Hide wiki title when smartphone view

lib/views/layout/layout.html

@@ -30,7 +30,7 @@
   <div class="navbar-header">
     <a class="navbar-brand" href="/">
       <img alt="Crowi" src="/logo/32x32.png" width="16">
-      {% block title %}{{ config.crowi['app:title']|default('Crowi') }}{% endblock %}
+      <span class="hidden-xs">{% block title %}{{ config.crowi['app:title']|default('Crowi') }}{% endblock %}</span>
     </a>
   {% if searchConfigured() %}
   <div class="navbar-form navbar-left search-top" role="search" id="search-top">