.navbar-collapse ul li {
    display: inline-block;
    position: relative;
    margin-right: 1rem;
    overflow: hidden;
}
.navbar-collapse ul li:not(.active):hover::after{
    min-height: 6px;
    opacity: 1;
    transform: translateX(-50%);
}

.navbar-collapse ul li:not(.active)::after {
    content: '';
    transition: 0.1s ease-in-out;
    opacity: 0;
    width: 100%;
    min-height: 0;
    background-color: #ff780e;
    position: absolute;
    bottom: 0;
    left: 50%;
    pointer-events: none;
}

.navbar-collapse ul li.active::after {
    content: '';
    opacity: 1;
    width: 100%;
    min-height: 6px;
    background-color: #ff780e;
    position: absolute;
    bottom: 0;
    pointer-events: none;
}