Age calculator using the Date object on js

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

I'm proud I could create a good logic to this hard (even looking easy) project. I'm proud I learned how to manage dates on js and how to deal with inputs, this is going to be important to a next project

Next time, as I'm a begginer and was dealing with a new type of logic that I never used, I would plan more, think more, and code what is necessary. I've lost much time coding and coding and i got to a moment that i was not even understanting what i was writing

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

The biggest problem on this project was calculating the dates. It may look easy, just do a plus/minus equation, but it's not this way. As there are years with 365 and 366 days, and there as months with 28, 29, 30 and 31 days, it got a bit harder to make a consistent and eficient logic. But hopefully, with times of planing and thinking and testing, I got a logic that solves all the variables of errors and incorrect calculations

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

I would like do get help on the js good sintax pratices