doit

templates/index.html

@@ -3,7 +3,7 @@
     <head>
         <title>Vokabeltrainer - B. Runden</title>
         <link rel="icon" type="image/png" href="./images/favicon.png"/>
-        <link rel="stylesheet" href="url_for('static', filename='style.css')">
+        <link rel="stylesheet" href="{{ url_for('static', filename='style.css') }}">
     </head>
     <body>
         <p>