GeneratePress: Menu Underline Effects

@media (min-width: 769px) {
    .main-navigation .menu > .menu-item > a::after {
        content: "";
        position: absolute;
        right: 0;
        left: 50%;
        bottom: 15px;
        -webkit-transform: translateX(-50%);
        transform: translateX(-50%);
        display: block;
        width: 0;
        height: 2px;
        background-color: currentColor;
        transition: 0.3s width ease;
    }
    .main-navigation .menu > .menu-item.current-menu-item > a::after,
    .main-navigation .menu > .menu-item.current-menu-ancestor > a::after,
    .main-navigation .menu > .menu-item > a:hover::after {
        width: 50%;
    }
}