I've been a big fan of the puzzle video game Blue Prince and its box logic puzzle. I wanted to do these outside of the game so I made a website that generates daily solvable puzzles based on the format.
Each round, there are three boxes with some number of statements written on each. There is at least one box which only tells the truth, and at least one box which only lies. From there, you want to figure out which box has the gems inside and to open that box.
Let me know what you think!