[Gtk-3.20][Gtk-3.22] GtkCalendar under popover menu

src/gtk-3.20/scss/widgets/_menu.scss

@@ -1,6 +1,32 @@
 @import "entry";
 
 
+
+@mixin menu_calendar($bg, $fg) {
+    color: $fg;
+
+    &.header {
+        border-bottom: 1px solid shade($bg, ($contrast + .1));
+        border-radius: 0;
+
+        &:backdrop { border-color: shade($bg, ($contrast + .1)); }
+    }
+
+    &.button {
+        @extend %undecorated_button;
+        color: alpha($fg, .55);
+
+        &:hover {
+            @extend %undecorated_button;
+            color: $fg;
+        }
+    }
+
+    &:indeterminate,
+    &:indeterminate:backdrop { color: mix($fg, $bg, .5); }
+}
+
+
 /*********
  ! Menubar
 **********/
@@ -115,31 +141,7 @@
                 }
             }
 
-            calendar {
+            calendar { @include menu_calendar($menu_bg_color, $menu_fg_color); }
-                color: $menu_fg_color;
-
-                &.header {
-                    border-bottom: 1px solid shade($menu_bg_color, ($contrast + .1));
-                    border-radius: 0;
-
-                    &:backdrop { border-color: shade($menu_bg_color, ($contrast + .1)); }
-                }
-
-                &.button {
-                    @extend %undecorated_button;
-
-                    color: alpha($menu_fg_color, .55);
-
-                    &:hover {
-                        @extend %undecorated_button;
-
-                        color: $menu_fg_color;
-                    }
-                }
-
-                &:indeterminate,
-                &:indeterminate:backdrop { color: mix($menu_fg_color, $menu_bg_color, .5); }
-            }
 
             // avoids labels color being overridden, see
             // https://bugzilla.gnome.org/show_bug.cgi?id=767058
@@ -276,6 +278,8 @@
 
         button { @include button($menu_bg_color, $menu_fg_color); }
 
+        calendar { @include menu_calendar($menu_bg_color, $menu_fg_color); }
+
         > list, > .view, > toolbar {
             border-style: none;
             background-color: transparent;