hamburger($size = 30px, $size-inner-width = 70%, $size-inner-height = 2px, $size-inner-offset = 8px)
  square($size)
  &__inner,
  &__inner:before,
  &__inner:after
    background: #fff
    display: block
    position: absolute
    height: $size-inner-height
  &__inner
    width: $size-inner-width
    left: 50%
    top: 50%
    transform: translate(-50%, -50%)
  &__inner:before,
  &__inner:after
    content: ''
    width: 100%
  &__inner:before
    bottom: $size-inner-offset
  &__inner:after
    top: $size-inner-offset