Note: it must be a direct child of Views element and be BEFORE all views.
But then instead of a bottom toolbar, make it a left sidebar. I didn’t use panel, as I didn’t want it to be an overlay.
Use CSS for a smooth sliding transition, and CSS to hide it when viewport is narrow.
Most likely you don’t want to use the master/detail, it’s not really appropriate for this, I wasted some time trying to use master/detail before fully understanding it’s use case.
There’s probably better ways to do it, but am happy with the result. Hope that is at least a little bit helpful!