sorting comments after event title and created at in index

app/controllers/admin/comments_controller.rb

@@ -3,7 +3,7 @@ module Admin
     load_and_authorize_resource
 
     def index
-      @comments = Comment.accessible_by(current_ability).order(created_at: :desc).group_by { |comment| comment.commentable.conference }.map {|conference, comments| [conference, comments.group_by {|comment| comment.commentable}]}.to_h
+      @comments = Comment.accessible_by(current_ability).joins('INNER JOIN events ON commentable_id = events.id').order('events.title', 'comments.created_at DESC').group_by{ |comment| comment.commentable.conference }.map {|conference, comments| [conference, comments.group_by{|comment| comment.commentable}]}.to_h
     end
   end
 end

app/views/admin/comments/_all_comments.html.haml

@@ -1,9 +1,9 @@
 .panel.well
   %ul
   - @comments.each do |conference, events|
-    %li= conference.title
+    %i.li= conference.title
     - events.each do |event, comments|
-      %li= event.title
+      %b.li= event.title
       - comments.each do |comment|
         %li= comment.body
         %li= comment.user.name