// Define vertical, horizontal, or both position
=center($position)
  position: absolute

  @if $position == 'vertical'
    top: 50%
    -webkit-transform: translateY(-50%)
    -ms-transform: translateY(-50%)
    transform: translateY(-50%)

  @else if $position == 'horizontal'
    left: 50%
    -webkit-transform: translateX(-50%)
    -ms-transform: translateX(-50%)
    transform: translate(-50%)

  @else if $position == 'both'
    top: 50%
    left: 50%
    -webkit-transform: translate(-50%, -50%)
    -ms-transform: translate(-50%, -50%)
    transform: translate(-50%, -50%)