update

src/sass/gtk/_common-3.0.scss

@@ -1866,10 +1866,14 @@ actionbar {
   }
 }
 
-.background:not(.unified) .titlebar {
+.background:not(.unified) {
+  .titlebar {
     &, & headerbar { box-shadow: inset 0 1px $highlight_color; }
   }
 
+  stack.titlebar { box-shadow: none; }
+}
+
 window.background.csd.unified {
   > deck > box.vertical > stack > headerbar.titlebar.windowhandle {
     > box > separator { background: none; }
@@ -2547,7 +2551,7 @@ notebook {
       @extend %tabs_tab;
 
       // close button
-      button.flat {
+      button.flat, button.close-button {
         min-height: $small_size;
         min-width: $small_size;
         border-radius: 3px;

src/sass/gtk/apps/_gnome-3.22.scss

@@ -1334,8 +1334,10 @@ button.documents-favorite:active:hover {
 //
 // Gnome Tweak Tool ( Gnome tweaks )
 //
-
-hdyleaflet, leaflet, box.horizontal > stack.background {
+window.background.csd {
+  > hdyleaflet,
+  > leaflet,
+  > box.horizontal > stack.background {
     frame > border { border: none; }
 
     frame:not(.view) list:not(.contacts-contact-list) { // Don't set this to Gnome-Contacts
@@ -1382,6 +1384,7 @@ hdyleaflet, leaflet, box.horizontal > stack.background {
       }
     }
   }
+}
 
 list {
   &.tweak-group {
@@ -1639,7 +1642,7 @@ window#gnome-system-monitor.background.csd {
 // Gnome-sound-recorder
 //
 
-stack {
+window.background.csd > stack {
   > grid.vertical {
     > scrolledwindow {
       border: none;
@@ -1831,7 +1834,6 @@ popover.background:not(.emoji-picker) > box.vertical > scrolledwindow {
 
 // popover for bookmarks
 popover.background:not(.emoji-picker) > box.vertical > stack > box.vertical {
-
   scrolledwindow > viewport.frame {
     border: 1px solid $borders_color;
 
@@ -2795,6 +2797,41 @@ window#GearyMainWindow.background.csd { // <= 3.32
 }
 
 
+//
+// Gnome-Box
+//
+
+window.background.csd {
+  > overlay > stack.content-bg {
+    background-color: transparent;
+    border-radius: 0 0 $wm_radius $wm_radius;
+
+    > notebook.frame {
+      border: none;
+
+      > stack {
+        border-radius: 0 0 $wm_radius $wm_radius;
+
+        > box.transparent-bg > scrolledwindow > viewport.frame > grid > stack > box {
+          > frame {
+             > border {
+              border: 1px solid $borders_color;
+              border-bottom: none;
+              border-radius: $bt_radius $bt_radius 0 0;
+            }
+
+            > stack > list {
+              border-radius: $bt_radius $bt_radius 0 0;
+            }
+          }
+
+          > toolbar.inline-toolbar { border-top: 1px solid $borders_color; }
+        }
+      }
+    }
+  }
+}
+
 //
 // Dialogs
 //

src/sass/gtk/apps/_misc.scss

@@ -438,7 +438,13 @@ toolbar#SubToolBox {
   }
 }
 
+box#SubToolbox {
+  background-color: $base_color;
+}
+
 widget#ToolboxCommon {
+  background-color: $base_color;
+
   button.flat {
     &:active {
       background-color: rgba($fg_color, 0.25);
@@ -463,6 +469,46 @@ box#DesktopStatusBar {
   }
 }
 
+scrolledwindow#DialogNotebook {
+  > viewport.frame > notebook.frame {
+    border: 1px solid $borders_color;
+
+    button.close-button {
+      margin-top: 4px;
+      margin-bottom: 4px;
+      border-radius: $circular_radius;
+
+      &, &:hover, &:active { background-color: transparent; }
+    }
+
+    notebook.frame { margin-top: -1px; }
+  }
+}
+
+grid#CanvasGrid {
+  .background & > button:not(.flat) {
+    @extend %flat_button;
+    border-radius: 3px;
+
+    &:active {
+      background-color: rgba($fg_color, 0.25);
+    }
+
+    &:checked {
+      background-color: rgba($fg_color, 0.15);
+    }
+  }
+}
+
+dialog.background {
+  > box.dialog-vbox > filechooser {
+    > actionbar > revealer > box > box > box > combobox {
+      margin-top: 24px;
+      margin-bottom: 24px;
+    }
+  }
+}
+
 //
 // Synaptic
 //