.nav-pills .nav-link {
    margin-bottom: 0.5rem;
    border-radius: 0;
    border: 1px solid #000;
    background-color: #ddd;
    color: #333;
    text-align: center;
}

.nav-pills .nav-link:not(.active):hover {
    background-color: #fff;
    color: #000;
}

.nav-pills .nav-link.active {
    background-color: #000;
    color: #fff;
}