Improve visual

ui/src/routes/index.svelte

@@ -49,3 +49,5 @@
         <SurveyList bind:direct={direct} />
     </div>
 </div>
+
+<div class="mb-5"></div>

ui/src/routes/surveys/[sid]/index.svelte

@@ -62,5 +62,15 @@
         </div>
     {:then questions}
         <SurveyQuestions {survey} {questions} />
+    {:catch error}
+        <div class="row mt-5">
+            <div class="d-none d-sm-block col-sm">
+                <hr>
+            </div>
+            <h3 class="col-sm-auto text-center text-muted mb-3"><label for="askquestion">Ce questionnaire n'est pas accessible</label></h3>
+            <div class="d-none d-sm-block col-sm">
+                <hr>
+            </div>
+        </div>
     {/await}
 {/await}

ui/src/routes/surveys/index.svelte

@@ -6,3 +6,5 @@
 <div class="card bg-light">
     <SurveyList />
 </div>
+
+<div class="mb-5"></div>