tip calculator app

What are you most proud of, and what would you do differently next time?

I tried to abide by the DRY principle and was able to simplify the validation and error handling, I think.

What challenges did you encounter, and how did you overcome them?

I found implementing the tip choice GUI was challenging. I used radio buttons to implement the choices so that only one can be selected. I had to hide the radio button, however, by setting its display style to none. I can still select it by clicking its label, but I was not able to select it by keyboard. So I am not sure if my solution was acceptable.

What specific areas of your project would you like help with?

I would like to hear suggestions on how to implement the tip choice GUI. Can I use radio buttons and make them visually hidden, and still be responding to the keyboard?