How to add a sticky header

If you need to customize your site header and make it fixed when you scroll down the page please use this CSS snippet in the designated area from   Appearance > Theme Options > Custom CSS:

#header {
    top: 0 !important;
    transform: none !important;
    background: #222 !important;
}
#logo-holder #logo .dark {
    opacity: 0 !important;
    visibility: hidden !important;
}
#logo-holder #logo .light {
    opacity: 1 !important;
    visibility: hidden !important;
}
.lines, .lines:before, .lines:after {
    color: #fff !important;
}
 Important! Because the header will always be fixed it needs to have a permanent background. Considering that the navigation menu (when opens) is dark, the only solution is to have a dark menu background, otherwise it's impossible to make it all work properly.