JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li><span>fnord</span>
        <ul>
            <li><span>baz</span></li>
            <li><span>foo</span>
                <ul>
                    <li><span>baz</span></li>
                    <li><span>foo</span></li>
                </ul>
            </li>
        </ul>
    </li>
    <li><span>fnord</span>
        <ul>
            <li><span>baz</span></li>
            <li><span>foo</span>
                <ul>
                    <li><span>baz</span></li>
                    <li><span>foo</span></li>
                </ul>
            </li>
        </ul>
    </li>
</ul>

CSS

li>span:hover {
    background-color: lightgray;
}

li>span:hover {
    font-weight: bold;    
}