JSFiddle - React, Tailwind, and code Playground
HTML
<html>
<body>
<div id="wrap">
<div class="button">Click</div>
<div class="banner">Banner</div>
</div>
</body>
</html>
CSS
#wrap{position: relative;height:200px}
.button{background:red;}
.banner{background:blue;width:100%;height:20px;position:absolute;bottom:0px;left:0px;}
JavaScript
$(document).ready(function(){
$('.button').click(function(){
$('.banner').slideToggle();
});
});