Mortage page using displex flex

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

The JS code

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

I had to use JS to solve some CSS features, like hover effects that should activate more than one element.

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

How do I change the color of the radio input when it's selected? Mine is still blue. Also, what is the right way to calculate the mortgage? I just made the calculator function, but the results are only symbolic.