<nav>
    <ul class='main-nav'>
        <li id="logo"><a href="#">Brand</a></li>
        <li><a href="#">About</a></li>
        <li><a href="#">Projects</a></li>     
        <ul class='right-nav'>
            <li id="contact"><a href=""><i class="fas fa-envelope-square"></i> Contact</a></li>
        </ul>
    </ul>           
</nav>

nav{
    background-color: rgba(0, 0, 0, 0.75);
    font-size:1.33rem;
    position: relative;
}

#logo{
    margin-right: 3rem;
}

ul{
    display: inline-flex;
    margin-bottom:0;
    margin-top:0;
    padding:0;
    list-style-type: none;
    flex-flow:row;
    justify-content: flex-start;
    align-items: center;
}

.right-nav{
    position: absolute;
    right: 0;
}

a{
    display: inline-block;
    color: antiquewhite;
    text-decoration: none;
    padding:0.75rem 2.0rem;
}

a:hover{
    text-decoration: none;
    background-color: rgba(243,134,48,0.5); 
    color: rgb(255, 255, 255);
    font-weight: 500;
}

li{
    cursor: pointer;   
}

@media all and (max-width:600px){
    .main-nav{
        flex-direction: column;
        width: 100%;
    }

    a{
        padding: 12px 600px;
    }
    nav{
        display: flex;
        flex-flow: row wrap;
        justify-content: center;
    }

    #logo{
        margin-right: inherit;
    }

    .right-nav{
        position: unset;
    }
}