* {
  margin: 0px;
  padding: 0px;
}
#body {
  margin: auto;
  margin-top: 60px;
  width: 300px;
  height: 300px;
  border: 1px solid black;
  padding: 8px;
  display: inline-block;
  background: red;
}
#purple {
  width: 200px;
  height: 200px;
  background: purple;
  margin: 40px;
  float: left;
}
#yellow {
  width: 100px;
  height: 100px;
  background: yellow;
}