<!DOCTYPE HTML>
<style>

#thediv {
  width: 400px;
  height: 250px;
  position: absolute;
  top: -500px;
  left: -500px;
  box-shadow: 540px 540px 10.5px black;
}

#blankdiv {
  width: 400px;
  height: 250px;
  background-color: white;
  position: absolute;
  top: 40px;
  left: 40px;
}
</style>

<div id="thediv">&nbsp;</div> 
<div id="blankdiv">&nbsp;</div>