nav {
    list-style-type: none;
    overflow: hidden;
    background-color: darkgray;
}


nav a {
    display: block;
    text-align: center;
    text-decoration: none;
    border-right: 1px solid #bbb;
    color: white;
    background-color: blue;
    padding: 3px;
}

nav a:hover {
    background-color: navy;
}

nav a:last-child {
    border-right: 1px solid white;
}

nav ul{
    list-style-type: none;
    display: flex;
}

nav ul ul{
    flex-direction: column;
}

nav ul ul a{
    height: 0;
    overflow: hidden;
    padding: 0;
    display: block;
}

nav ul li:hover ul a {
    height: 20px;
    display: block;
    width: 100%;
    position: relative;
}

#login {
    background-color: navy;
}