.adm-o2k_sitecore .adm-main-menu-item-icon {
    background-image: url('/local/modules/o2k.sitecore/admin/css/o2k_logo.png');
    background-position: center 10px;
    height: 49px;
}

.adm-o2k_sitecore:hover .adm-main-menu-item-icon {
    background-position: center -38px;
    height: 49px;
}

.adm-main-menu-item-active.adm-o2k_sitecore .adm-main-menu-item-icon {
    background-position: center -38px;
    height: 49px;
}