Building Blocks

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<style>
  body {
    background: #f3ac3c;
    display: grid;
    place-items: center;
  }
  div {
    width: 150px;
    height: 50px;
    background: #1a4341;
    position: absolute;
  }

  div:nth-child(3) {
    width: 70px;
    height: 70px;
    background: #f3ac3c;
    border-radius: 10px;
    box-shadow:
      30px 30px #1a4341,
      -30px -30px #1a4341;
  }

  div:nth-child(1) {
    translate: -60px -60px;
    border-radius: 10px 10px 10px 0;
  }
  div:nth-child(2) {
    translate: 60px 60px;
    border-radius: 10px 0 10px 10px;
  }
  div:nth-child(4) {
    translate: 85px 10px;
    border-radius: 10px 10px 0 0;
    width: 100px;
  }
  div:nth-child(5) {
    translate: -85.5px -10px;
    border-radius: 0 0 10px 10px;
    width: 100px;
  }
</style>