--- a/toolkit/themes/windows/global/button.css
+++ b/toolkit/themes/windows/global/button.css
@@ -7,17 +7,17 @@
   ======================================================================= */
 
 @namespace url("http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul");
 
 /* :::::::::: button :::::::::: */
 
 button {
   -moz-appearance: button;
-  margin: 1px 5px 2px 5px;
+  margin: 1px 5px 2px;
   min-width: 6.3em;
   color: ButtonText;
   text-shadow: none;
 }
 
 .button-box {
   border: 1px solid transparent;
   padding-top: 1px;
@@ -50,41 +50,36 @@ button:-moz-focusring > .button-box {
     button:-moz-any([default="true"],:hover,:focus):not(:-moz-any(:active,[disabled="true"],[open="true"],[checked="true"])) {
       color: HighlightText;
     }
   }
 }
 
 /* .......... active/open/checked state .......... */
 
-button:hover:active > .button-box:-moz-system-metric(windows-classic),
-button[open="true"] > .button-box:-moz-system-metric(windows-classic),
-button[checked="true"] > .button-box:-moz-system-metric(windows-classic) {
-  padding-top: 2px;
-  padding-bottom: 1px;
-  padding-inline-start: 4px;
-  padding-inline-end: 3px;
+@media (-moz-windows-classic) {
+  button:-moz-any(:hover:active,[open="true"],[checked="true"]):not([disabled="true"]) > .button-box {
+    padding-top: 2px;
+    padding-bottom: 1px;
+    padding-inline-start: 4px;
+    padding-inline-end: 3px;
+  }
 }
 
 /* .......... disabled state .......... */
 
 button[disabled="true"] {
   color: GrayText;
 }
 
-button[disabled="true"]:-moz-system-metric(windows-classic) {
-  color: ThreeDShadow;
-  text-shadow: 1px 1px ThreeDHighlight;
-}
-
-button[disabled="true"] > .button-box {
-  padding-top: 1px !important;
-  padding-bottom: 2px !important;
-  padding-inline-start: 3px !important;
-  padding-inline-end: 4px !important;
+@media (-moz-windows-classic) {
+  button[disabled="true"] {
+    color: ThreeDShadow;
+    text-shadow: 1px 1px ThreeDHighlight;
+  }
 }
 
 /* ::::: menu/menu-button buttons ::::: */
 
 button[type="menu-button"] {
   margin: 0;
 }