.site-map .expandable.collapsed {
    background-image: url('/Content/images/folder-expandable-collapsed.png') !important;    
    background-repeat: no-repeat;
    padding-left: 20px;
}

.site-map .expandable.expanded {
    background-image: url('/Content/images/folder-expandable-expanded.png') !important;    
    background-repeat: no-repeat;
    padding-left: 20px;
}

    .site-map .expandable.collapsed > ul {
        display: none;
    }

    .site-map .expandable.expanded > ul {
        display: block;
    }