.box.box-1
.box.box-2

.box {
  width: 100px;
  height: 50px;
  border: 2px solid black;
}

.box-1 {
  margin-bottom: 50px;
  background-color: red;
}

.box-2 {
  margin-top: 30px;
  background-color: blue;
}