Index: wp-includes/css/admin-bar.css
===================================================================
--- wp-includes/css/admin-bar.css	(revision 22265)
+++ wp-includes/css/admin-bar.css	(working copy)
@@ -583,7 +583,7 @@
 /**
  * Retina display 2x icons
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 	#wpadminbar .menupop .menupop > .ab-item,
 	#wpadminbar .ab-top-secondary .menupop .menupop > .ab-item,
 	#wpadminbar #adminbarsearch .adminbar-input,
Index: wp-includes/css/wp-pointer.css
===================================================================
--- wp-includes/css/wp-pointer.css	(revision 22265)
+++ wp-includes/css/wp-pointer.css	(working copy)
@@ -189,7 +189,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.wp-pointer-buttons a.close:before {
 		background-image: url('../images/xit-2x.gif');
Index: wp-includes/css/editor.css
===================================================================
--- wp-includes/css/editor.css	(revision 22265)
+++ wp-includes/css/editor.css	(working copy)
@@ -2021,7 +2021,7 @@
 
 
 /* HiDPI */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 	.wp_themeSkin span.mce_undo,
 	.wp_themeSkin span.mce_redo,
 	.wp_themeSkin span.mce_bullist,
Index: wp-admin/css/colors-fresh.css
===================================================================
--- wp-admin/css/colors-fresh.css	(revision 22265)
+++ wp-admin/css/colors-fresh.css	(working copy)
@@ -1894,7 +1894,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.curtime #timestamp {
 		background-image: url("../images/date-button-2x.gif?ver=20120916");
Index: wp-admin/css/wp-admin-rtl.css
===================================================================
--- wp-admin/css/wp-admin-rtl.css	(revision 22265)
+++ wp-admin/css/wp-admin-rtl.css	(working copy)
@@ -1581,7 +1581,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.wp-full-overlay .collapse-sidebar-arrow {
 		background-image: url('../images/arrows-2x.png');
Index: wp-admin/css/wp-admin.css
===================================================================
--- wp-admin/css/wp-admin.css	(revision 22265)
+++ wp-admin/css/wp-admin.css	(working copy)
@@ -2324,7 +2324,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.welcome-panel .welcome-panel-close:before {
 		background-image: url('../images/xit-2x.gif');
@@ -4068,7 +4068,7 @@
 	margin: 5px 5px 0;
 }
 
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 	.spinner,
 	.imgedit-wait,
 	.customize-loading #customize-container {
@@ -4273,7 +4273,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 	.imgedit-crop,
 	.imgedit-rleft,
 	.imgedit-rright,
@@ -5558,7 +5558,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.wp-full-overlay .collapse-sidebar-arrow {
 	 	background-image: url('../images/arrows-2x.png');
@@ -6500,7 +6500,7 @@
 	display: block;
 }
 
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 	.login h1 a {
 		background-image: url('../images/wordpress-logo-2x.png?ver=20120412');
 		background-size: 274px 63px;
@@ -8277,7 +8277,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.press-this .tagchecklist span a {
 	 	background-image: url('../images/xit-2x.gif');
Index: wp-admin/css/media.css
===================================================================
--- wp-admin/css/media.css	(revision 22265)
+++ wp-admin/css/media.css	(working copy)
@@ -331,7 +331,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.image-align-none-label {
 		background-image: url("../images/align-none-2x.png?ver=20120916");
Index: wp-admin/css/colors-classic.css
===================================================================
--- wp-admin/css/colors-classic.css	(revision 22265)
+++ wp-admin/css/colors-classic.css	(working copy)
@@ -2011,7 +2011,7 @@
 /**
  * HiDPI Displays
  */
-@media only screen and (-webkit-min-device-pixel-ratio: 1.5) {
+@media only screen and (min--moz-device-pixel-ratio: 1.5), only screen and (-o-min-device-pixel-ratio: 3/2), only screen and (-webkit-min-resolution: 1.5dppx), only screen and (min-resolution: 1.5dppx) {
 
 	.curtime #timestamp {
 		background-image: url("../images/date-button-2x.gif?ver=20120916");