Before after weird code

Hello
please help to fix this issues

I see grey line above my header and I don't know how to remove it
I see the code but can't find it in theme css
body:not(.custom-background-image)::before, body:not(.custom-background-image)::after {
background: inherit;
content: "";
display: block;
height: 21px;
left: 0;
position: fixed;
width: 100%;
z-index: 99;
}

Also very strange icons in my menu
others pages work fine - I have problems only with home page