.etc-main-nav--first-only > .menu > li:not(#navCategories),
.etc-main-nav--categories-only > .menu > li:not(#navCategories) {
    display: none !important;
}

.etc-main-nav[data-main-nav-mode="first-only"] > .menu > li:not(#navCategories),
.etc-main-nav[data-main-nav-mode="categories-only"] > .menu > li:not(#navCategories) {
    display: none !important;
}