JSFiddle - React, Tailwind, and code Playground

HTML

<nav>
    <ul>
        <li><a href="#">Home</a></li>
        <li><a href="#">Goods</a>
            <ul class="child">
                <li><a href="#">Apples</a></li>
                <li><a href="#">Pears</a></li>
            </ul>            
            </li>
        <li><a href="#">Contacts</a></li>
    </ul>
</nav>

CSS

ul {
    display: table;
    width: 400px;
    border: 1px solid #222;
    padding: 0;
}

li {
    position: relative;
    display: table-cell;
    background: #ffaaaa;
}

li a {
    display: block;
    color: #222;
    text-decoration: none;
    padding: 4px 12px;
    text-align: center;
}

li:hover a {
    background-color: #dd8888;
    color: #fff;
}

.child {
    display: none;
    position: absolute;
    top: 27px;
    left: 0;
    width: 160px;
}
li:hover .child {
    display: block;
}
.child li {
    display: block;
}
.child li a {
    color: #000;
    background: #ffffaa;
}
.child li:hover a {
    color: #000;
    background: #dddd99;
}

JavaScript

// во второй пункт вложено подменю