leaflet: Make the shadows crisper
HdyLeaflet
now has cool transitions where the visible child casts shadows on the others. To make them look crisper, we could augment the contrast by adding a 1px transparent white border to the widget casting the shadow during the transition. It could be implemented as an overlay and shouldn't change the size of anything.
CC @cassidyjames, @exalm, @sam.hewitt, and @tobias.bernard as it may interest you.