[gnome-games] style: Add style for collection thumbnails

[Alexander Mikhaylenko <alexm src gnome org>]

commit 02c05e2042225437a2f06e7e2d146978277b3c18
Author: Neville <nevilleantony98 gmail com>
Date:   Thu Jun 18 22:10:26 2020 +0530

    style: Add style for collection thumbnails

 data/gtk-style.css | 20 ++++++++++++++++++++
 1 file changed, 20 insertions(+)
---
diff --git a/data/gtk-style.css b/data/gtk-style.css
index 32608467..7d6bc0fe 100644
--- a/data/gtk-style.css
+++ b/data/gtk-style.css
@@ -35,6 +35,26 @@
        border-right: none;
 }
 
+gamescollectionsmainpage grid {
+       background: mix(@theme_base_color, @theme_bg_color, 0.5);
+       min-width: 116px;
+       min-height: 116px;
+       border-radius: 6px;
+       padding: 6px;
+}
+
+gamescollectionsmainpage.large grid {
+       min-width: 244px;
+       min-height: 244px;
+}
+
+gamescollectionsmainpage grid widget {
+       background: alpha(black, 0.2);
+       border-radius: 6px;
+       border: 1px solid @borders;
+}
+
+
 gamesgamethumbnail {
        background-color: mix(@theme_base_color, @theme_bg_color, 0.5);
        border-radius: 6px;