diff --git a/static/src/composables/useScrollControl.ts b/static/src/composables/useScrollControl.ts
index 07da91a..8820d5e 100644
--- a/static/src/composables/useScrollControl.ts
+++ b/static/src/composables/useScrollControl.ts
@@ -4,6 +4,7 @@ type ScrollContext = {
   getMessagesAreaElement?: () => HTMLElement | null;
   getThinkingContentElement?: (blockId: string) => HTMLElement | null;
   chatToggleScrollLockState?: () => boolean;
+  chatSetScrollState?: (payload: { autoScrollEnabled?: boolean; userScrolling?: boolean }) => void;
   thinkingScrollLocks?: Map<string, boolean>;
   _setScrollingFlag?: (value: boolean) => void;
   autoScrollEnabled?: boolean;
@@ -11,7 +12,20 @@ type ScrollContext = {
   isOutputActive?: () => boolean;
 };
 
-export function scrollToBottom(ctx: ScrollContext) {
+type ScrollOptions = {
+  ignoreUserScrolling?: boolean;
+  /**
+   * When true, force userScrolling=false after the programmatic scroll so that
+   * later自动滚动不会被“用户滚动中”状态卡住。
+   */
+  resetUserScrolling?: boolean;
+  /**
+   * Control scroll behavior; 'smooth' 用于点击滚动锁按钮时的动画滚动。
+   */
+  behavior?: ScrollBehavior;
+};
+
+export function scrollToBottom(ctx: ScrollContext, options?: ScrollOptions) {
   const messagesArea = ctx.getMessagesAreaElement?.();
   if (!messagesArea) {
     return;
@@ -19,10 +33,13 @@ export function scrollToBottom(ctx: ScrollContext) {
 
   const attempts = [0, 16, 60, 150, 320, 520]; // 多次尝试覆盖布局抖动/异步伸缩
   let cancelled = false;
+  const useSmooth =
+    options?.behavior === 'smooth' &&
+    typeof (messagesArea as HTMLElement).scrollTo === 'function';
 
   const perform = (idx: number) => {
     if (cancelled) return;
-    if (ctx.userScrolling) {
+    if (ctx.userScrolling && !options?.ignoreUserScrolling) {
       cancelled = true;
       if (typeof ctx._setScrollingFlag === 'function') {
         ctx._setScrollingFlag(false);
@@ -34,12 +51,32 @@ export function scrollToBottom(ctx: ScrollContext) {
       ctx._setScrollingFlag(true);
     }
 
-    messagesArea.scrollTop = messagesArea.scrollHeight;
+    if (useSmooth) {
+      (messagesArea as HTMLElement).scrollTo({
+        top: messagesArea.scrollHeight,
+        behavior: 'smooth'
+      });
+    } else {
+      messagesArea.scrollTop = messagesArea.scrollHeight;
+    }
 
     if (idx < attempts.length - 1) {
       setTimeout(() => perform(idx + 1), attempts[idx + 1] - attempts[idx]);
     } else if (typeof ctx._setScrollingFlag === 'function') {
       setTimeout(() => ctx._setScrollingFlag && ctx._setScrollingFlag(false), 40);
+      if (options?.resetUserScrolling) {
+        if (typeof ctx.chatSetScrollState === 'function') {
+          ctx.chatSetScrollState({ userScrolling: false });
+        } else if ('userScrolling' in ctx) {
+          ctx.userScrolling = false;
+        }
+      }
+    } else if (options?.resetUserScrolling) {
+      if (typeof ctx.chatSetScrollState === 'function') {
+        ctx.chatSetScrollState({ userScrolling: false });
+      } else if ('userScrolling' in ctx) {
+        ctx.userScrolling = false;
+      }
     }
   };
 
@@ -58,7 +95,7 @@ export function toggleScrollLock(ctx: ScrollContext) {
 
   // 没有模型输出时：允许点击，但不切换锁定，仅单次滚动到底部
   if (!active) {
-    scrollToBottom(ctx);
+    scrollToBottom(ctx, { ignoreUserScrolling: true, resetUserScrolling: true, behavior: 'smooth' });
     return ctx.autoScrollEnabled ?? false;
   }