JSFiddle - React, Tailwind, and code Playground

HTML

<div id="Left" style="width: 100px; border: 1px solid #000">
    XXXXX
</div>
<button type="button" id="growBtn">Grow</button>

JavaScript

$('#growBtn').click(function() {
    var $element = $('#Left');
    $element.width($element.width() + 240);
});