body {
  margin: 0px;
  display: flex;
  flex-flow: row wrap;
}

.box {
  font-size: 3rem;
  color: #000;
  background-color: #fff;
  width: 9vw;
  min-width: 50px;
  height: 9vw;
  min-height: 50px;
  border: 3px #000 solid;
  margin: calc((1vw / 2) - 3px);
  display: flex;
  justify-content: center;
  align-items: center;
}

#two {
  background-color: #eee;
  position: relative;
  top: 5.8vw;
  left: 5.8vw;
}