// Responsive image
//
// Keep images from scaling beyond the width of their parents.
@mixin img-responsive($display: block) {
  display: $display;
  max-width: 100%; // Part 1: Set a maximum relative to the parent
  height: auto; // Part 2: Scale the height according to the width, otherwise you get stretching
}

// Retina image
//
// Short retina mixin for setting background-image and -size. Note that the
// spelling of `min--moz-device-pixel-ratio` is intentional.
@mixin img-retina($file-1x, $file-2x, $width-1x, $height-1x) {
  background-image: url(if(
    $bootstrap-sass-asset-helper,
    twbs-image-path('#{$file-1x}'),
    '#{$file-1x}'
  ));

  @media only screen and (-webkit-min-device-pixel-ratio: 2),
    only screen and (-o-min-device-pixel-ratio: 2/1),
    only screen and (min-resolution: 192dpi),
    only screen and (min-resolution: 2dppx) {
    background-image: url(if(
      $bootstrap-sass-asset-helper,
      twbs-image-path('#{$file-2x}'),
      '#{$file-2x}'
    ));
    background-size: $width-1x $height-1x;
  }
}