responsive product list and cart page

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

To properly update the cart with the user interactions was a challenge. I did it with pure javascript but it could be better using react or other libraries.

I had a problem with loading the data file using fetch(). I think I got the hang of it by the end, though.

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

I created all the cart items and menu buttons at the load time. As items are added to/deleted from the cart, those are unhidden/hidden in the cart. Initially, I felt that adding/deleting those cart items on the fly would be expensive, but maybe not so much. As a result, my script has gotten more bloated and complicated. I wonder what would be the best practice?