Responsive landing page using CSS, JavaScript MVC pattern

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

I used the MVC pattern for this project, saved all the data, and used it in the Thank You section. I would create this project with just one button next time.

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

I couldn't implement this project with only one button, so I created one button container for every section also this project has a lot of CSS but the JavaScript part was not hard.

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

I would appreciate it if you could help me create this project with just one button, also I am looking forward to seeing your comments about the code and project.