.container {
    width: 200px;
    height: 200px;
    position: relative;
    margin: 20px;
  }

  .box {
    width: 100%;
    height: 100%;            
    position: absolute;
    top: 0;
    left: 0;
    opacity: 1;  /* for demo purpose  */
  }

  .stack-top {
    z-index: 9;
    margin: 0px; /* for demo purpose  */
  }

  .wrapper {
    display: flex;
    flex-direction: column;
    gap: 80px;
}