JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li>Lorem ipsum dolor sit amet, consectetuer adipiscing elit.</li>
    <li>Aliquam Lorem tincidunt mauris lorem eu risus.</li>
    <li>Vestibulum auctor dapibus neque.</li>
</ul>

CSS

.look-at-me {
    background: #999;
}

JavaScript

$('li').each(function () {
    $(this).html($(this).html().replace(/Lorem/ig, "<mark>$&</mark>"));
    if ($(this).text().toLowerCase().indexOf('lorem') >= 0) $(this).addClass('look-at-me');
});