Downgrade css to prevent older browsers displaying faulty views

public/index.html

@@ -5,7 +5,9 @@
   <meta name="viewport" content="width=device-width, initial-scale=1, viewport-fit=cover">
   <meta name="theme-color" content="#315d3a">
   <title>Wegwichtel</title>
-  <link rel="stylesheet" href="css/bootstrap.css?v=0.12.11">
+  <link rel="stylesheet" href="css/bootstrap.css?v=0.12.12">
+  <link rel="stylesheet" href="vendor/jquery-ui/jquery-ui-1.14.2.min.css?v=0.12.12">
+  <link rel="stylesheet" href="css/app.css?v=0.12.12">
 </head>
 <body>
   <div id="bootstrap-screen" aria-live="polite" aria-busy="true">
@@ -41,7 +43,9 @@
 
         <section>
           <h2>Routen in deiner Nähe</h2>
-          <ul id="nearby-route-list" class="route-list" aria-live="polite"></ul>
+          <ul id="nearby-route-list" class="route-list" aria-live="polite">
+            <li><p>Routen werden geladen …</p></li>
+          </ul>
         </section>
 
         <section>
@@ -58,14 +62,16 @@
             <button id="clear-route-search" type="button">Suche leeren</button>
           </div>
 
-          <p id="all-routes-summary" aria-live="polite"></p>
-          <ul id="all-route-list" class="route-list" aria-live="polite"></ul>
+          <p id="all-routes-summary" aria-live="polite">Routen werden geladen …</p>
+          <ul id="all-route-list" class="route-list" aria-live="polite">
+            <li><p>Routen werden geladen …</p></li>
+          </ul>
         </section>
       </div>
     </section>
 
     <section id="route-page" class="app-page" hidden>
-      <header>
+      <header class="has-back-button">
         <button class="back-button" type="button" data-page-target="#routes-page" aria-label="Zurück zur Routenauswahl" title="Zurück zur Routenauswahl">
           <img src="images/icons/back.svg" alt="">
         </button>
@@ -101,7 +107,7 @@
     </section>
 
     <section id="poi-page" class="app-page" hidden>
-      <header>
+      <header class="has-back-button">
         <button class="back-button" type="button" data-page-target="#route-page" aria-label="Zurück zur Route" title="Zurück zur Route">
           <img src="images/icons/back.svg" alt="">
         </button>
@@ -145,6 +151,6 @@
     </footer>
   </main>
 
-  <script src="js/bootstrap-loader.js?v=0.12.11"></script>
+  <script src="js/bootstrap-loader.js?v=0.12.12"></script>
 </body>
 </html>