grow towards the bottom to accommodate all the text.
The problem is in the top layer that overlaps the other 2 when growing, mixing the text.
I am looking for a way to push the 2 bottom layers further down the page while the top layer height grows, which would be like dynamically redefining their top positioning.
Many thanks, Nico