Penguin Monster's Wordle

I made this Wordle clone in one night.

Controls:

Use the letter keys on the keyboard to type letters. Press enter to submit a six-letter guess of what the mystery word is. After submitting the guess, the letters will have backgrounds coloured according to the following rules:

• A letter with a green background will appear in that position for the mystery word.
• A letter with a yellow background does appear in the mystery word, but does not appear in that position.
• A letter with a black background does not appear in the mystery word.