JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li><span>Item 1</span><span class="num">30</span></li>
    <li><span>Item 2</span><span class="num">0</span></li>
    <li><span>Item 3</span><span class="num">20</span></li>
</ul>

CSS

.disabled {
    color: red;
}

JavaScript

$('li .num').each(function(){
    if ( $(this).text() == '0') $(this).parent().addClass('disabled');
});