JSFiddle - React, Tailwind, and code Playground

HTML

<div id="slideout">
    <div id="slidecontent">
        I am the content. I am the king!
    </div>
    <div id="clickme">
    </div>
</div>

CSS

#slideout {
    background: #f4f4f4;
    position: absolute;
    width: 400px;
    height: 150px;
    top: 30%;
    left:-400px;
    padding-left: 0;
    z-index: 50;
}
    
#clickme {
    position: absolute;
    top: 0; right: -20px;
    height: 20px;
    width: 20px;
    background: tomato;
    cursor: pointer;
}

#slidecontent {
    float:left;
    padding: 35px;
}

.overlay {
    background-color: #000;
    bottom: 0;
    display: none;
    left: 0;
    opacity: 0.5;
    filter: alpha(opacity = 50); /* IE7 & 8 */
    position: fixed;
    right: 0;
    top: 0;
    z-index: 49;
}

JavaScript

$(function () {

    $("#clickme").click(function () {
        if($(this).parent().hasClass("popped")){
            $(this).parent().animate({left:'-400px'}, {queue: false, duration: 500}).removeClass("popped");
            
        }else {
            $(this).parent().animate({left: "0px" }, {queue: false, duration: 500}).addClass("popped");
        }
    });
});