JSFiddle - React, Tailwind, and code Playground

HTML

<div></div>
<p>
    <input type="button" value="Toggle Width" />
</p>

CSS

div {
    width: 0;
    height: 100px;
    background-color: #00f;
    margin-bottom: 15px;
}

JavaScript

var expanded = false;
$('input').click(function() {
    var width = $('div').width();
    if (expanded) {
        $('div').animate({
            width: '0'
        }, {
            queue: false,
            duration: (width * 10)
        });
        expanded = false;
    } else {
        $('div').animate({
            width: '100px'
        }, {
            queue: false,
            duration: (100-width) * 10
        });
        expanded = true;
    }
});