Responsive landing page using flexbox, a media query and regex

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

I am proud of when I used regex on some validations since it is a way to shorten the code depending on the use, I sadly discovered this when i had advanced a lot so next time I will investigate more and use more regex.

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

My main challenges were trying yo use regex, it is my first time i see that so I investigated a little and tried to make my own code with it, shortening the code. this was not that hard but anyways, making the content of the card correspond to what the user puts into the input was easy, but then I had to make it to fill the rest with zeros. I was thinking on an idea until i figured out, I only had to make a function that added zeros while the length is minus than 4.

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

regex. I want to learn more about it to use in the future.