JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.8.4/themes/ui-lightness/jquery-ui.css">
<div id='outer'>
    <div id='inner'></div>
</div>

CSS

#outer {
    height: 300px;
    background: yellow;
    position:relative;
}

#inner {
    position: absolute;
    bottom: 0;
    height:0;
    width: 100%;
    background:red;
}

JavaScript

$('#inner').animate({height:'+=250'},1500);