Tip calculator app (HTML; CSS; JS)

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

I am proud of my procent buttons and a input. I learned more about 'this'.

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

Buttons and input were difficult(select those and use procent). I did it with 'this', and 'if' for checking what user selected.

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

I would like to have counsellings about how I can write my code better more optimistic.