Overlapping cards in a white version of the game. I just changed the Settings to a white background, everything else was sorted out automatically.
I’ve solved my five card problem. I’m not sure if I’ve cheated or not, but I am sure that it works.
The way it works is by giving elements in the StackPanel a negative left margin, so that they go into the element to the left. The StackPanel only seems to use the width remaining width for each item in the panel, so I end up with all the card displays overlapping nicely.