Refactoring of js code


I am learning fcc and mandarin at the same time. So, I made this simple flashcards app. I would welcome any suggestion / criticism of the js code. Thanks.
P.S The audio format is not supported in firefox


when it comes to words like mianbao a space between it is neceary. since it’s very confusing now. specialy when u want to use it to learn something. also the use of headletters is not constant.
also the speech for dou sounds of

Thanks for your feedback. Really appreciated :slight_smile: