i forgot to delete the four last line, i kind weird, maybe its a merging probleme as u said
1) You need to add top: 0; to your nav css:
nav {
position: fixed;
top: 0;
background: linear-gradient(-20deg, #e9defa 0%, #fbfcdb 100%);
}
2) You don't have a .main css class, its just the 'main' html container you are using, so delete the period infront of the css selector name and add a top margin to the main container to push the content down so it becomes visible:
main {
margin: 12em 0 0 0;
}
When you have a fixed navigation and use css to push the content down its just really a bit of a guessing game. Use em instead of px for the top margin because if a user zooms their browser text at least the content gets pushed down. If you use px the content wont move down and you'll find the nav, if you keep zooming the text, will eventually obscure the content.
The idea is to keep the fixed navigation as narrow in depth as is possible, yours looks a bit deep to me for a fixed nav bar.