Thanks, this worked:
#top_section {
background: linear-gradient(to bottom, rgba(0,0,0,0) 125px, rgba(210,210,210,1) 220px), url(../../images/bg_ep.png), #E6E6E6;
background-position: center;
box-shadow: 0 1px 4px #666;
border-top: 1px solid #5BA9D9;
border-bottom: 3px solid #5BA9D9;
}
But only when the header is not collapsed. When it is, the fading disappears. That's why I asked about the div.
I tried this:
.nav_menu {
background: linear-gradient(to bottom, rgba(0,0,0,0) 0px, rgba(210,210,210,1) 95px), url(../../images/bg_ep.png);
}
and this:
#nav_menu {
background: linear-gradient(to bottom, rgba(0,0,0,0) 0px, rgba(210,210,210,1) 95px), url(../../images/bg_ep.png);
}
Nothing happened. I am really not good at this!