[gnome-shell-sass] screenshot-ui: Add close button

[Florian Müllner <fmuellner src gnome org>]

commit bb876cbeb191c5f3f8a8c382f16759a4ba1629b8
Author: Ivan Molodetskikh <yalterz gmail com>
Date:   Sun Jan 23 13:53:35 2022 +0300

    screenshot-ui: Add close button
    
    Part-of: <https://gitlab.gnome.org/GNOME/gnome-shell/-/merge_requests/1954>

 widgets/_screenshot.scss | 16 ++++++++++++++++
 1 file changed, 16 insertions(+)
---
diff --git a/widgets/_screenshot.scss b/widgets/_screenshot.scss
index d28aacb..aa1a11a 100644
--- a/widgets/_screenshot.scss
+++ b/widgets/_screenshot.scss
@@ -7,3 +7,19 @@
   margin-bottom: $base_margin * 8;
   spacing: $base_padding * 2;
 }
+
+.screenshot-ui-close-button {
+  background-color: $osd_bg_color;
+  border-radius: 99px;
+  width: 64px;
+  height: 64px;
+  margin: 64px;
+
+  &:hover, &:focus { background-color: $hover_bg_color; }
+  &:active { background-color: $active_bg_color; }
+  &:checked { background-color: darken($osd_bg_color, 5%); }
+
+  StIcon {
+    icon-size: $base_icon_size * 2;
+  }
+}