Fixed xfce4 desktop issues

src/sass/gtk/apps/_xfce.scss

@@ -92,7 +92,8 @@ XfdesktopIconView.view {
 
 window#whiskermenu-window {
   border-radius: $wm_radius;
-  background-color: $bg_color;
+  background-color: transparent;
+  border: none;
 
   entry.search:focus { background-color: $base_color; }
 
@@ -100,6 +101,12 @@ window#whiskermenu-window {
   > frame > border {
     border-radius: $wm_radius;
     padding: 6px;
+    margin: 6px;
+    border: none;
+    background-color: $bg_color;
+    box-shadow: 0 3px 3px 0 $wm_shadow,
+                inset 0 0 0 1px $header_highlight,
+                $wm_outline;
   }
 
   scrolledwindow {
@@ -233,6 +240,15 @@ window.thunar {
 }
 
 
+//
+// Xfsm dialog
+//
+dialog.xfsm-logout-dialog {
+  border: 1px solid if($variant=='light', rgba(black, 0.15), rgba(black, 0.75));
+  box-shadow: none;
+}
+
+
 //
 // mousepad
 //