Use small spacing for grouped fundamentals content cards

styleguide.css

@@ -1718,6 +1718,12 @@ section + section {
     var(--card-segment-padding-horizontal);
 }
 
+.sg-card-list-page-detail-group {
+  display: flex;
+  flex-direction: column;
+  gap: var(--spacing-small);
+}
+
 .sg-card-list-page-mobile-detail {
   display: none;
   flex-direction: column;