Fix #241

Author: lassekongo83

Diff for: gtk/src/adw-gtk3/gtk-3.0/_apps.scss

@@ -1129,8 +1129,39 @@ geary-conversation-viewer#conversation_viewer {
   margin: 0;
 }
 
-.geary-folder {
-  &, &:backdrop { background-color: $window_bg_color; }
+// newer versions
+.geary-main-window leaflet > leaflet > box {
+  &:first-child {
+    background-color: $sidebar_bg_color;
+    &:backdrop { background-color: $sidebar_backdrop_color; }
+  }
+}
+
+.geary-main-window leaflet > box {
+  &:first-child > .titlebar {
+    background-color: $sidebar_bg_color;
+    background-image: none;
+    border-bottom: transparent;
+    box-shadow: none;
+    &:backdrop { background-color: $sidebar_backdrop_color; }
+
+    button {
+      background-color: transparent;
+      &:hover { background-color: $titlebutton_normal_hover; }
+      &:hover:active, &:active, &:hover:checked, &:checked  { background-color: $titlebutton_normal_active; }
+      &:backdrop { background: $titlebutton_backdrop; }
+      &:backdrop:hover { background: $titlebutton_backdrop_hover; }
+    }
+  }
+
+  &:not(:first-child) > .titlebar {
+    border-bottom: transparent;
+    box-shadow: none;
+  }
+}
+
+.geary-main-window separator.sidebar {
+  background-color: $borders_color;
 }
 
 // ************