JSFiddle - React, Tailwind, and code Playground

HTML

<div id="panel">
        <div id="slideDownPanel">
    <img src="http://fusedfilm.com/wp-content/uploads/2009/08/spider-man.jpg" alt="dummy image" />
        </div>
</div>

CSS

body {background-color: #000}
#panel {
    width: 430px;
    height: 320px;
    position: absolute;
    top: 0px;
    left: 0px; 
}
#slideDownPanel
{
    width: 430px;
    height: 320px;
    position: relative;
    top: -320px;
}

JavaScript

$("#slideDownPanel").animate({
    top: 0
}, 2000);