Live: https://flamboyant-ardinghelli-549e43.netlify.app/
I made it without any reference and it works well.
Bugs fixed: Double clicks not possible, 4th tile can no longer be openened.
Dark mode implemented; the choice of the color mode is remembered by the browser.
btw I am terrible at this game. I made it with 3 equal tiles instead of 2 to make it easier to train memory. With less distinct shapes/numbers to track I can easier concentrate on remembering the position of the number rather than the number/shape itself.