<div class="card">
  text
</div>

* {
  box-sizing: border-box;
}

.card {
  position: relative;
  width: 400px;
  height: 300px;
  padding: 24px;
  border-radius: 12px;
  background-color: #d0d0d0;
  z-index: 0;
}

.card::before {
  display: block;
  content: '';
  position: absolute;
  left: 12px;
  right: 12px;
  top: 12px;
  bottom: 12px;
  border-radius: 2px;
  background-color: #fff;
  z-index: -1;
}