JSFiddle - React, Tailwind, and code Playground

HTML

<ul>
    <li><span class="center">Text</span></li>
    <li><span class="center">Text big</span></li>
    <li><span class="center">Text small</span></li>
</ul>

CSS

ul li {
    width: 200px;
    background: #CCC;
}

li .center {
    background: #666;
}

JavaScript

$('li .center').each(function() {
    var width = $(this).width();
    $(this).css({"paddingLeft": (200 - width)/2 + 'px'});
});