Hello Craig,
This custom css usually goes with a Javascript:
@media (min-width: 979px){
.x-navbar {
background: transparent;
border: none;
box-shadow: none;
}
.x-navbar.x-navbar-solid {
border-bottom: 1px solid #ccc;
background-color: #fff;
box-shadow: 0 0.15em 0.35em 0 rgba(0,0,0,0.135);
}
}
The JS code should be added in please in the Theme Options > Global JS (http://prntscr.com/evswzb)
jQuery(document).ready(function($) {
var $body = $('body');
var $navbar = $('.x-navbar');
if ( $body.hasClass('x-navbar-fixed-top-active') && $navbar.length > 0 ) {
$(window).scroll(function() {
if ( $(this).scrollTop() >= 350 ) {
$navbar.addClass('x-navbar-solid');
} else {
$navbar.removeClass('x-navbar-solid');
}
});
}
});
And then go to Appearance > Ubermenu > Main UberMenu Configuration > Style Customizations and make sure that the ubermenu background color is set to transparent.
Hope this helps. Please let us know how it goes.