@media (min-width: 992px)
{
    .nav.navbar-nav .dropdown .dropdown-menu
    {
        transform-origin: top center;
        -webkit-animation: growDown 300ms ease-in-out forwards;
                animation: growDown 300ms ease-in-out forwards;
    }
}

@-webkit-keyframes growDown
{
    0%
    {
        transform: scaleY(0);
    }
    80%
    {
        transform: scaleY(1.1);
    }
    100%
    {
        transform: scaleY(1);
    }
}

@keyframes growDown
{
    0%
    {
        transform: scaleY(0);
    }
    80%
    {
        transform: scaleY(1.1);
    }
    100%
    {
        transform: scaleY(1);
    }
}