diff --git a/apps/desktop/src/renderer/src/components/ChatView.tsx b/apps/desktop/src/renderer/src/components/ChatView.tsx
index 8b03e28..5712caa 100644
--- a/apps/desktop/src/renderer/src/components/ChatView.tsx
+++ b/apps/desktop/src/renderer/src/components/ChatView.tsx
@@ -118,9 +118,13 @@ export function ChatView({
 
   useEffect(() => {
     const el = scrollRef.current
-    if (el && pinnedRef.current) {
+    if (!el || !pinnedRef.current) return
+    // rAF 合帧：流式 delta 一帧内多次触发时只吸底一次，
+    // 且读 scrollHeight 的强制布局每帧至多一次
+    const raf = requestAnimationFrame(() => {
       el.scrollTop = el.scrollHeight
-    }
+    })
+    return () => cancelAnimationFrame(raf)
   }, [messages, tools, streaming])
 
   const hasContent = messages.length > 0
diff --git a/apps/desktop/src/renderer/src/components/Markdown.tsx b/apps/desktop/src/renderer/src/components/Markdown.tsx
index b1d2f80..6337fbd 100644
--- a/apps/desktop/src/renderer/src/components/Markdown.tsx
+++ b/apps/desktop/src/renderer/src/components/Markdown.tsx
@@ -1,4 +1,4 @@
-import { useEffect, useState, type ReactNode } from 'react'
+import { memo, useEffect, useState, type ReactNode } from 'react'
 import ReactMarkdown, { type Components } from 'react-markdown'
 import remarkGfm from 'remark-gfm'
 import {
@@ -261,7 +261,7 @@ function BlockView({ blockMatch }: { blockMatch: BlockMatch }): ReactNode {
   return <Component blockMatch={blockMatch} />
 }
 
-export function Markdown({ text, streaming = false }: { text: string; streaming?: boolean }): ReactNode {
+function MarkdownBase({ text, streaming = false }: { text: string; streaming?: boolean }): ReactNode {
   // 流式开启时 llm-ui 逐块渐进解析（未闭合围栏 → partial code block，未完段落 → partial markdown），
   // 已完成的块会被 lookBack 冻结不再重渲染；流式结束后整体收敛为最终形态
   const { blockMatches } = useLLMOutput({
@@ -279,3 +279,7 @@ export function Markdown({ text, streaming = false }: { text: string; streaming?
     </>
   )
 }
+
+/** memo：流式 delta 会让整份消息列表重渲染，历史消息的 text/streaming 不变，
+ * 直接跳过 react-markdown 的整棵 vdom diff —— 这是流式卡顿的大头。 */
+export const Markdown = memo(MarkdownBase)
diff --git a/apps/desktop/src/renderer/src/components/MessageItem.tsx b/apps/desktop/src/renderer/src/components/MessageItem.tsx
index 170be65..dcf85e6 100644
--- a/apps/desktop/src/renderer/src/components/MessageItem.tsx
+++ b/apps/desktop/src/renderer/src/components/MessageItem.tsx
@@ -1,5 +1,6 @@
-import { useEffect, useRef, useState, type ReactNode } from 'react'
+import { useEffect, useLayoutEffect, useRef, useState, type ReactNode } from 'react'
 import type { ApprovalRequest, ToolState, UiMessage } from '../hooks/useAgent'
+import { animateCollapse, animateExpand } from '../lib/anim'
 import { Markdown } from './Markdown'
 import { Loading } from './Loading'
 import { StreamingText } from './StreamingText'
@@ -169,6 +170,30 @@ export function AssistantTurn({
     prevTurnActive.current = turnActive
   }, [turnActive])
 
+  // 过程区折叠/展开：GSAP 高度 + 透明度补间（可中断续接）。内联高度完全由
+  // 动画层持有，React 不渲染 style，避免重渲染时清掉补间中的值。
+  // 首帧直接落位（历史回合默认收起），不播动画。
+  const processRef = useRef<HTMLDivElement | null>(null)
+  const prevCollapsedRef = useRef<boolean | null>(null)
+  useLayoutEffect(() => {
+    const el = processRef.current
+    if (!el) return
+    const effective = collapsed && hasProcess
+    const prev = prevCollapsedRef.current
+    prevCollapsedRef.current = effective
+    if (prev === null) {
+      if (effective) {
+        el.style.height = '0px'
+        el.style.opacity = '0'
+        el.style.pointerEvents = 'none'
+      }
+      return
+    }
+    if (prev === effective) return
+    if (effective) animateCollapse(el)
+    else animateExpand(el)
+  }, [collapsed, hasProcess])
+
   const workedFor = useWorkingSeconds(turnActive)
   const headerLabel = workedFor || `${calls} 次工具调用${thinking ? `，${thinking} 条消息` : ''}`
 
@@ -239,21 +264,9 @@ export function AssistantTurn({
         </div>
       )}
 
-      {/* 过程区：grid-rows 0fr/1fr 高度动画 + 透明度渐隐，收起/展开更从容 */}
-      <div
-        aria-hidden={collapsed && hasProcess}
-        className={`grid transition-[grid-template-rows] duration-500 ease-in-out ${
-          collapsed && hasProcess ? 'pointer-events-none' : ''
-        }`}
-        style={{ gridTemplateRows: collapsed && hasProcess ? '0fr' : '1fr' }}
-      >
-        <div
-          className={`min-h-0 overflow-hidden transition-opacity duration-300 ${
-            collapsed && hasProcess ? 'opacity-0' : 'opacity-100'
-          }`}
-        >
-          {processNodes}
-        </div>
+      {/* 过程区：GSAP 高度 + 透明度补间（见上方 useLayoutEffect） */}
+      <div ref={processRef} aria-hidden={collapsed && hasProcess} className="overflow-hidden">
+        {processNodes}
       </div>
 
       {/* 答案区：最终正文 / 流式中的答案雏形，始终可见 */}
diff --git a/apps/desktop/src/renderer/src/components/Thinking.tsx b/apps/desktop/src/renderer/src/components/Thinking.tsx
index ff26c14..aee9850 100644
--- a/apps/desktop/src/renderer/src/components/Thinking.tsx
+++ b/apps/desktop/src/renderer/src/components/Thinking.tsx
@@ -30,13 +30,7 @@ export function Thinking({
   }, [rows, expanded])
 
   return (
-    <div
-      className="flex w-full max-w-95 flex-col"
-      style={{
-        minHeight: expanded ? Math.min(60 + rows.length * 28, 220) : undefined,
-        transition: 'min-height 400ms ease'
-      }}
-    >
+    <div className="flex w-full max-w-95 flex-col" style={{ minHeight: expanded ? 60 : undefined }}>
       {/* 表头：状态词 + 旋转箭头 */}
       <button
         type="button"
diff --git a/apps/desktop/src/renderer/src/hooks/useEntrance.ts b/apps/desktop/src/renderer/src/hooks/useEntrance.ts
index a1a9be1..9c54739 100644
--- a/apps/desktop/src/renderer/src/hooks/useEntrance.ts
+++ b/apps/desktop/src/renderer/src/hooks/useEntrance.ts
@@ -1,26 +1,13 @@
 import { useEffect, useRef } from 'react'
 import type { RefObject } from 'react'
+import { animateEntrance } from '../lib/anim'
 
 /** 流式消息的入场动画（GSAP），仅挂载时执行一次 */
 export function useEntrance<T extends HTMLElement>(): RefObject<T | null> {
   const ref = useRef<T | null>(null)
   useEffect(() => {
     const el = ref.current
-    if (!el) return
-    let tween: { kill(): void } | null = null
-    let cancelled = false
-    void import('gsap').then((gsapModule) => {
-      if (cancelled) return
-      tween = gsapModule.gsap.fromTo(
-        el,
-        { opacity: 0, y: 10 },
-        { opacity: 1, y: 0, duration: 0.4, ease: 'power2.out', clearProps: 'transform' }
-      )
-    })
-    return () => {
-      cancelled = true
-      tween?.kill()
-    }
+    if (el) animateEntrance(el)
   }, [])
   return ref
 }
diff --git a/apps/desktop/src/renderer/src/lib/anim.ts b/apps/desktop/src/renderer/src/lib/anim.ts
new file mode 100644
index 0000000..60b44a7
--- /dev/null
+++ b/apps/desktop/src/renderer/src/lib/anim.ts
@@ -0,0 +1,84 @@
+/** 共享动画模块（GSAP 懒加载单例）。
+ * 原则：transform/opacity 小动画交给 CSS 合成器；GSAP 负责需要中断衔接、
+ * 按内容测量的补间（消息入场、回合过程区折叠/展开）。
+ * 全部遵循系统「减弱动态效果」（prefers-reduced-motion）。 */
+
+type Gsap = (typeof import('gsap'))['gsap']
+
+let gsapPromise: Promise<Gsap> | null = null
+
+function loadGsap(): Promise<Gsap> {
+  gsapPromise ??= import('gsap').then((m) => {
+    m.gsap.defaults({ overwrite: 'auto' })
+    return m.gsap
+  })
+  return gsapPromise
+}
+
+function reducedMotion(): boolean {
+  return window.matchMedia('(prefers-reduced-motion: reduce)').matches
+}
+
+/** 消息入场：上移淡入，仅挂载时一次 */
+export function animateEntrance(el: HTMLElement): void {
+  if (reducedMotion()) return
+  void loadGsap().then((gsap) => {
+    gsap.fromTo(
+      el,
+      { opacity: 0, y: 10 },
+      { opacity: 1, y: 0, duration: 0.4, ease: 'power2.out', clearProps: 'transform' }
+    )
+  })
+}
+
+/** 收起：高度 → 0、透明度 → 0。先同步落起始帧再异步补间，中间不闪帧；
+ * 从当前高度续接（可中断重入，快速反复点击也顺滑）。 */
+export function animateCollapse(el: HTMLElement): void {
+  el.style.pointerEvents = ''
+  if (reducedMotion()) {
+    el.style.height = '0px'
+    el.style.opacity = '0'
+    el.style.pointerEvents = 'none'
+    return
+  }
+  const from = el.offsetHeight
+  el.style.height = `${from}px`
+  void loadGsap().then((gsap) => {
+    gsap.killTweensOf(el)
+    gsap.to(el, {
+      height: 0,
+      opacity: 0,
+      duration: 0.5,
+      ease: 'power2.inOut',
+      onComplete: () => {
+        el.style.pointerEvents = 'none'
+      }
+    })
+  })
+}
+
+/** 展开：高度 0 → 内容实际高度，完成后复位 auto，后续内容增长不被裁剪 */
+export function animateExpand(el: HTMLElement): void {
+  el.style.height = 'auto'
+  el.style.pointerEvents = ''
+  const to = el.offsetHeight
+  if (reducedMotion()) {
+    el.style.height = ''
+    el.style.opacity = ''
+    return
+  }
+  el.style.height = '0px'
+  void loadGsap().then((gsap) => {
+    gsap.killTweensOf(el)
+    gsap.to(el, {
+      height: to,
+      opacity: 1,
+      duration: 0.5,
+      ease: 'power2.inOut',
+      onComplete: () => {
+        el.style.height = ''
+        el.style.opacity = ''
+      }
+    })
+  })
+}