[gnome-calendar] css: simpler edit-dialog headerbar button

[Lapo Calamandrei <lapo src gnome org>]

commit 7f8cb1a25dcac82260e1277be77cfc2d94499a0e
Author: Lapo Calamandrei <calamandrei gmail com>
Date:   Fri Jul 8 01:56:06 2016 +0200

    css: simpler edit-dialog headerbar button
    
    make it full height and visually cleaner.

 data/theme/gtk-styles.css |   27 +++++++++++++--------------
 1 files changed, 13 insertions(+), 14 deletions(-)
---
diff --git a/data/theme/gtk-styles.css b/data/theme/gtk-styles.css
index 5e583fc..9d32b06 100644
--- a/data/theme/gtk-styles.css
+++ b/data/theme/gtk-styles.css
@@ -279,22 +279,21 @@ event-widget.color-light:backdrop {
 }
 
 /* Edit dialog's header button */
-button.sources-button {
-    border: none;
-    background: transparent;
-    box-shadow: none;
-    padding-bottom: 0;
-    padding-top: 0;
+.sources-button {
+    margin-top: 0;
+    margin-bottom: 0;
+    border-radius: 0;
+    border-top-style: none;
+    border-bottom-style: none;
+    -gtk-icon-effect: none;
 }
 
-button.sources-button:hover {
-    background: @theme_bg_color;
-    border-bottom: solid 2px @theme_selected_bg_color;
-    box-shadow: none;
+.sources-button:hover:not(:backdrop) {
+    background-image: none;
+    text-shadow: none;
+    icon-shadow: 0 1px alpha(black, 0.1);
 }
 
-button.sources-button:checked {
-    background: @theme_bg_color;
-    border-bottom: solid 2px @theme_selected_bg_color;
-    box-shadow: none;
+.sources-button:not(:backdrop) {
+    icon-shadow: 0 1px alpha(black, 0.1);
 }