Javascript animate and Nesting CSS experience!

Took me 5 days to Complete this challenge!

I decided to use some new features like Nesting CSS, <dialog> in HTML & .anime() in Javascript. And suprisingly, they are not completed. I got a few bugs in my code and took me a hard time to debug them. Therefore, I recommend using traditional stuffs before jumping into these guys. In short:

1. <dialog> is fun but if you apply a display property for it, it will automatically appear without being called. Be careful!!
2. Nesting CSS is fairly new, there are clashes every where. Traditional CSS is fine.
3. .aniate() in Javascript is a web APIs, it's not new but it reduces the complexity of my code and it's fun to use. Other than that I also use element.validity.valid to check the user input's validity, which is very useful.

Happy coding!