<!DOCTYPE html>
<title>CSS Backdrop Filters Animation: Drop Shadow Reference</title>
<link rel="author" title="Mason Freed" href="mailto:masonfreed@chromium.org">
<style>
    .square {
        position: absolute;
        width: 100px;
        height: 100px;
        top: 100px;
        left: 100px;
        background: blue;
    }
    .filt {
        position: absolute;
        width: 200px;
        height: 200px;
        top: 50px;
        left: 50px;
        backdrop-filter: drop-shadow(15px 15px 0px rgba(0, 0, 0, 0.5));
    }
    .greenbox {
        position: absolute;
        width: 50px;
        height: 50px;
        top: 75px;
        left: 75px;
        background: green;
    }
</style>
<p>You should see a blue rectangle in top of a gray one, with a green box on top.</p>
<div class="square"></div>
<div class="filt">
    <div class="greenbox"></div>
</div>