You also have to set the position of the brand to relative and than give it a Z-Index greater than the navlinks.
Set the navlink to relative aswell and give them a lower Z-Index
From what you say, though, it seems that in order for one to do something more “out-of-the-ordinary” at Webflow, one needs to be really proficient in CSS3 and HTML5, and all the cross-browser quirks etc.?
From your explanation, it seems pretty advanced if you ask me.