Better Aero implementation

Author: K4sum1

browser/themes/shared/browser-shared.css

@@ -158,31 +158,34 @@
 
   /* Toolbar / content area border */
   border-bottom: 1px solid var(--chrome-content-separator-color);
+  @media not (-moz-platform: windows-win7) {
+    @media not (-moz-platform: windows-win8) {
+      background-color: var(--toolbox-non-lwt-bgcolor);
+      color: var(--toolbox-non-lwt-textcolor);
+
+      will-change: background-color;
+      transition: background-color var(--inactive-window-transition);
+    
+      &:-moz-window-inactive {
+        background-color: var(--toolbox-non-lwt-bgcolor-inactive);
+        color: var(--toolbox-non-lwt-textcolor-inactive);
+      }
 
-  background-color: var(--toolbox-non-lwt-bgcolor);
-  color: var(--toolbox-non-lwt-textcolor);
-
-  will-change: background-color;
-  transition: background-color var(--inactive-window-transition);
-
-  &:-moz-window-inactive {
-    background-color: var(--toolbox-non-lwt-bgcolor-inactive);
-    color: var(--toolbox-non-lwt-textcolor-inactive);
-  }
-
-  :root[customizing] & {
-    border-bottom-style: none;
-  }
-
-  &:-moz-lwtheme {
-    background-image: var(--lwt-additional-images);
-    background-repeat: var(--lwt-background-tiling);
-    background-position: var(--lwt-background-alignment);
-    background-color: var(--lwt-accent-color);
-    color: inherit;
-
-    &:-moz-window-inactive {
-      background-color: var(--lwt-accent-color-inactive, var(--lwt-accent-color));
+      :root[customizing] & {
+        border-bottom-style: none;
+      }
+    
+      &:-moz-lwtheme {
+        background-image: var(--lwt-additional-images);
+        background-repeat: var(--lwt-background-tiling);
+        background-position: var(--lwt-background-alignment);
+        background-color: var(--lwt-accent-color);
+        color: inherit;
+    
+        &:-moz-window-inactive {
+          background-color: var(--lwt-accent-color-inactive, var(--lwt-accent-color));
+        }
+      }
     }
   }
 

browser/themes/windows/browser-aero.css

@@ -249,12 +249,6 @@
       -moz-default-appearance: -moz-win-borderless-glass;
     }
 
-    /* Allows seeing the caption bar on Windows pre-10 */
-    #navigator-toolbox,
-    #navigator-toolbox-background {
-      background-color: transparent;
-    }
-
     :root[sizemode="maximized"] .titlebar-buttonbox {
       margin-inline-end: 3px;
     }