.navbar{background:#000;}
.nav-item::after{content:'';display:block;width:0px;height:2px;background:rgb(20, 20, 20);transition: 0.2s;}
.nav-item:hover::after{width:100%;}
.navbar-dark .navbar-nav .active > .nav-link, .navbar-dark .navbar-nav .nav-link.active, .navbar-dark .navbar-nav .nav-link.show, .navbar-dark .navbar-nav .show > .nav-link,.navbar-dark .navbar-nav .nav-link:focus, .navbar-dark .navbar-nav .nav-link:hover{color:rgb(30, 30, 30);}
.nav-link{padding:15px 5px;transition:0.2s;}
nav .navbar-nav li a{
  color: grey !important;
}
nav .navbar-nav li a:hover{
  color: white !important;
}