responsive layout with CSS grid and flexbox

Hello guys, this is my very first CSS grid website, and there are lots of abnormalities. firstly, When I tried to inspect it in mobile view, the top section of my website was cut off, I tried the min-height property but it's still not working. Secondly if there are better ways to write the codes, please let me know. So, guys please I need your reviews, it will go a long way in helping me improve in CSS grid. Thanks, in anticipation.