diff --git a/src/sass/gtk/_common-4.0.scss b/src/sass/gtk/_common-4.0.scss
index 5e30326e..4b100348 100644
--- a/src/sass/gtk/_common-4.0.scss
+++ b/src/sass/gtk/_common-4.0.scss
@@ -1704,8 +1704,6 @@ spinbutton {
 // Comboboxes
 //
 
-dropdown > popover.menu.background > contents { padding: 0; }
-
 dropdown > button > box {
   border-spacing: $container_padding;
 }
diff --git a/src/sass/gtk/apps/_gnome-40.0.scss b/src/sass/gtk/apps/_gnome-40.0.scss
index 63918018..82f26bfa 100644
--- a/src/sass/gtk/apps/_gnome-40.0.scss
+++ b/src/sass/gtk/apps/_gnome-40.0.scss
@@ -118,6 +118,20 @@ $flap_sidebar_size: 240px;
     }
   }
 
+  .content-pane toolbarview {
+    > .top-bar,
+    > .bottom-bar {
+      .collapse-spacing {
+        headerbar {
+          > windowhandle > box {
+            padding-top: 7px;
+            padding-bottom: 7px;
+          }
+        }
+      }
+    }
+  }
+
   flap.unfolded {
     list.navigation-sidebar {
       background-color: transparent;
@@ -232,7 +246,7 @@ $flap_sidebar_size: 240px;
 #NautilusPathBar {
   background-color: $fill_color;
   border-radius: $bt_radius;
-  margin: 0 0 0 $container_padding;
+  margin: 0;
 
   #NautilusPathButton {
     margin: 0 $container_padding / 2;
@@ -251,8 +265,13 @@ $flap_sidebar_size: 240px;
   }
 
   > menubutton {
-    margin-top: 0;
-    margin-bottom: 0;
+    margin: 0;
+  }
+}
+
+#NautilusFileChooser {
+  multi-layout-view > box {
+    padding-left: $container_padding * 2;
   }
 }
 
diff --git a/src/sass/gtk/apps/_libadwaita.scss b/src/sass/gtk/apps/_libadwaita.scss
index a36184cc..bd621abd 100644
--- a/src/sass/gtk/apps/_libadwaita.scss
+++ b/src/sass/gtk/apps/_libadwaita.scss
@@ -636,9 +636,11 @@ toolbarview.undershoot-bottom scrolledwindow {
   headerbar,
   .navigation-sidebar,
   searchbar > revealer > box {
-    background-color: transparent;
-    box-shadow: none;
-    border: none;
+    &, &:backdrop {
+      background-color: transparent;
+      box-shadow: none;
+      border: none;
+    }
   }
 
   .toolbar {
@@ -656,41 +658,6 @@ toolbarview.undershoot-bottom scrolledwindow {
     }
   }
 
-  toolbarview.undershoot-top scrolledwindow {
-    @include undershoot(top, $style: 'compact');
-  }
-
-  toolbarview.undershoot-bottom scrolledwindow {
-    @include undershoot(bottom, $style: 'compact');
-  }
-
-  scrolledwindow {
-    &.undershoot-top {
-      @include undershoot(top, $style: 'compact');
-    }
-
-    &.undershoot-bottom {
-      @include undershoot(bottom, $style: 'compact');
-    }
-
-    &.undershoot-start {
-      &:dir(ltr) { @include undershoot(left, $style: 'compact'); }
-      &:dir(rtl) { @include undershoot(right, $style: 'compact'); }
-    }
-
-    &.undershoot-end {
-      &:dir(ltr) { @include undershoot(right, $style: 'compact'); }
-      &:dir(rtl) { @include undershoot(left, $style: 'compact'); }
-    }
-  }
-
-  flap,
-  leaflet,
-  navigation-view,
-  overlay-split-view {
-    @include transition-shadows($dark_borders_color);
-  }
-
   banner > revealer > widget {
     background-color: gtkmix($selected_bg_color, $dark_sidebar_bg, 30%);
     color: $text_color;
@@ -699,20 +666,6 @@ toolbarview.undershoot-bottom scrolledwindow {
       background-color: gtkmix($selected_bg_color, $dark_sidebar_bg, 30%);
     }
   }
-
-  &:dir(ltr), &.end:dir(rtl) {
-    &, banner > revealer > widget {
-      box-shadow: inset -1px 0 6px rgba(black, if($variant == 'light', 0.04, 0.08));
-      border-right: 1px solid $dark_sidebar_border;
-    }
-  }
-
-  &:dir(rtl), &.end:dir(ltr) {
-    &, banner > revealer > widget {
-      box-shadow: inset 1px 0 6px rgba(black, if($variant == 'light', 0.04, 0.08));
-      border-left: 1px solid $dark_sidebar_border;
-    }
-  }
 }
 
 /* Middle pane in three-pane setups */
@@ -726,41 +679,6 @@ toolbarview.undershoot-bottom scrolledwindow {
     transition: background-color $longer_duration $deceleration_curve;
   }
 
-  toolbarview.undershoot-top scrolledwindow {
-    @include undershoot(top, $style: 'compact');
-  }
-
-  toolbarview.undershoot-bottom scrolledwindow {
-    @include undershoot(bottom, $style: 'compact');
-  }
-
-  scrolledwindow {
-    &.undershoot-top {
-      @include undershoot(top, $style: 'compact');
-    }
-
-    &.undershoot-bottom {
-      @include undershoot(bottom, $style: 'compact');
-    }
-
-    &.undershoot-start {
-      &:dir(ltr) { @include undershoot(left, $style: 'compact'); }
-      &:dir(rtl) { @include undershoot(right, $style: 'compact'); }
-    }
-
-    &.undershoot-end {
-      &:dir(ltr) { @include undershoot(right, $style: 'compact'); }
-      &:dir(rtl) { @include undershoot(left, $style: 'compact'); }
-    }
-  }
-
-  flap,
-  leaflet,
-  navigation-view,
-  overlay-split-view {
-    @include transition-shadows($dark_borders_color);
-  }
-
   banner > revealer > widget {
     background-color: gtkmix($selected_bg_color, $base_color, 30%);
     color: $text_color;
@@ -769,20 +687,6 @@ toolbarview.undershoot-bottom scrolledwindow {
       background-color: gtkmix($selected_bg_color, $base_color, 30%);
     }
   }
-
-  &:dir(ltr), &.end:dir(rtl) {
-    &, banner > revealer > widget {
-      box-shadow: inset -1px 0 6px rgba(black, if($variant == 'light', 0.04, 0.08));
-      border-right: 1px solid $dark_sidebar_border;
-    }
-  }
-
-  &:dir(rtl), &.end:dir(ltr) {
-    &, banner > revealer > widget {
-      box-shadow: inset 1px 0 6px rgba(black, if($variant == 'light', 0.04, 0.08));
-      border-left: 1px solid $dark_sidebar_border;
-    }
-  }
 }
 
 .sidebar-pane .sidebar-pane {
@@ -793,6 +697,44 @@ toolbarview.undershoot-bottom scrolledwindow {
 .content-pane {
   background-color: $base_color;
 
+  .toolbar,
+  headerbar,
+  searchbar > revealer > box {
+    &, &:backdrop {
+      background-color: transparent;
+      box-shadow: none;
+      border: none;
+    }
+  }
+
+  toolbarview.undershoot-top scrolledwindow {
+    @include undershoot(top, $style: 'solid');
+  }
+
+  toolbarview.undershoot-bottom scrolledwindow {
+    @include undershoot(bottom, $style: 'solid');
+  }
+
+  scrolledwindow {
+    &.undershoot-top {
+      @include undershoot(top, $style: 'solid');
+    }
+
+    &.undershoot-bottom {
+      @include undershoot(bottom, $style: 'solid');
+    }
+
+    &.undershoot-start {
+      &:dir(ltr) { @include undershoot(left, $style: 'solid'); }
+      &:dir(rtl) { @include undershoot(right, $style: 'solid'); }
+    }
+
+    &.undershoot-end {
+      &:dir(ltr) { @include undershoot(right, $style: 'solid'); }
+      &:dir(rtl) { @include undershoot(left, $style: 'solid'); }
+    }
+  }
+
   toolbarview {
     &, &.view {
       background-color: transparent;
@@ -812,14 +754,55 @@ toolbarview.undershoot-bottom scrolledwindow {
   }
 }
 
-// Gnome >= 45.0
 .sidebar-pane,
-.content-pane {
-  headerbar {
-    &, &:backdrop {
-      background-color: transparent;
-      box-shadow: none;
-      border: none;
+.content-pane .sidebar-pane,
+.sidebar-pane .content-pane {
+  toolbarview.undershoot-top scrolledwindow {
+    @include undershoot(top, $style: 'solid');
+  }
+
+  toolbarview.undershoot-bottom scrolledwindow {
+    @include undershoot(bottom, $style: 'solid');
+  }
+
+  scrolledwindow {
+    &.undershoot-top {
+      @include undershoot(top, $style: 'solid');
+    }
+
+    &.undershoot-bottom {
+      @include undershoot(bottom, $style: 'solid');
+    }
+
+    &.undershoot-start {
+      &:dir(ltr) { @include undershoot(left, $style: 'solid'); }
+      &:dir(rtl) { @include undershoot(right, $style: 'solid'); }
+    }
+
+    &.undershoot-end {
+      &:dir(ltr) { @include undershoot(right, $style: 'solid'); }
+      &:dir(rtl) { @include undershoot(left, $style: 'solid'); }
+    }
+  }
+
+  flap,
+  leaflet,
+  navigation-view,
+  overlay-split-view {
+    @include transition-shadows($dark_borders_color);
+  }
+
+  &:dir(ltr), &.end:dir(rtl) {
+    &, banner > revealer > widget {
+      box-shadow: inset -1px 0 6px rgba(black, if($variant == 'light', 0.04, 0.08));
+      border-right: 1px solid $dark_sidebar_border;
+    }
+  }
+
+  &:dir(rtl), &.end:dir(ltr) {
+    &, banner > revealer > widget {
+      box-shadow: inset 1px 0 6px rgba(black, if($variant == 'light', 0.04, 0.08));
+      border-left: 1px solid $dark_sidebar_border;
     }
   }
 }