https://en.wikipedia.org/wiki/Mastermind_(board_game) is a challenging code-breaking game. There are 6 colors and a 4-length code to decypher. Can you break the code? This Mastermind game was developed using CSS and HTML (no JavaScript), and it has 4 different codes to guess. --- Thanks to https://twitter.com/racascou for the design suggestions and https://codepen.io/fionnachan for a great confetti effect (that I shamelessly modified a little, sorry.)