does anyone know of a CSS ONLY method to flip the vertical order of two elements, each of unknown height, other than changing the order in the source code, of course.
As in: You want the one lower in the source to appear visually before the other one or vice versa.
If so that would not be possible with dynamic heights.
As you probably know we can use relative positioning to swap elements horizontally but they have defined widths when that is done.