First, thanks for helping us out with this, it’s a nice effect which may help others, too.
You’ll want to set it up so the site header is hidden
Done. However, with Layout > Navigation Position: Float Left (as mentioned by you at the beginning of this thread), the Menu dissapears. So I changed that to Above Header, aligned Right, and thus the menu is visible.
Then add a menu logo to the regular menu (Customize > Menu Plus > Sticky Menu)
Did: the logo item to be active in regular, but not Sticky, by setting Menu Logo Position: Sticky. Is that correct? Because for normal position there is no logo visible (obviously).
Set the sticky menu effect to none.
Then set a taller than usual menu item in “Customize > Element Spacing”.
I set Element Spacing > Primary Menu Elements > Height: 150
So, that’s the status online at http://www.susala.ro/gp-test. Waiting for your input, and thanks again.