<style>
html, body {
    margin: 0;
}
</style>
<div style="clip: rect(100px,1000px,1000px,100px); position:absolute">
  <div style="filter: drop-shadow(50px 50px 20px red)">
    <div style="width:256px; height:256px; border-radius:16px; overflow:hidden">
      <div style="width:256px; height:256px; background-color:green;"></div>
    </div>
  </div>
</div>