.summit_menu li {
    display: inline;
    list-style: none;
}

.summit_menu li a {
    color: #ffffff; 
    font-weight: 600; 
    padding: 0px 15px; 
    text-decoration: none;
    line-height: 44px;
}

@media screen and (max-width:480px){
    .summit_menu li{
        display:block;
        border-top: 1px solid #00677c;
    }
}