Want to Fix Header

Hello i am using the generatepress theme
now i am using thsi
`body .site.grid-container {
max-width: 100%;
}

but its not working properly
check out one site which is showing fine
https://puu.sh/GsZx1/d2d5306ae3.jpg here is the demo

now please check out mine
https://puu.sh/GsZx1/d2d5306ae3.jpg
problem is spacing also not good from the menu
and that block cover also going into right side
even i made it right.
Let me know how to fix this issue