JSFiddle - React, Tailwind, and code Playground

HTML

<div>Test</div>
<div>test</div>
<div>blah</div>
<div>more blah</div>

CSS

div {
    padding: 10px; margin: 4px; border: solid 1px #444;
}
.bingo {
    background: maroon; color: white;
}

JavaScript

$.expr[':'].containsIgnoreCase = function (n, i, m) {
            return jQuery(n).text().toUpperCase().indexOf(m[3].toUpperCase()) >= 0;
        };
$('div:containsIgnoreCase("test")').addClass('bingo');