JSFiddle - React, Tailwind, and code Playground

HTML

<div id="block"></div>

CSS

#block{
	position:absolute;
	top:0;
	left:0;
	width:20px;
	height:20px;
	background:#000;
}

JavaScript

(function forward() {
    $('#block').animate({
        marginLeft: 100
    }, 1000, function() {
        $(this).animate({
            marginLeft: 0
        }, 1000, forward)
    });
})();