[gnome-shell] theme: Update window preview style

[Florian Müllner <fmuellner src gnome org>]

commit 49c95cff6c9c35e10bc11aab86d75bb0f0d295f6
Author: Feichtmeier <frederik feichtmeier gmail com>
Date:   Fri Mar 15 14:41:55 2019 +0100

    theme: Update window preview style
    
     - simplify the close button to use blue, lighter blue and darker blue
       solid disks for normal, hover and active states
    
     - use a milky, transparent white border for the hover effect of the border
    
    https://gitlab.gnome.org/GNOME/gnome-shell/merge_requests/461

 data/theme/gnome-shell-sass/_common.scss | 29 ++++++++++++++---------------
 1 file changed, 14 insertions(+), 15 deletions(-)
---
diff --git a/data/theme/gnome-shell-sass/_common.scss b/data/theme/gnome-shell-sass/_common.scss
index a6357baad..67e5954cb 100644
--- a/data/theme/gnome-shell-sass/_common.scss
+++ b/data/theme/gnome-shell-sass/_common.scss
@@ -1150,25 +1150,23 @@ StScrollBar {
 //close buttons
 
 .window-close {
-  background-color: white;
+  background-color: $selected_bg_color;
+  color: white;
   border-radius: 24px;
-  border: 4px solid $selected_bg_color;
-  box-shadow: inset 0 -4px 0 0 transparentize($selected_bg_color, 0.5);
-  color: $selected_bg_color;
+  border: 2px solid $selected_bg_color;
   height: 24px;
   width: 24px;
-  -shell-close-overlap: 14px;
+  -shell-close-overlap: 11px;
+  box-shadow: -1px 1px 5px 0px transparentize(black, 0.5);
 
   &:hover {
-    background-color: $selected_bg_color;
-    border-color: white;
-    color: white;
+    background-color: lighten($selected_bg_color, 5%);
+    border-color: lighten($selected_bg_color, 5%);
   }
 
   &:active {
-    background-color: mix(white, $selected_bg_color, 75%);
-    border-color: $selected_bg_color;
-    color: $selected_bg_color;
+    background-color: darken($selected_bg_color, 5%);
+    border-color: darken($selected_bg_color, 5%);
   }
 }
 
@@ -1233,13 +1231,14 @@ StScrollBar {
   }
 
   .window-clone-border {
-    border: 4px solid $selected_bg_color;
-    border-radius: 4px;
+    $_bg: transparentize(white, 0.65);
+    border: 5px solid $_bg;
+    border-radius: 6px;
     // For window decorations with round corners we can't match
     // the exact shape when the window is scaled. So apply a shadow
     // to fix that case
-    box-shadow: inset 0px 0px 0px 1px $selected_bg_color;
-  }
+    box-shadow: inset 0 0 0 1px $_bg;
+}
   .window-caption {
     spacing: 25px;
     color: $selected_fg_color;