I think this is a good example of what CSS can do and probably was not easy to make but I will likely stick with Mahjong that comes with most Linux distributions as they follow rules that people I may end up playing against would know and they have many layouts. I could see this being applied to other things however such as games that require building or repairing something. Or something similar to Minecraft?

Impressive work!

Minecraft in CSS has been done, actually! https://benjaminaster.com/css-minecraft/

Discussion: https://news.ycombinator.com/item?id=44100148

I wonder if versus Mahjong Solitaire could be like Battle Tetris. I've never heard of people playing it competitively.