A quick concept I put together this morning. I'm sure this could do with some refining. Feel free to clone and improve.
Couple of things I picked up on, all of the panels are visible when editing in the designer. Is there a simple way of sorting this without over-complicating the structure? I guess you could set individual panels to hidden whilst working on them.
You need to make sure, if you add or remove nav links, that you update the interactions for them. So that when you hover over contact, it sets the about and services panels to display: none. Etc.