.flex-con{
  margin: 0 16px 16px 0;
  width: 900px;
  height: 400px;
  background-color: #ddd;
  display: flex;
  flex-direction: row;
  justify-content: space-between;
}
.flex-item{
  padding: 12px;
  font-weight: bold;
  color: white;
  background-color: slateblue;
  border: 1px solid rgba(255, 255, 255, 0.2);
  min-width: 48px;
  min-height: 48px;
}
.flex-item:nth-child(3) ~ .flex-item{
  display: none;
}