Answers for "display flex stretch width"

flexbox stretch height

.flex-2 {
    display: flex;  
    align-items: stretch;
}

how to create seprate flex box for adding items into the box

.container {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
}

.item {
  width: 32%;
  padding-bottom: 32%; /* Same as width, sets height */
  margin-bottom: 2%; /* (100-32*3)/2 */
  position: relative;
}