Add 404 page.

app/controllers/application_controller.rb

@@ -1,6 +1,8 @@
 class ApplicationController < ActionController::Base
   protect_from_forgery
 
+  rescue_from ActiveRecord::RecordNotFound, :with => :render_404
+
   def after_sign_in_path_for(resource_or_scope)
     admin_dashboard_path
   end
@@ -9,4 +11,8 @@ class ApplicationController < ActionController::Base
     new_admin_user_session_path
   end
 
+  def render_404
+    render 'errors/not_found', :status => 404
+  end
+
 end

app/controllers/pages_controller.rb

@@ -1,6 +1,6 @@
 class PagesController < ApplicationController
   def show
-    @page = Page.find_by_name(params[:name])
+    @page = Page.find_by_name!(params[:name])
     @page_title = @page.title
   end
 end

app/views/errors/not_found.html.erb

@@ -0,0 +1 @@
+<h1 class="sg-1">404</h1>