* {
  box-sizing: border-box;
  margin: 0;
  padding: 0;
}
.parent {
  border: 2px black dotted;
  display: inline-block;
}
.box {
  display: inline-block;
  background-color: red;
  width: 100px;
  height: 100px;
}
#two {
  background-color: green;
}