Beautiful site. Exactly how do you want the top of the page (the horizontal menu) to appear? Do you want less space above the header? Or do you want the menu to take up less space beneath the header? There are several items affecting the top of the page and some are absolutely positioned.
Also, the footer is fixed at the bottom of the browser window and will overlay the slider if the window height is shortened. Is that intentional?
Did not look at the dropdown menu, yet.