fixed links on front page

templates/macros.html

 {% macro preview(lecture) %}
 
 <li class="list-group-item">
-	<div class="row">
 	<a class="hidden-xs" href="/play?lectureid={{ lecture['id'] }}" title="{{ lecture['coursetitle'] }}">
+		<div class="row">
 			<img class="col-xs-4" src="https://videoag.fsmpi.rwth-aachen.de/{{ lecture['titlefile'] }}" alt="Vorschaubild">
 			<div class="col-xs-4">
 				<span style="color: #000;"><strong>{{ lecture['short'] }}</strong></span><br>
@@ -15,6 +15,7 @@
 				<div style="color: #000;">{{ lecture['title']  }}</div>
 				<p style="font-style: italic; color: #777;">{{ lecture['comment'] }}</p>
 			</div>
+		</div>
 	</a>
 	<a class="visible-xs" href="/play?lectureid={{ lecture['id'] }}" title="{{ lecture['coursetitle'] }}">
 		<div class="row">
@@ -44,7 +45,6 @@
 			</div>
 		</div>
 	</a>
-	</div>
 </li>
 
 {% endmacro %}