Replace Container with AnimatedContainer in CommunityStructureCanvas to enhance visual feedback during state changes. Adjust alpha value for improved visibility based on candidate data presence.

lib/pages/space_management_v2/main_module/widgets/community_structure_canvas.dart

@@ -445,13 +445,14 @@ class _CommunityStructureCanvasState extends State<CommunityStructureCanvas>
             return const SizedBox.shrink();
           }
 
-          return Container(
+          return AnimatedContainer(
+            duration: const Duration(milliseconds: 150),
             width: 40,
             alignment: Alignment.center,
             height: _cardHeight,
             decoration: BoxDecoration(
               color: context.theme.colorScheme.primary.withValues(
-                alpha: candidateData.isNotEmpty ? 0.7 : 0.3,
+                alpha: candidateData.isNotEmpty ? 0.9 : 0.3,
               ),
               borderRadius: BorderRadius.circular(8),
             ),