li
{
    margin:5px;
    border:5px solid transparent;
    border-top:0px;
    border-left:0px;
    border-right:0px;
}
div>ul>li:hover
{
    margin:5px;
    border:5px solid white;
    border-top:0px;
    border-left:0px;
    border-right:0px;
}
li>ul>li:hover
{
    margin:5px;
    border-bottom:5px solid transparent;
    color:white;
}
.nav-link
{
    color:white;
    font-weight: bold;
    font-size:23px;
}