JSFiddle - React, Tailwind, and code Playground

HTML

<link rel="stylesheet" href="http://ajax.googleapis.com/ajax/libs/jqueryui/1.7.0/themes/base/jquery-ui.css">
<div id="cont1">
    <div class="elem">foo</div>
</div>
<div id="cont2">
    <div class="elem">bar</div>
</div>

CSS

#cont1, #cont2
{
    height:250px;             
    width:500px;             
    border:1px solid;
    position:absolute;
    left:10px;
}
#cont1 {top:10px}
#cont2 {top:260px;}
.elem         
{
    position:absolute;
    background-color:#f60;
    display: block;
}

JavaScript

$(".elem").each(function() {
    $(this).resizable({ containment: 'parent' });
});