xul-scrollbar.css

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

scrollbar {
    -moz-appearance: none !important;
    background-color: #eee !important;
    border: none !important;
    background-image: none !important;
    padding: 1px !important;
}
scrollbar:active {
    background-color: #ddd !important;
}
scrollbar[orient="vertical"] {
    width: 15px !important;
}
scrollbar[orient="horizontal"] {
    height: 15px !important;
}

thumb,
scrollbarbutton {
    background-color: -moz-Dialog !important;
    background-repeat: no-repeat !important;
    background-position: 2px 50% !important;
}
thumb {
    -moz-appearance: none !important;
    background-image: url(data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAgAAAAICAYAAADED76LAAAABGdBTUEAAK/INwWK6QAAABl0RVh0U29mdHdhcmUAQWRvYmUgSW1hZ2VSZWFkeXHJZTwAAAAkSURBVHjaYmBgYGhggAAM+v///wyMIIIQaIAqwkoPCRMAAgwAce060vmVFQEAAAAASUVORK5CYII=) !important;
    border: 1px solid ThreeDShadow !important;
    border-radius: 2px !important;
}
thumb[orient="vertical"] {
    min-height: 18px !important;
}
thumb[orient="horizontal"] {
    min-width: 18px !important;
    background-position: 50% 2px !important;
}

scrollcorner {
    -moz-appearance: none !important;
    cursor: default !important;
    background-color: -moz-Dialog !important;
    width: 13px !important;
}

scrollbarbutton {
    display: none !important;


    -moz-appearance: none !important;
    min-width: 13px !important;
    min-height: 13px !important;
    border-width: 0px !important;
}

scrollbarbutton:hover:active, scrollbarbutton[active="true"] {
    background-color: ThreeDLightShadow !important;
}
scrollbarbutton[type="increment"] {
    -moz-appearance: none !important;
}