Responsive ping coming soon page

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

I am slowly doing my projects with a mobile-first approach, practicing good JS, and CSS skills. There is a lot to improve. I couldn't handle the part where you click the button, the position of the input part is changed a little bit, it is ok in the mobile version, but not in the desktop version. So I would love to read if you have any suggestions about that