Specifying base url for css

No, there isn't. I suggest to place the CSS images in at least the same level as the CSS file so that you don't need to go backwards in the path. E.g. /css folder for CSS files and /css/images folder for CSS images. Then you can consistently use url('images/name.ext') for CSS images. This way you can place the root /css folder practically everywhere without fiddling with the image URL's.