member areas Targeting Membeship Area elements

Hello, I need to target the main logo within the membership area only (a membership specific class I would imagine), in order to change the link out within the member area only with JS (it currently links out of this area and users get confused).  However I cannot find a specific class on the body or anywhere that specifies that someone is currently logged in.  Does anyone know of anyway to achieve this?  What might be different when a user is logged in that I can target?   Thanks