Single column comming soon page (Sass, JS, mobile first)

Hey everyone :) Here is another solution from the newbie challenges. This time I paid more attention to CSS reset and used min(), max() and clamp() functions for setting font-sizes and some widths and paddings. Decided to add success confirmation on submitting correct form and found out this a little difficult for had to modify some of the written code. So the overall feeling after this challenge is that I need to write more scalable code... I would be greatful for any suggestions about that.