I tryed so hard to make my code responsive... but I can't. Help!!!

Question

https://code.sololearn.com/WOoFoaEZor8K/#html

Answer 1

body {
text-align: center;
align-self: center;

align-self is flexbox selector, where is display: flex?

Max width 100% at @media? This is meaningless
@media (max-width: 100%)
Should be in px

Do not put html comment tag in css
<!--Responsive CSS-->

margin: auto 350px auto 350px; is wrong format, use margin: auto 350px;

Answer 2

https://code.sololearn.com/W3gS00IGw160/?ref=app

Answer 3

I think bootstrap is friendly and I offer it.