// http://www.zeldman.com/2012/03/01/replacing-the-9999px-hack-new-image-replacement/
hide-text()
  text-indent: 100%
  white-space: nowrap
  overflow: hidden

// http://codepen.io/shshaw/full/gEiDt
absolute-center(width, height = width)
  // margin: auto
  // position: absolute
  // top: 50%
  // top: 0
  // left: 0
  // bottom: 0
  // right: 0
  // width: width
  // height: height
  // overflow: auto
  width: width
  height: height
  position: absolute
  top: 50%
  left: 50%
  margin-top: width * -0.5
  margin-left: height * -0.5

avoid-column-break()
  vendor("column-break-inside", avoid, only: webkit)
  page-break-inside: avoid // for firefox
  overflow: hidden // fix for firefox
  break-inside: avoid-column