JSFiddle - React, Tailwind, and code Playground

HTML

<div class="block">
  <div class="block__item"></div>
</div>

CSS

.block {
  width: 100px;
  height: 100px;
  filter: drop-shadow(-1px 6px 3px rgba(50, 50, 0, 0.5));
}
.block__item {
  width: 100%;
  height: 100%;
  box-shadow: 10px 10px 5px 0px rgba(0,0,0,0.75);
  clip-path: polygon(0 0, 80% 0%, 100% 20%, 100% 100%, 20% 100%, 0% 80%);
  background: #000;
}