JSFiddle - React, Tailwind, and code Playground

HTML

<script src="http://www.openlayers.org/api/OpenLayers.js"></script>


    <div id="demoMap" >
    </div>

<script>
    map = new OpenLayers.Map("demoMap");
    map.addLayer(new OpenLayers.Layer.OSM());
    map.zoomToMaxExtent();
</script>

CSS

#demoMap
{
    position: relative;        
    width: 200px;
    height: 200px;
    left: 20px;
    top: 20px;
    -moz-border-radius: 15px;
    border-radius: 15px;
    border: 1px solid black;
    overflow: hidden;
}