.item {
  width: 100%
}

.container {
  display: flex;
  flex-wrap: wrap;
}

.container > div {
  flex: 50%; /* or - flex: 0 50% - or - flex-basis: 50% - */
  /*demo*/
  box-shadow: 0 0 0 1px black;
  margin-bottom: 10px;
}
/////////////html

  
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