Creating a fullpage vertical Navigation on the left (/w flyout)

I’m actually at the start of a new project and want to have a pretty special navigation. It should be a little like (small vertical layout, full height and sticky with 90° rotated items) but with a additional feature:
When clicking on (or hovering) a main menu item the submenu should slide out behind the main layer from the left with the submenu items within. Full height, too.

I’m using BB Theme and the the Themer, too . But I’m not sure how to start best.
Using the usual TopBar Menu and trying to kick it to the left with some CSS? Using the Menu Module and customizing it?

What are your thoughts?

Kind regards


The BB theme has a vertical header layout, but isn’t anything like the one on the site you linked. To replicate that would require extensive custom code which is beyond our support scope.

Therefore, the best solution would be to use either a theme which has a similar header layout or use a third-party menu plugin something like ShiftNav, but again it would likely require custom code to match that sites vertical nav.