JSFiddle - React, Tailwind, and code Playground

HTML

<div id="menu">
    <ul>
        <a href="#"><li>Menu 1</li></a>
        <a href="#"><li>Menu 2</li></a>
        <a href="#"><li>Menu 3</li></a>
        <a href="#"><li>Menu 4</li></a>
        <a href="#"><li>Menu 5</li></a>
        <a href="#"><li>Menu 6</li></a> 
    </ul>
</div>

CSS

a {
    font-family: verdana;
    color: #fff;
    font-size: 11px;   
}

a:hover {
    color: #cff;    
}
#menu {
    
    background: #666;
    height: 30px;
    width: 377px; 
    transition:height 0.5s;
    -webkit-transition:height 0.5s;
}

#menu:hover {
     height: 200px;     
}

ul {    
    padding: 0; margin: 0;
    padding-right: 10px;
    position: absolute;    
}

ul li {
    float: left;
    display:block;
    padding: 10px;
    margin: 0;
    background: #333;
    border-right: 1px solid #666
}