<!doctype html>
<html lang="en">
<head>
	<style>
	p, div {
		font: 12px/1 monospace;
	}
	#region {
		width: 300px;
		height: 190px;
		border: 5px solid green;
		border-left: 100px solid green;
		border-color: darkred;
		background-color: #ddddff;
	}
	</style>
</head>
<body>
	<p>When hovering the <span style="color:green"><b>region</b></span>, the <span style="color:blue"><b>blue</b></span> box should disappear (the region's <b>flow-from</b> will change to "none")</p>
	<div id="region"></div>
</body>
</html>