JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li><div>Row 1</div></li>
    <li><div>Row 2</div></li>
    <li>
        <ul>
            <li><div>Row 3 Col 1</div></li>
            <li><div>Row 3 Col 2</div></li>
        </ul>
    </li>
</ul>

CSS

ul { padding: 5px 3px;
    margin: 3px 0; }
li { padding: 3px 2px; background-color: #DDD; }
li:hover > div { background-color: #0F0; }