[gnome-tweak-tool] shell.css: Make tweak-group and tweak have a transparent background

[Rui Matos <rtcm src gnome org>]

commit 05e7d5006ff781c934ff065d9a338280fadc5e2d
Author: Rui Matos <tiagomatos gmail com>
Date:   Fri Mar 6 17:19:07 2015 +0100

    shell.css: Make tweak-group and tweak have a transparent background
    
    This just lets the parent's widget background get through which was
    the intent here in the first place but this way we should be shielded
    from gtk+ theme changes.
    
    https://bugzilla.gnome.org/show_bug.cgi?id=745706

 data/shell.css |    6 +++---
 1 files changed, 3 insertions(+), 3 deletions(-)
---
diff --git a/data/shell.css b/data/shell.css
index c4ae112..2662298 100644
--- a/data/shell.css
+++ b/data/shell.css
@@ -8,15 +8,15 @@
 
 /* the container and tweaks in a group */
 .tweak-group {
-    background-color: @theme_bg_color;
+    background-color: rgba(0, 0, 0, 0);
 }
 
 .tweak {
     padding-top: 3px;
-    background-color: @theme_bg_color;
+    background-color: rgba(0, 0, 0, 0);
 }
 .tweak:hover {
-    background-color: @theme_bg_color;
+    background-color: rgba(0, 0, 0, 0);
 }
 .tweak.title {
     padding-top: 10px;