Comment 18 for bug 238823

Better set of userChrome.css - even this one is not ideal since a menu item can be selected/highlighted even when the mouse is not hovering over it.
Leads to annoying effect of URL in wrong colour, and fllickering when moving over items. But at least this one handles dark themes.
@namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");

.ac-url-text {
    color: MenuText !important;
    background-color: Menu !important;
}
.autocomplete-richlistitem:hover .ac-url-text {
    color: HighlightText !important;
    background-color: Highlight !important;
}
.autocomplete-richlistitem {
    border-bottom: 1px solid ThreeDShadow !important;
}