@-moz-document url("chrome://browser/content/browser.xul") {

#tb-uppity {
list-style-image: url("moz-icon://stock/gtk-go-up?size=toolbar") !important;
}

toolbar[iconsize="small"] #tb-uppity {
list-style-image: url("moz-icon://stock/gtk-go-up?size=menu") !important;
}

#tb-uppity[disabled] {
list-style-image: url("moz-icon://stock/gtk-go-up?size=toolbar&state=disabled") !important;
}

toolbar[iconsize="small"] #tb-uppity[disabled] {
list-style-image: url("moz-icon://stock/gtk-go-up?size=menu&state=disabled") !important;
}

}