anchor.diff:    .dropzone-previews .dz-preview .dz-error-mark,
     .dropzone .dz-preview .dz-success-mark,
     .dropzone-previews .dz-preview .dz-success-mark {
  -    background-image: url("../images/spritemap@2x.png");
  +    background-image: url(<%= asset_path 'spritemap.png' %>);
       -webkit-background-size: 428px 406px;
       -moz-background-size: 428px 406px;
       background-size: 428px 406px;
  
positive.code:   -o-transition: opacity 0.4s ease-in-out;
    -ms-transition: opacity 0.4s ease-in-out;
    transition: opacity 0.4s ease-in-out;
    background-image: url("../images/spritemap.png");
    background-repeat: no-repeat;
  }
  @media all and (-webkit-min-device-pixel-ratio:1.5),(min--moz-device-pixel-ratio:1.5),(-o-min-device-pixel-ratio:1.5/1),(min-device-pixel-ratio:1.5),(min-resolution:138dpi),(min-resolution:1.5dppx) {
  
negative.code:   left: 0;
    width: 0%;
    height: 100%;
    background-image: url(<%= asset_path 'spritemap.png' %>);
    background-repeat: repeat-x;
    background-position: 0px -400px;
  }
  @media all and (-webkit-min-device-pixel-ratio:1.5),(min--moz-device-pixel-ratio:1.5),(-o-min-device-pixel-ratio:1.5/1),(min-device-pixel-ratio:1.5),(min-resolution:138dpi),(min-resolution:1.5dppx) {
    .dropzone .dz-preview .dz-progress .dz-upload,
    .dropzone-previews .dz-preview .dz-progress .dz-upload {
      background-image: url(<%= asset_path 'spritemap.png' %>);
      -webkit-background-size: 428px 406px;
      -moz-background-size: 428px 406px;
      background-size: 428px 406px;
  