:root {
    --nb-main-navigation-2-mobile-width: 100%;
}

.nb-menu-first-level-item-list.wsmenu-list {
    position: static;
}

@media screen and (max-width: 991px) {
    .nb-menu-first-level-item-list.wsmenu-list {
        position: unset;
        display: block;
        width: var(--nb-main-navigation-2-mobile-width);
        padding: 20px 15px;
        margin-left: 100vw;
    }
}