Warning in offline settings when more than one puzzle

app/views/contests/settings_offline_edit.html.slim

@@ -1,5 +1,12 @@
 = render "settings_nav"
 
+- if @contest.puzzles.length > 1
+  .row
+    .col
+      .alert.alert-warning
+        = t("contests.form.offline_single_puzzle_warning")
+
+- if @contest.puzzles.length <= 1
   = form_with model: @contest, url: "/contests/#{@contest.id}/settings/offline" do |form|
     .row.mt-2.mb-3
       .col

config/locales/en.yml

@@ -177,6 +177,7 @@ en:
       categories: Participant categories
       general: General parameters
       offline: Offline participation
+      offline_single_puzzle_warning: This is not available for contests with more than one puzzle
     index:
       title: Welcome %{username}!
       manage_contests: Manage my contests

config/locales/fr.yml

@@ -148,6 +148,7 @@ fr:
       categories: Catégories de participant.e.s
       general: Paramètres généraux
       offline: Participation hors-ligne
+      offline_single_puzzle_warning: Ce n'est pas activable pour les concours avec plusieurs puzzles
     index:
       title: Bienvenue %{username} !
       manage_contests: Mes concours de puzzle