/**
 * Draw a checkboard in the background
 * (useful to see the transparent part of an image)
 */
@mixin checkboard-background {
  background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAABQAAAAUAQMAAAC3R49OAAAABlBMVEX5+fn///8pDrwNAAAAFElEQVQI12NgsP/AQAz+f4CBGAwAJIIdTTn0+w0AAAAASUVORK5CYII=);
}
