$background: (
  'background-attachment': (
    'values': (
      bg-fixed: fixed,
      bg-local: local,
      bg-scroll: scroll
    )
  ),
  'background-clip': (
    'values': (
      bg-clip-border: border-box,
      bg-clip-padding: padding-box,
      bg-clip-content: content-box,
      bg-clip-text: text
    )
  ),
  'background-origin': (
    'values': (
      bg-origin-border: border-box,
      bg-origin-padding: padding-box,
      bg-origin-content: content-box
    )
  ),
  'background-position': (
    'values': (
      bg-center: center,
      bg-top: top,
      bg-top-right: top right,
      bg-right: right,
      bg-right-bottom: right bottom,
      bg-bottom: bottom,
      bg-left-bottom: left bottom,
      bg-left: left,
      bg-left-top: left top
    )
  ),
  'background-repeat': (
    'values': (
      bg-repeat: repeat,
      bg-no-repeat: no-repeat,
      bg-repeat-x: repeat-x,
      bg-repeat-y: repeat-y,
      bg-repeat-round: round,
      bg-repeat-space: space
    )
  ),
  'background-size': (
    'values': (
      bg-auto: auto,
      bg-cover: cover,
      bg-contain: contain
    )
  )
);