section {
  display: flex;
  flex-direction: row;
}

red {
  width: 125px;
  height:125px;
  background-color: #FF0000
}

blue {
  width: 125px;
  height:125px;
  background-color: #0000FF
}

green {
  width: 125px;
  height:125px;
  background-color: #008000
}