justify-content: space-around

a1 a3 a3
a1; width: 250px a2; width: 250px a3; width: 250px
a1; flex-basis: 250px a2; flex-basis: 250px a3; flex-basis: 250px
a1; width: 250px a2; width: 250px a3; width: 250px
a1; width: 250px a2; width: 250px a3; width: 250px
width: 250px width: 250px width: 250px
width: 250px; height: 30px width: 250px width: 250px

flex-grow: 1

item flex-grow: 1
flex-grow: 1 flex-grow: 1
flex-grow: 1 flex-grow: 3 flex-grow: 1

margin: auto

margin: 0 auto margin: 0 auto
margin: 0 auto margin: 0
margin: 0 margin: 0 auto
margin: auto margin: auto margin: auto margin: auto margin: auto

align-items: flex-end; justify-content: flex-end

item item

order: 1

order: 1 order: 0