experimenting with hard-coded layers paralax speed instead of computed values
added new function for auto-resizing level-wide elements

level wide elements can be assigned using the special "level-wide" css class
experimental code to animate level building on first loading

temporarily using a drop cascade effect that will be improved later
fixed left floating not happening in all layers
properly set distinct backgrounds for world and sky layer
fixed predefined heights classes and tweaked a few sizing rules
added paris level elements rules
removed walls from paris level because it's outside instead of indoors
idles elements now invisible
(clean) disabled debugging rules