I don't like the key on this map. The actual map has some kind of alpha overlay that seems to go to fully transparent for the darkest parts, while the key is 10

I don't like the key on this map. The actual map has some kind of alpha overlay that seems to go to fully transparent for the darkest parts, while the key is 100% opaque black for the darkest parts. In parts of the map it's hard to tell if you're in the darkest area. A hover info window would be helpful.