flex: initial => flex: 0 1 auto
flex: none => flex: 0 0 auto
flex: auto => flex: 1 1 auto
flex: 0 => flex: 0 1 0
flex: 1 => flex: 1 1 0
flex: 1 0 => flex: 1 0 0
flex: 1 2 => flex: 1 2 0
flex: 1 auto => flex: 1 1 auto
flex: 1 10px => flex: 1 1 10px
flex: 1 0px => flex: 1 1 0px