diff --git a/static/src/App.vue b/static/src/App.vue
index 7d3cfcc..46de6d3 100644
--- a/static/src/App.vue
+++ b/static/src/App.vue
@@ -235,6 +235,7 @@
             :format-search-topic="formatSearchTopic"
             :format-search-time="formatSearchTime"
             :format-search-domains="formatSearchDomains"
+            :history-loading="historyLoading"
             @stick-state-change="handleStickStateChange"
             @user-scroll-intent="handleUserScrollIntent"
           />
diff --git a/static/src/app/methods/history.ts b/static/src/app/methods/history.ts
index c9b0dc2..e94f68b 100644
--- a/static/src/app/methods/history.ts
+++ b/static/src/app/methods/history.ts
@@ -199,7 +199,7 @@ export const historyMethods = {
 
             // 滚动到底部
             this.$nextTick(() => {
-              this.scrollToBottom();
+              this.scrollHistoryToBottomInstant();
             });
 
             debugLog('历史对话内容显示完成');
@@ -532,7 +532,7 @@ export const historyMethods = {
 
     // 确保滚动到底部
     this.$nextTick(() => {
-      this.scrollToBottom();
+      this.scrollHistoryToBottomInstant();
       setTimeout(() => {
         const blockCount =
           this.$el && this.$el.querySelectorAll
diff --git a/static/src/app/methods/ui/scroll.ts b/static/src/app/methods/ui/scroll.ts
index 27eca15..b33c4fa 100644
--- a/static/src/app/methods/ui/scroll.ts
+++ b/static/src/app/methods/ui/scroll.ts
@@ -148,6 +148,26 @@ export const scrollMethods = {
       80
     );
   },
+  scrollHistoryToBottomInstant() {
+    this._escapedByUserScroll = false;
+    const chatArea = this.getChatAreaController();
+    if (chatArea && typeof chatArea.stopStickScroll === 'function') {
+      chatArea.stopStickScroll();
+    }
+    const area = this.getMessagesAreaElement();
+    if (!area) {
+      return;
+    }
+    const jump = () => {
+      area.scrollTop = area.scrollHeight;
+    };
+    jump();
+    requestAnimationFrame(() => {
+      jump();
+      requestAnimationFrame(jump);
+    });
+    this.chatSetScrollState({ userScrolling: false });
+  },
   scrollToBottom() {
     uiBounceTrace(
       'ui.scrollToBottom:called',
diff --git a/static/src/app/methods/ui/socket.ts b/static/src/app/methods/ui/socket.ts
index 854f463..9932412 100644
--- a/static/src/app/methods/ui/socket.ts
+++ b/static/src/app/methods/ui/socket.ts
@@ -234,7 +234,6 @@ export const socketMethods = {
         throw new Error(`状态接口请求失败: ${statusResponse.status}`);
       }
       const statusData = await statusResponse.json();
-      this.isConnected = true;
       this.socket = null;
       this.projectPath = statusData.project_path || '';
       this.agentVersion = statusData.version || this.agentVersion;
@@ -296,6 +295,7 @@ export const socketMethods = {
           this.thinkingMode = false;
         }
       }
+      this.isConnected = true;
 
       const focusPromise = this.focusFetchFiles();
       let treePromise: Promise<any> | null = null;
diff --git a/static/src/components/chat/ChatArea.vue b/static/src/components/chat/ChatArea.vue
index b1f8d11..acc332a 100644
--- a/static/src/components/chat/ChatArea.vue
+++ b/static/src/components/chat/ChatArea.vue
@@ -24,7 +24,8 @@
               class="message-text user-bubble-text"
               :class="{
                 'is-collapsed': isUserBubbleCollapsed(msg, index),
-                'is-expandable': isUserBubbleExpandable(msg, index)
+                'is-expandable': isUserBubbleExpandable(msg, index),
+                'is-history-loading': props.historyLoading || userBubbleTransitionSuppressed
               }"
             >
               <div
@@ -666,6 +667,7 @@ const props = defineProps<{
   formatSearchTopic: (filters: Record<string, any>) => string;
   formatSearchTime: (filters: Record<string, any>) => string;
   formatSearchDomains: (filters: Record<string, any>) => string;
+  historyLoading?: boolean;
 }>();
 const emit = defineEmits<{
   (
@@ -715,8 +717,10 @@ const USER_BUBBLE_FOLD_LINES = 10;
 const userBubbleRefs = new Map<string, HTMLElement>();
 const userBubbleFoldStates = ref<Record<string, UserBubbleFoldState>>({});
 const copiedBubbleKeys = ref<Set<string>>(new Set());
+const userBubbleTransitionSuppressed = ref(false);
 let userBubbleResizeObserver: ResizeObserver | null = null;
 let copiedBubbleTimeouts = new Map<string, number>();
+let userBubbleTransitionSeq = 0;
 
 const getUserBubbleKey = (msg: any, index: number) => msg?.id || `user-bubble-${index}`;
 
@@ -867,6 +871,17 @@ const observeUserBubbles = () => {
   });
 };
 
+const releaseUserBubbleTransitionAfterLayout = () => {
+  const seq = ++userBubbleTransitionSeq;
+  requestAnimationFrame(() => {
+    requestAnimationFrame(() => {
+      if (seq === userBubbleTransitionSeq) {
+        userBubbleTransitionSuppressed.value = false;
+      }
+    });
+  });
+};
+
 const isSystemAutoUserMessage = (message: any) => {
   if (!message || message.role !== 'user') {
     return false;
@@ -1807,12 +1822,14 @@ function compactBriefLabel(msg: any): string {
 watch(
   () => filteredMessages.value.map((m) => m?.id ?? m?.content?.slice(0, 80)),
   () => {
+    userBubbleTransitionSuppressed.value = true;
     // 先同步估算折叠状态，再异步精确测量，避免长气泡先展开后收起
     preMeasureUserBubbles();
     nextTick(() => {
       requestAnimationFrame(() => {
         measureUserBubbles();
         observeUserBubbles();
+        releaseUserBubbleTransitionAfterLayout();
       });
     });
   },
diff --git a/static/src/stores/personalization.ts b/static/src/stores/personalization.ts
index 56e5ddb..f596627 100644
--- a/static/src/stores/personalization.ts
+++ b/static/src/stores/personalization.ts
@@ -98,6 +98,7 @@ const DEFAULT_DEEP_COMPRESS_TRIGGER_TOKENS = 150000;
 const RUN_MODE_OPTIONS: RunMode[] = ['fast', 'thinking', 'deep'];
 const EXPERIMENT_STORAGE_KEY = 'agents_personalization_experiments';
 const THEME_STORAGE_KEY = 'agents_ui_theme';
+const STACKED_HIDE_BORDERS_STORAGE_KEY = 'agents_stacked_hide_borders';
 
 const loadCachedTheme = (): PersonalForm['theme'] => {
   if (typeof window === 'undefined' || !window.localStorage) {
@@ -107,6 +108,24 @@ const loadCachedTheme = (): PersonalForm['theme'] => {
   return saved === 'light' || saved === 'dark' || saved === 'classic' ? saved : 'classic';
 };
 
+const loadCachedStackedHideBorders = (): boolean => {
+  if (typeof window === 'undefined' || !window.localStorage) {
+    return false;
+  }
+  return window.localStorage.getItem(STACKED_HIDE_BORDERS_STORAGE_KEY) === 'true';
+};
+
+const persistStackedHideBorders = (value: boolean) => {
+  if (typeof window === 'undefined' || !window.localStorage) {
+    return;
+  }
+  try {
+    window.localStorage.setItem(STACKED_HIDE_BORDERS_STORAGE_KEY, value ? 'true' : 'false');
+  } catch (error) {
+    console.warn('写入堆叠块边线设置失败：', error);
+  }
+};
+
 const defaultForm = (): PersonalForm => ({
   enabled: false,
   communication_style: 'default',
@@ -125,7 +144,7 @@ const defaultForm = (): PersonalForm => ({
   compact_message_display: 'full',
   show_git_status_bar: true,
   auto_open_terminal_panel: true,
-  stacked_hide_borders: false,
+  stacked_hide_borders: loadCachedStackedHideBorders(),
   enhanced_tool_display_categories: [],
   enabled_skills: [],
   self_identify: '',
@@ -398,6 +417,7 @@ export const usePersonalizationStore = defineStore('personalization', {
         this.applyTheme(this.form.theme);
       }
       persistDefaultHideWorkspace(this.form.default_hide_workspace);
+      persistStackedHideBorders(this.form.stacked_hide_borders);
       if (this.form.default_hide_workspace) {
         useUiStore().setWorkspaceCollapsed(true);
       }
@@ -593,6 +613,9 @@ export const usePersonalizationStore = defineStore('personalization', {
         ...this.form,
         [payload.key]: payload.value
       };
+      if (payload.key === 'stacked_hide_borders') {
+        persistStackedHideBorders(!!payload.value);
+      }
       this.clearFeedback();
       this.scheduleAutoSave();
     },
diff --git a/static/src/styles/components/chat/_chat-area.scss b/static/src/styles/components/chat/_chat-area.scss
index 7678bfc..24020e1 100644
--- a/static/src/styles/components/chat/_chat-area.scss
+++ b/static/src/styles/components/chat/_chat-area.scss
@@ -585,6 +585,10 @@
   word-break: break-all;
 }
 
+.user-message .message-text.user-bubble-text.is-history-loading .bubble-text {
+  transition: none !important;
+}
+
 .user-message .message-text.user-bubble-text.is-expandable .bubble-text:not(.is-expanded) {
   max-height: var(--bubble-fold-height, 240px);
 }