.main-nav{background:#1a237e}.main-nav ul{display:flex;list-style:none}.main-nav li{position:relative}.main-nav a{color:white;padding:15px;display:block}.main-nav ul ul{display:none;position:absolute;background:white}.main-nav li:hover>ul{display:block}@media(max-width:768px){.main-nav ul{flex-direction:column}}