CSS CODE to remove wordpress header

I will pay you 15.00 if you send me the code to make this header in gray only 30 px - right now it is 150px. See attached image. The first person to give me the code that works, I will assign you and pay the 15.00. I am trying to add code to an INDIVIDUAL WORDPRESS PAGE in the custom CSS area. See attached. I just need to know what I need to put in that area. When I change to 30 px when "inspecting the element" it changes - I just don't know the css code to make it work.