Set binding edge for inner and outer margins? (Landscape, long edge binding)

[sasha.strong]

Hello,

I am preparing a document in landscape format which I wish to top-bind (i.e. long edge binding). I would like to create a top margin that staggers depending on even or odd page number (so that the top edge still has a nice margin after binding) using the Inner margin option in the Margins palette.

However, despite the document being in landscape and having attempted to print and select long edge binding, Inner and Outer only control the left and right margins of the document.

Is what I wish to do possible? Any guidance would be greatly appreciated.

Thank you!