Edit in JSFiddle

.container {
  width: 800px;
  display: flex;
  justify-content: space-between;
}

.item {
  display: block;
}

.container-t{
  display: table;
  width: 800px;
}

.item-t {
  display: table-cell;
}

.spacer {
  display: table-cell;
  width: 33.33%;
}