@media only screen and (min-width: 768px) {
    
    header h1 {font-size: 2.85rem;}
    header h2 {font-size: 1.5rem; }
    header img {height: 100px;}
    
   .medium-6 {width: 50%;}
    
    nav button {display: none;}
    nav ul {display: block;}
    nav li {width: 25%; float: left;}
    
    
    
} /* end of media query */