aboutdialog

@namespace url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);

@-moz-document url("chrome://browser/content/aboutDialog.xul") {
    #leftBox {
        background-image: url("http://thepouar.dnsdojo.com/pouar/downloads/firefoxdiaperfur.svgz");
    }
}