Style panel layout

Remove drop shadows from panels: Currently the list/settings panels have a drop shadow that makes it appear as if those panels extend over the map and hide content. However, this is not true. The list/map/settings are all at the same level and the size of each panel constrains/impacts the size of the other panels. Therefore we should have a style that is more like a border.

Update sizes on mobile: We currently switch from multiple enabled panels to single panel mode at 640px. That screen size is the exact size of two panels which means that if all three are open you cannot see the map panel (screenshot below). Please update the application styles to be more mobile friendly.