JSFiddle - React, Tailwind, and code Playground

HTML

<nav class="nav">    
    <ul class="nav-list">
        <li><a href="#">Menu 1</a></li>
        <li><a href="#">Menu 2</a></li>
        <li><a href="#">Menu 3</a></li>
        <li><a href="#">Menu 4</a></li>
    </ul>
</nav>

CSS

.nav {
    background-color: #eee;
    text-align: center;
}

.nav-list {
    list-style: none;
    padding: 10px 0;
}

.nav-list li {
    display: inline-block;
}

.nav-list li a {
    display: block;
    position: relative;
    padding: 0 20px;
    text-decoration: none;
    color: black;
}

.nav-list li a:hover {
    color: grey;
}

/* left position is offset by -4px due to inline-blocks retaining whitespace in HTML, why most use float: left. */
.nav-list li a:after {
    content: "|";
    position: absolute;
    top: 0;
    left: 0;
    color: red;
}

.nav-list li:first-child a:after { /* first-child for IE8 support */
    display: none;
}