JSFiddle - React, Tailwind, and code Playground

HTML

<html> 
    <head> 
</head> 

<body> 
    <iframe src="http://www.mobilecloud.cl/comunidad/index.php#ajax/dashboard.php" id="iframe"></iframe>
    <div id="main"> 
        <div id="heatmapArea"> 

        </div> 
    </div> 
</body> 
</html>

CSS

html, body {margin: 0px; padding: 0px;height: 100%;}

#heatmapArea{
position:relative;
float:left;
width:410px;
height:410px;
z-index:1000;
border:1px dashed black;
}

#iframe{
position:absolute;
width:100%;
height:100%;
z-index:1;
    border: 1px solid green;
}