m 		= 60px nav height

				.b-0 		= remove bottom border (only with transparent use)
				.transparent	= transparent header
				.translucent	= translucent header
				.sticky			= sticky header
				.static			= static header
				.dark			= dark header
				.bottom			= header on bottom
				
				shadow-before-1 = shadow 1 header top
				shadow-after-1 	= shadow 1 header bottom
				shadow-before-2 = shadow 2 header top
				shadow-after-2 	= shadow 2 header bottom
				shadow-before-3 = shadow 3 header top
				shadow-