13th Challenge - Intro component with sign-up form

(I translated the sentences into English using 'translate.google.com'. Please understand if there are any strange grammar.)

Hello!

This is the 13th challenge! This time, I made a page with sign-in form!

I was able to have time to understand the form tag while making the previous two coming soon pages! Also, it's time to learn the box-sizing property!

As the number of inputs in the form increased to 4, I was worried about how to handle errors and submit.. I am very happy to find a way to solve such problems through this work!

I still think that there are duplicates in Javascript or css, so the next time I try, I will try to find a way to reduce the amount of scripts. I will study more!

Thank you for watching! > ▽<)/ If you have any other advice, please feel free to tell me!