diff --git a/it0_app/lib/features/chat/presentation/pages/chat_page.dart b/it0_app/lib/features/chat/presentation/pages/chat_page.dart
index 3c6ff7e..b4f82de 100644
--- a/it0_app/lib/features/chat/presentation/pages/chat_page.dart
+++ b/it0_app/lib/features/chat/presentation/pages/chat_page.dart
@@ -51,6 +51,15 @@ class _ChatPageState extends ConsumerState<ChatPage> {
     );
   }
 
+  /// Whether to show a virtual "working" node at the bottom of the timeline.
+  /// True when the agent is streaming but no assistant message has appeared yet.
+  bool _needsWorkingNode(ChatState chatState) {
+    if (!chatState.isStreaming) return false;
+    if (chatState.messages.isEmpty) return false;
+    // Show working node if the last message is still the user's prompt
+    return chatState.messages.last.role == MessageRole.user;
+  }
+
   // -- Timeline node builder ------------------------------------------------
 
   Widget _buildTimelineNode(
@@ -242,14 +251,31 @@ class _ChatPageState extends ConsumerState<ChatPage> {
                 : ListView.builder(
                     controller: _scrollController,
                     padding: const EdgeInsets.fromLTRB(12, 8, 12, 8),
-                    itemCount: chatState.messages.length,
+                    // Extra item for the "working" placeholder when streaming
+                    // and the last message is still a user message (no agent
+                    // response has arrived yet).
+                    itemCount: chatState.messages.length +
+                        (_needsWorkingNode(chatState) ? 1 : 0),
                     itemBuilder: (context, index) {
+                      // Render the virtual "working" node at the end
+                      if (index == chatState.messages.length &&
+                          _needsWorkingNode(chatState)) {
+                        return TimelineEventNode(
+                          status: NodeStatus.active,
+                          label: '处理中...',
+                          isFirst: false,
+                          isLast: false,
+                        );
+                      }
+                      final isRealLast =
+                          index == chatState.messages.length - 1;
                       return _buildTimelineNode(
                         chatState.messages[index],
                         chatState,
                         isFirst: index == 0,
-                        isLast: index == chatState.messages.length - 1 &&
-                            !chatState.isStreaming,
+                        isLast: isRealLast &&
+                            !chatState.isStreaming &&
+                            !_needsWorkingNode(chatState),
                       );
                     },
                   ),
diff --git a/it0_app/lib/features/chat/presentation/providers/chat_providers.dart b/it0_app/lib/features/chat/presentation/providers/chat_providers.dart
index d3b8a89..7664eae 100644
--- a/it0_app/lib/features/chat/presentation/providers/chat_providers.dart
+++ b/it0_app/lib/features/chat/presentation/providers/chat_providers.dart
@@ -194,6 +194,22 @@ class ChatNotifier extends StateNotifier<ChatState> {
         );
 
       case ToolResultEvent(:final toolName, :final output, :final isError):
+        // First, update the matching ToolUse message's status so its spinner
+        // transitions to a completed/error icon in the timeline.
+        final updatedMessages = [...state.messages];
+        for (int i = updatedMessages.length - 1; i >= 0; i--) {
+          final m = updatedMessages[i];
+          if (m.type == MessageType.toolUse &&
+              m.toolExecution?.status == ToolStatus.executing) {
+            updatedMessages[i] = m.copyWith(
+              toolExecution: m.toolExecution!.copyWith(
+                status: isError ? ToolStatus.error : ToolStatus.completed,
+              ),
+            );
+            break;
+          }
+        }
+
         final msg = ChatMessage(
           id: DateTime.now().microsecondsSinceEpoch.toString(),
           role: MessageRole.assistant,
@@ -208,7 +224,7 @@ class ChatNotifier extends StateNotifier<ChatState> {
             status: isError ? ToolStatus.error : ToolStatus.completed,
           ),
         );
-        state = state.copyWith(messages: [...state.messages, msg]);
+        state = state.copyWith(messages: [...updatedMessages, msg]);
 
       case ApprovalRequiredEvent(:final taskId, :final command, :final riskLevel):
         final msg = ChatMessage(
diff --git a/it0_app/lib/features/chat/presentation/widgets/timeline_event_node.dart b/it0_app/lib/features/chat/presentation/widgets/timeline_event_node.dart
index be1f179..c376ab9 100644
--- a/it0_app/lib/features/chat/presentation/widgets/timeline_event_node.dart
+++ b/it0_app/lib/features/chat/presentation/widgets/timeline_event_node.dart
@@ -1,4 +1,3 @@
-import 'dart:math' as math;
 import 'package:flutter/material.dart';
 import '../../../../core/theme/app_colors.dart';
 
@@ -132,7 +131,7 @@ class _StaticDot extends StatelessWidget {
   }
 }
 
-/// Animated spinning asterisk for active nodes.
+/// Animated pulsing asterisk for active nodes (scale up/down like a star).
 class _SpinnerDot extends StatefulWidget {
   final Color color;
   const _SpinnerDot({required this.color});
@@ -150,8 +149,8 @@ class _SpinnerDotState extends State<_SpinnerDot>
     super.initState();
     _controller = AnimationController(
       vsync: this,
-      duration: const Duration(milliseconds: 1000),
-    )..repeat();
+      duration: const Duration(milliseconds: 800),
+    )..repeat(reverse: true);
   }
 
   @override
@@ -165,12 +164,14 @@ class _SpinnerDotState extends State<_SpinnerDot>
     return AnimatedBuilder(
       animation: _controller,
       builder: (_, __) {
-        return Transform.rotate(
-          angle: _controller.value * 2 * math.pi,
+        // Pulse between 0.6x and 1.2x scale
+        final scale = 0.6 + _controller.value * 0.6;
+        return Transform.scale(
+          scale: scale,
           child: Text(
             '*',
             style: TextStyle(
-              color: widget.color,
+              color: widget.color.withValues(alpha: 0.6 + _controller.value * 0.4),
               fontSize: 18,
               fontWeight: FontWeight.bold,
               height: 1,