Fixes #12625: Only remove first list group item's top and last list group item's bottom borders when the list group is first or last

less/panels.less

@@ -58,25 +58,23 @@
 .panel {
   > .list-group {
     margin-bottom: 0;
+
     .list-group-item {
       border-width: 1px 0;
       border-radius: 0;
-      &:first-child {
-        border-top: 0;
-      }
-      &:last-child {
-        border-bottom: 0;
-      }
     }
+
     // Add border top radius for first one
     &:first-child {
       .list-group-item:first-child {
+        border-top: 0;
         .border-top-radius((@panel-border-radius - 1));
       }
     }
     // Add border bottom radius for last one
     &:last-child {
       .list-group-item:last-child {
+        border-bottom: 0;
         .border-bottom-radius((@panel-border-radius - 1));
       }
     }
@@ -104,7 +102,7 @@
   > .table:first-child,
   > .table-responsive:first-child > .table:first-child {
     .border-top-radius((@panel-border-radius - 1));
-	
+
     > thead:first-child,
     > tbody:first-child {
       > tr:first-child {
@@ -123,7 +121,7 @@
   > .table:last-child,
   > .table-responsive:last-child > .table:last-child {
     .border-bottom-radius((@panel-border-radius - 1));
-    
+
     > tbody:last-child,
     > tfoot:last-child {
       > tr:last-child {