fix nav collapse styling and recent-posts thumbnail float clear

assets/css/app.scss

@@ -310,6 +310,9 @@ main#fp-main > div.fp-grid {
       color: $text-muted;
       font-size: smaller;
     }
+    .rpwwt-post-excerpt {
+      clear: both;
+    }
   }
   .tsml-widget-upcoming.widget_tsml_widget_upcoming.widget p {
     text-align: right;