JSFiddle - React, Tailwind, and code Playground

HTML

<ul id="algo">
    <li>hola</li>
    <li>soy</li>
    <li>una
        <ul>
            <li>lista</li>
            <li>html</li>
        </ul>
    </li>
    <li>aburrida</li>
</ul>

CSS

ul#algo > li {
    font-weight: bold;
    border: 1px solid red;
}