Creative Single Page Site / CSS Grid, Mobile-first, Sass, Vanilla JS

Hello! Well, this almost drove me crazy :D I spend few days thinking about the layout. I couldn't decide if I should use CSS Grid or Flexbox. First I try to use Flexbox, but when I finished mobile view I started again with Grid. Positioning was little bit tricky, but I made it. But then, I opened it in Chrome :D and everything was broken. I used properties like grid-template-columns: subgrid, padding-inline, padding-block, margin-inline etc. And this is not supported in some browsers - so I recreated it again. Please, look at my solution and tell me, what I should improve. I always have a problem with semantic html. Have a nice day and Happy coding! 👋👩‍🦰