diff --git a/.claude/settings.local.json b/.claude/settings.local.json
index e00609d..f5968bb 100644
--- a/.claude/settings.local.json
+++ b/.claude/settings.local.json
@@ -15,7 +15,8 @@
       "Bash(ssh:*)",
       "Bash(ping:*)",
       "Bash(curl:*)",
-      "Bash(echo \"No health endpoint\" curl -s https://iconsulting.szaiai.com/api/v1/users/profile -H \"x-user-id: test\")"
+      "Bash(echo \"No health endpoint\" curl -s https://iconsulting.szaiai.com/api/v1/users/profile -H \"x-user-id: test\")",
+      "Bash(scp:*)"
     ]
   }
 }
diff --git a/packages/services/conversation-service/src/conversation/conversation.controller.ts b/packages/services/conversation-service/src/conversation/conversation.controller.ts
index de447df..010d52d 100644
--- a/packages/services/conversation-service/src/conversation/conversation.controller.ts
+++ b/packages/services/conversation-service/src/conversation/conversation.controller.ts
@@ -2,6 +2,7 @@ import {
   Controller,
   Get,
   Post,
+  Delete,
   Param,
   Body,
   Headers,
@@ -144,4 +145,21 @@ export class ConversationController {
       message: 'Conversation ended',
     };
   }
+
+  /**
+   * Delete a conversation
+   */
+  @Delete(':id')
+  @HttpCode(HttpStatus.OK)
+  async deleteConversation(
+    @Headers('x-user-id') userId: string,
+    @Param('id') conversationId: string,
+  ) {
+    await this.conversationService.deleteConversation(conversationId, userId);
+
+    return {
+      success: true,
+      message: 'Conversation deleted',
+    };
+  }
 }
diff --git a/packages/services/conversation-service/src/conversation/conversation.service.ts b/packages/services/conversation-service/src/conversation/conversation.service.ts
index 33c894e..eba93a7 100644
--- a/packages/services/conversation-service/src/conversation/conversation.service.ts
+++ b/packages/services/conversation-service/src/conversation/conversation.service.ts
@@ -187,6 +187,20 @@ export class ConversationService {
     });
   }
 
+  /**
+   * Delete a conversation and its messages
+   */
+  async deleteConversation(conversationId: string, userId: string): Promise<void> {
+    // Verify user owns the conversation
+    const conversation = await this.getConversation(conversationId, userId);
+
+    // Delete messages first (due to foreign key constraint)
+    await this.messageRepo.delete({ conversationId: conversation.id });
+
+    // Delete conversation
+    await this.conversationRepo.delete(conversation.id);
+  }
+
   /**
    * Generate a title from the first message
    */
diff --git a/packages/web-client/src/features/chat/presentation/components/ChatSidebar.tsx b/packages/web-client/src/features/chat/presentation/components/ChatSidebar.tsx
index 22ee0bc..3041ab4 100644
--- a/packages/web-client/src/features/chat/presentation/components/ChatSidebar.tsx
+++ b/packages/web-client/src/features/chat/presentation/components/ChatSidebar.tsx
@@ -1,13 +1,15 @@
+import { useState } from 'react';
 import { useNavigate } from 'react-router-dom';
-import { Plus, MessageSquare, Trash2 } from 'lucide-react';
+import { Plus, MessageSquare, Trash2, ChevronLeft } from 'lucide-react';
 import { clsx } from 'clsx';
 import { useChatStore } from '../stores/chatStore';
 import { useChat } from '../hooks/useChat';
 
 export function ChatSidebar() {
   const navigate = useNavigate();
-  const { conversations, currentConversationId } = useChatStore();
+  const { conversations, currentConversationId, userId, deleteConversation, toggleSidebar } = useChatStore();
   const { createConversation } = useChat();
+  const [deletingId, setDeletingId] = useState<string | null>(null);
 
   const handleNewChat = async () => {
     const conversationId = await createConversation();
@@ -20,17 +22,38 @@ export function ChatSidebar() {
     navigate(`/chat/${id}`);
   };
 
+  const handleDeleteConversation = async (id: string) => {
+    if (!userId || deletingId) return;
+
+    setDeletingId(id);
+    const success = await deleteConversation(userId, id);
+    setDeletingId(null);
+
+    if (success && currentConversationId === id) {
+      navigate('/chat');
+    }
+  };
+
   return (
     <div className="flex flex-col h-full">
       {/* Header */}
       <div className="p-4 border-b border-secondary-200">
-        <button
-          onClick={handleNewChat}
-          className="w-full flex items-center justify-center gap-2 btn-primary py-2.5"
-        >
-          <Plus className="w-4 h-4" />
-          <span>新建对话</span>
-        </button>
+        <div className="flex items-center gap-2">
+          <button
+            onClick={handleNewChat}
+            className="flex-1 flex items-center justify-center gap-2 btn-primary py-2.5"
+          >
+            <Plus className="w-4 h-4" />
+            <span>新建对话</span>
+          </button>
+          <button
+            onClick={toggleSidebar}
+            className="hidden md:flex p-2.5 hover:bg-secondary-100 rounded-lg transition-colors"
+            title="收起侧边栏"
+          >
+            <ChevronLeft className="w-5 h-5 text-secondary-500" />
+          </button>
+        </div>
       </div>
 
       {/* Conversation list */}
@@ -49,7 +72,9 @@ export function ChatSidebar() {
                 title={conv.title || '新对话'}
                 isActive={conv.id === currentConversationId}
                 updatedAt={conv.updatedAt}
+                isDeleting={deletingId === conv.id}
                 onClick={() => handleSelectConversation(conv.id)}
+                onDelete={() => handleDeleteConversation(conv.id)}
               />
             ))}
           </div>
@@ -71,14 +96,18 @@ interface ConversationItemProps {
   title: string;
   isActive: boolean;
   updatedAt: string;
+  isDeleting: boolean;
   onClick: () => void;
+  onDelete: () => void;
 }
 
 function ConversationItem({
   title,
   isActive,
   updatedAt,
+  isDeleting,
   onClick,
+  onDelete,
 }: ConversationItemProps) {
   const formatTime = (dateStr: string) => {
     const date = new Date(dateStr);
@@ -106,11 +135,13 @@ function ConversationItem({
   return (
     <button
       onClick={onClick}
+      disabled={isDeleting}
       className={clsx(
         'w-full flex items-center gap-3 px-3 py-2.5 rounded-lg text-left transition-colors group',
         isActive
           ? 'bg-primary-50 text-primary-700'
           : 'hover:bg-secondary-50 text-secondary-700',
+        isDeleting && 'opacity-50 cursor-not-allowed',
       )}
     >
       <MessageSquare
@@ -123,15 +154,20 @@ function ConversationItem({
         <p className="text-sm font-medium truncate">{title}</p>
         <p className="text-xs text-secondary-400">{formatTime(updatedAt)}</p>
       </div>
-      <button
-        onClick={(e) => {
-          e.stopPropagation();
-          // TODO: Implement delete
-        }}
-        className="opacity-0 group-hover:opacity-100 p-1 hover:bg-secondary-200 rounded transition-all"
-      >
-        <Trash2 className="w-3.5 h-3.5 text-secondary-400" />
-      </button>
+      {isDeleting ? (
+        <div className="w-4 h-4 border-2 border-secondary-400 border-t-transparent rounded-full animate-spin" />
+      ) : (
+        <button
+          onClick={(e) => {
+            e.stopPropagation();
+            onDelete();
+          }}
+          className="opacity-0 group-hover:opacity-100 p-1 hover:bg-red-100 hover:text-red-600 rounded transition-all"
+          title="删除对话"
+        >
+          <Trash2 className="w-3.5 h-3.5" />
+        </button>
+      )}
     </button>
   );
 }
diff --git a/packages/web-client/src/features/chat/presentation/pages/ChatPage.tsx b/packages/web-client/src/features/chat/presentation/pages/ChatPage.tsx
index 2c17b06..db9e1ed 100644
--- a/packages/web-client/src/features/chat/presentation/pages/ChatPage.tsx
+++ b/packages/web-client/src/features/chat/presentation/pages/ChatPage.tsx
@@ -1,5 +1,7 @@
 import { useEffect } from 'react';
 import { useParams } from 'react-router-dom';
+import { Menu, X } from 'lucide-react';
+import { clsx } from 'clsx';
 import { ChatWindow } from '../components/ChatWindow';
 import { ChatSidebar } from '../components/ChatSidebar';
 import { useChatStore } from '../stores/chatStore';
@@ -8,7 +10,7 @@ import { useAnonymousAuth } from '@/shared/hooks/useAnonymousAuth';
 export default function ChatPage() {
   const { conversationId } = useParams();
   const { userId, isLoading: authLoading } = useAnonymousAuth();
-  const { setCurrentConversation, loadConversations } = useChatStore();
+  const { setCurrentConversation, loadConversations, sidebarOpen, toggleSidebar, setSidebarOpen } = useChatStore();
 
   useEffect(() => {
     if (userId) {
@@ -22,6 +24,13 @@ export default function ChatPage() {
     }
   }, [conversationId, setCurrentConversation]);
 
+  // Close sidebar on mobile when selecting a conversation
+  useEffect(() => {
+    if (conversationId && window.innerWidth < 768) {
+      setSidebarOpen(false);
+    }
+  }, [conversationId, setSidebarOpen]);
+
   if (authLoading) {
     return (
       <div className="flex items-center justify-center h-screen">
@@ -34,14 +43,52 @@ export default function ChatPage() {
   }
 
   return (
-    <div className="flex h-screen">
-      {/* Sidebar - hidden on mobile */}
-      <div className="hidden md:block w-72 border-r border-secondary-200 bg-white">
+    <div className="flex h-screen relative">
+      {/* Mobile overlay */}
+      {sidebarOpen && (
+        <div
+          className="fixed inset-0 bg-black/30 z-20 md:hidden"
+          onClick={() => setSidebarOpen(false)}
+        />
+      )}
+
+      {/* Sidebar */}
+      <div
+        className={clsx(
+          'fixed md:relative z-30 h-full w-72 border-r border-secondary-200 bg-white transition-transform duration-300 ease-in-out',
+          sidebarOpen ? 'translate-x-0' : '-translate-x-full md:translate-x-0 md:hidden'
+        )}
+      >
         <ChatSidebar />
       </div>
 
       {/* Main chat area */}
-      <div className="flex-1 flex flex-col">
+      <div className="flex-1 flex flex-col min-w-0">
+        {/* Mobile header with menu button */}
+        <div className="flex items-center gap-3 p-3 border-b border-secondary-200 md:hidden">
+          <button
+            onClick={toggleSidebar}
+            className="p-2 hover:bg-secondary-100 rounded-lg transition-colors"
+          >
+            {sidebarOpen ? (
+              <X className="w-5 h-5 text-secondary-600" />
+            ) : (
+              <Menu className="w-5 h-5 text-secondary-600" />
+            )}
+          </button>
+          <span className="font-medium text-secondary-800">香港移民咨询</span>
+        </div>
+
+        {/* Desktop toggle button */}
+        {!sidebarOpen && (
+          <button
+            onClick={toggleSidebar}
+            className="hidden md:flex absolute left-0 top-4 z-10 p-2 bg-white border border-secondary-200 rounded-r-lg shadow-sm hover:bg-secondary-50 transition-colors"
+          >
+            <Menu className="w-5 h-5 text-secondary-600" />
+          </button>
+        )}
+
         <ChatWindow />
       </div>
     </div>
diff --git a/packages/web-client/src/features/chat/presentation/stores/chatStore.ts b/packages/web-client/src/features/chat/presentation/stores/chatStore.ts
index 4213f6c..7859daa 100644
--- a/packages/web-client/src/features/chat/presentation/stores/chatStore.ts
+++ b/packages/web-client/src/features/chat/presentation/stores/chatStore.ts
@@ -21,13 +21,20 @@ interface ChatState {
   userId: string | null;
   setUserId: (id: string) => void;
 
+  // Sidebar
+  sidebarOpen: boolean;
+  setSidebarOpen: (open: boolean) => void;
+  toggleSidebar: () => void;
+
   // Conversations
   conversations: Conversation[];
   currentConversationId: string | null;
   setConversations: (conversations: Conversation[]) => void;
   addConversation: (conversation: Conversation) => void;
+  removeConversation: (id: string) => void;
   setCurrentConversation: (id: string | null) => void;
   loadConversations: (userId: string) => Promise<void>;
+  deleteConversation: (userId: string, conversationId: string) => Promise<boolean>;
 
   // Messages
   messages: Record<string, Message[]>;
@@ -46,11 +53,16 @@ interface ChatState {
   setConnected: (connected: boolean) => void;
 }
 
-export const useChatStore = create<ChatState>((set) => ({
+export const useChatStore = create<ChatState>((set, get) => ({
   // User
   userId: null,
   setUserId: (id) => set({ userId: id }),
 
+  // Sidebar - default open on desktop
+  sidebarOpen: window.innerWidth >= 768,
+  setSidebarOpen: (open) => set({ sidebarOpen: open }),
+  toggleSidebar: () => set((state) => ({ sidebarOpen: !state.sidebarOpen })),
+
   // Conversations
   conversations: [],
   currentConversationId: null,
@@ -59,6 +71,12 @@ export const useChatStore = create<ChatState>((set) => ({
     set((state) => ({
       conversations: [conversation, ...state.conversations],
     })),
+  removeConversation: (id) =>
+    set((state) => ({
+      conversations: state.conversations.filter((c) => c.id !== id),
+      currentConversationId:
+        state.currentConversationId === id ? null : state.currentConversationId,
+    })),
   setCurrentConversation: (id) => set({ currentConversationId: id }),
   loadConversations: async (userId) => {
     try {
@@ -75,6 +93,24 @@ export const useChatStore = create<ChatState>((set) => ({
       console.error('Failed to load conversations:', error);
     }
   },
+  deleteConversation: async (userId, conversationId) => {
+    try {
+      const response = await fetch(`/api/v1/conversations/${conversationId}`, {
+        method: 'DELETE',
+        headers: {
+          'x-user-id': userId,
+        },
+      });
+      const data = await response.json();
+      if (data.success) {
+        get().removeConversation(conversationId);
+        return true;
+      }
+    } catch (error) {
+      console.error('Failed to delete conversation:', error);
+    }
+    return false;
+  },
 
   // Messages
   messages: {},