.navbar-nav {
    display: -ms-flexbox;
    display: flex;
    -ms-flex-direction: column;
    flex-direction: column;
    width: 100%;
    padding-left: 0;
    margin-bottom: 0;
    list-style: none;
}
.navbar-nav li:hover>.dropdown-menu {
    display: block;
    margin: 0;
    position: absolute;
    z-index: 2;
    width: 100%;
    font-size: 1.5vw;
    transition: all 0.6s cubic-bezier(0.23, 1, 0.32, 1);
}