Confluence gadget height not working with Vertical + Horizontal nav groups

[iec989]

I basically have an Horizontal nav group within a Vertical nav group. Within each of the nav items, I've added a Confluence gadget. 

The height is however 100px or so. 

I've tried adding it within a DIV with 100vh height, but that doesn't do the trick. 

A workaround that worked, very dirty, is adding a lot of empty new lines within the nav item (right below the gadget). The gadget then manage to expand the total height that occupy those spaces.

What would be the best approach to solve this corner case?

[iec989]

I've added a CSS stylesheet at the bottom of the page and controlled the iframes from there - it works!