<!DOCTYPE html>
<html>
<head>
<style>
.box {
margin: 50px;
height: 150px;
width: 150px;
}
.shadow {
margin: 20px;
height: 300px;
width: 300px;
background-color: silver;
border: 1px solid black;
filter: drop-shadow(10px 10px 10px blue);
}
</style>
</head>
<body>
<div class="shadow">
</div>
</body>
</html>