// mix into the top level
=sticky-footer( !footer_height, !root_selector = "#root", !root_footer_selector = "#root_footer", !footer_selector = "#footer")
  html
    :height 100%
  body
    :height 100%
  #{!root_selector}
    :min-height 100%
    :margin-bottom  = -!footer_height
    #{!root_footer_selector}
      :height = !footer_height
  #{!footer_selector}
    :clear            both
    :position         relative
    :height         = !footer_height