JSFiddle - React, Tailwind, and code Playground

HTML

<div id="page">
    <!--<div class="article"></div>
    <div class="article"></div>-->
    <img src="http://goo.gl/sLMMQ" />
    <img src="http://goo.gl/sLMMQ" />
</div>

CSS

#page {
    background:pink;
    width:400px;
    height:200px;
}
.article,img {
    margin-left:16.66%;
    width:33.33%;
    height:100%;
    background:black;
    opacity:0.5;
    float:left;
}
.article{background:url(http://goo.gl/sLMMQ);background-size:100% 100%;}

JavaScript

var number = 0;

function aa() {
    $('#page').animate({
        width: number
    }, {
        duration: 500,
        complete: function () {
            if (number == 0) {
                number = 400;
            } else {
                number = 0;
            }
            aa();
        }
    });
}

aa();