Make side panels collapsible

[Kronzky]

Not sure if this is still in development, but it would be nice if we could collapse the side panels (for species & activity selection).
They take up quite a bit of room (nearly 50% of the screen) that could be used to display the map.
Once you've made your selection you don't really need those panels anyway, so it'd make sense to hide them until you want to change the selection.

Update: Here's a intermediate fix (if you have uBlock or something similar installed).
It'll keep the side panels small until you move your mouse over them, and then they expand.
Put the following lines into your custom filters, and you're all set:

mathartbang.com##:is(#control, #dropzone):style(width:150px!important)
mathartbang.com##:is(#control:hover, #dropzone:hover):style(width:300px!important)
mathartbang.com##.leaflet-right:style(width:100px!important)
mathartbang.com##.leaflet-right:hover:style(width:250px!important)