justify-content: flex-end
flex item 1
flex item 2
flex item 3
flex item 4
justify-content: center
flex item 1
flex item 2
flex item 3
flex item 4
justify-content: space-between
flex item 1
flex item 2
flex item 3
flex item 4
justify-content: space-around
flex item 1
flex item 2
flex item 3
flex item 4