diff --git a/lib/screens/detail_widget.dart b/lib/screens/detail_widget.dart
index 564b794..8c19439 100644
--- a/lib/screens/detail_widget.dart
+++ b/lib/screens/detail_widget.dart
@@ -172,7 +172,11 @@ class Frame28 extends StatelessWidget {
               start_time:
                   extractTime24h(events[index]['time'][0]['start_date']),
                   
-              color: extractColor(events[index]['main_category_id']),
+              color: events[index]['main_category_id'] != null 
+                      ? extractColor(events[index]['main_category_id']) 
+                      : color,
+              //extractColor(events[index]['main_category_id']),
+               // oder ein beliebiger Standardwert
               screen_size: screen_size,
             );
           },
diff --git a/lib/screens/home.dart b/lib/screens/home.dart
index 313e2f6..931d8a9 100644
--- a/lib/screens/home.dart
+++ b/lib/screens/home.dart
@@ -103,8 +103,11 @@ class _HomePage  extends State<HomePage> {
     //single_categories.updateCategoryAmount('Ingolstadt');
     /*24 is for notification bar on Android*/
     //final double itemHeight = (size.height - kToolbarHeight - 270) / 4; 290 for iOs 230 android
-    final double itemHeight = (size.height - 230-90) / 4;
+    final double itemHeight = (size.height - 240-90) / 4;
     final double itemWidth = (size.width-40)/ 2;
+        // Verfügbarer Bereich auf dem Bildschirm
+    final screenWidth = MediaQuery.of(context).size.width;
+    final screenHeight = MediaQuery.of(context).size.height;
       MediaQueryData queryData;
   queryData = MediaQuery.of(context);