auto
    normal
    stretch
    stretch
    stretch
    left
    right
    start
    center
    end
    self-start
    self-end
    flex-start
    flex-end
    float left
    float right
    self-start (rtl)
    self-end (rtl)
    start (rtl)
    end (rtl)
    end parent
      
    absolute child
    absolute parent