diff --git a/gtk-3.0/apps/_mate.scss b/gtk-3.0/apps/_mate.scss
index b77a7de..ad89a77 100644
--- a/gtk-3.0/apps/_mate.scss
+++ b/gtk-3.0/apps/_mate.scss
@@ -35,4 +35,25 @@ panel-toplevel.background {
     -NaTrayApplet-icon-padding: 0;
     -NaTrayApplet-icon-size: 16px;
   }
-}
\ No newline at end of file
+}
+
+//
+// Mate OSD Window
+//
+
+MsdOsdWindow.background.osd {
+    border-radius: 2px;
+    border: 1px solid $borders_color;
+  
+    .progressbar {
+      background-color: $selected_bg_color;
+      border: none;
+      border-color: $selected_bg_color;
+      border-radius: 5px;
+    }
+    .trough {
+      background-color: darken($osd_bg_color, 5%);
+      border: none;
+      border-radius: 5px;
+    }
+  }
diff --git a/gtk-3.0/gtk-dark.css b/gtk-3.0/gtk-dark.css
index ad3e3e3..bbd6aef 100755
--- a/gtk-3.0/gtk-dark.css
+++ b/gtk-3.0/gtk-dark.css
@@ -6200,6 +6200,19 @@ panel-toplevel.background na-tray-applet {
   -NaTrayApplet-icon-padding: 0;
   -NaTrayApplet-icon-size: 16px; }
 
+MsdOsdWindow.background.osd {
+  border-radius: 2px;
+  border: 1px solid rgba(238, 238, 238, 0.1); }
+  MsdOsdWindow.background.osd .progressbar {
+    background-color: #00D3A7;
+    border: none;
+    border-color: #00D3A7;
+    border-radius: 5px; }
+  MsdOsdWindow.background.osd .trough {
+    background-color: rgba(7, 8, 11, 0.98);
+    border: none;
+    border-radius: 5px; }
+
 /***********************
  * App-Specific Styles *
  ***********************/
diff --git a/gtk-3.0/gtk.css b/gtk-3.0/gtk.css
index 2c2db5e..6e94f8c 100755
--- a/gtk-3.0/gtk.css
+++ b/gtk-3.0/gtk.css
@@ -6225,6 +6225,19 @@ panel-toplevel.background na-tray-applet {
   -NaTrayApplet-icon-padding: 0;
   -NaTrayApplet-icon-size: 16px; }
 
+MsdOsdWindow.background.osd {
+  border-radius: 2px;
+  border: 1px solid rgba(0, 0, 0, 0.13); }
+  MsdOsdWindow.background.osd .progressbar {
+    background-color: #00D3A7;
+    border: none;
+    border-color: #00D3A7;
+    border-radius: 5px; }
+  MsdOsdWindow.background.osd .trough {
+    background-color: rgba(19, 25, 31, 0.98);
+    border: none;
+    border-radius: 5px; }
+
 /***********************
  * App-Specific Styles *
  ***********************/