// retina.less // A helper mixin for applying high-resolution background images (http://www.retinajs.com) .at2x(@path, @w: auto, @h: auto) { background-image: url(@path); @at2x_path: ~`"@{path}".split('.').slice(0, "@{path}".split('.').length - 1).join(".") + "@2x" + "." + "@{path}".split('.')["@{path}".split('.').length - 1]`; @media all and (-webkit-min-device-pixel-ratio : 1.5) { background-image: url(@at2x_path); background-size: @w @h; } }