diff --git a/web/static/dev.html b/web/static/dev.html
index a29cf50..e272e23 100644
--- a/web/static/dev.html
+++ b/web/static/dev.html
@@ -350,7 +350,22 @@
   .cancelled-badge { margin-top: 8px; padding: 4px 10px; font-size: 12px; color: var(--accent); background: var(--accent-soft); border: 1px dashed var(--accent); border-radius: var(--r-md); display: inline-block; }
   .msg .role { font-size: 11px; color: var(--muted); margin-bottom: 2px; font-family: var(--mono); }
   .msg .body { word-wrap: break-word; font-size: 14px; line-height: 1.55; }
-  .msg .body.streaming::after { content: "▌"; color: var(--accent); animation: blink 1s infinite; }
+  .msg.assistant.live-run { border-color: rgba(220, 38, 38, 0.28); box-shadow: 0 0 0 1px rgba(220, 38, 38, 0.08), 0 8px 24px rgba(220, 38, 38, 0.08); }
+  .msg .body.streaming { min-width: 96px; min-height: 22px; }
+  .msg .body.streaming:empty::before { content: "思考中"; color: var(--muted); }
+  .msg .body.streaming::after {
+    content: "";
+    display: inline-block;
+    width: 1.15em;
+    height: 1.15em;
+    margin-left: 8px;
+    vertical-align: -0.18em;
+    border: 2px solid rgba(220, 38, 38, 0.18);
+    border-top-color: var(--accent);
+    border-radius: 50%;
+    animation: spin 0.8s linear infinite;
+  }
+  @keyframes spin { to { transform: rotate(360deg); } }
   @keyframes blink { 0%,49% { opacity: 1; } 50%,100% { opacity: 0; } }
   /* markdown 输出:.msg .body 与 file-preview .md-render 共用一组规则 */
   .msg .body > :first-child, .md-render > :first-child { margin-top: 0; }
@@ -1039,7 +1054,8 @@ const state = {
   // 同 wd 内除自己外其他活跃 task(run_status in running/cancelling),供 banner 显示
   concurrentWarnings: [],
   evtSrc: null,
-  streaming: false,      // 当前是否在流式中;true 时显示 stop 按钮
+  streaming: false,      // 兼容旧判断:任一 task 是否在流式中
+  liveRuns: new Map(),   // task_id -> 当前浏览器会话内运行中的回复卡/累计文本
   // task list 滚动加载 + 筛选
   taskPage: 0,           // 已加载到的最后一页(0 = 未加载)
   taskPageSize: 20,
@@ -1703,6 +1719,11 @@ async function selectTask(tid) {
     state.taskMeta = meta;
     renderChatMeta();
     await loadMessages();
+    if (meta.run_status === "running" || meta.run_status === "cancelling") {
+      ensureRunningTaskSubscribed(tid, `/v1/tasks/${tid}/events`);
+    } else {
+      renderLiveRunIfVisible();
+    }
     // 文件面板自动跳到该 task 的 working_dir(user_root 下一级子目录),
     // 不强绑定 — 用户可点 crumb 回上层看 user_root 其他目录
     const wdName = meta.working_dir ? meta.working_dir.split("/").filter(Boolean).pop() : "";
@@ -1859,11 +1880,68 @@ async function loadMessages() {
   renderMessages(data.messages);
 }
 
+function getLiveRun(taskId) {
+  return taskId ? state.liveRuns.get(taskId) : null;
+}
+
+function isCurrentTaskStreaming() {
+  return !!getLiveRun(state.taskId);
+}
+
+function createLiveAssistantCard(run) {
+  const card = document.createElement("div");
+  card.className = "msg assistant live-run";
+  card.innerHTML = `<div class="role">助手</div><div class="body streaming">${run.acc ? renderMd(run.acc) : ""}</div>`;
+  run.card = card;
+  run.body = card.querySelector(".body");
+  return card;
+}
+
+function renderLiveRunIfVisible() {
+  const run = getLiveRun(state.taskId);
+  if (!run) {
+    setActionMode("idle");
+    return;
+  }
+  const wrap = $("chat-stream");
+  const card = run.card || createLiveAssistantCard(run);
+  if (run.body && run.acc) run.body.innerHTML = renderMd(run.acc);
+  if (card.parentElement !== wrap) wrap.appendChild(card);
+  wrap.scrollTop = wrap.scrollHeight;
+  setActionMode(run.cancelling ? "cancelling" : "streaming");
+  $("chat-hint").textContent = run.cancelling ? "停止中…" : "接收中…";
+}
+
+function ensureRunningTaskSubscribed(taskId, url) {
+  if (!taskId || getLiveRun(taskId)) return;
+  const run = {
+    taskId,
+    url,
+    acc: "",
+    pending: false,
+    seenRels: new Set(),
+    terminal: false,
+    card: null,
+    body: null,
+    cancelling: state.taskMeta && state.taskMeta.run_status === "cancelling",
+    workingDir: state.taskMeta && state.taskMeta.working_dir,
+  };
+  state.liveRuns.set(taskId, run);
+  state.streaming = true;
+  renderLiveRunIfVisible();
+  streamSse(url, run);
+}
+
+function setRunHint(run, text) {
+  if (state.taskId === run.taskId) $("chat-hint").textContent = text;
+}
+
 function renderMessages(msgs) {
   const wrap = $("chat-stream");
   wrap.innerHTML = "";
   if (!msgs.length) {
     wrap.innerHTML = `<div class="empty">(暂无消息 · 在下方输入开始对话)</div>`;
+    renderLiveRunIfVisible();
     return;
   }
   // 模型切换点小标:assistant 行的 model_profile 与上一个 assistant 不同就插一行分隔
@@ -1949,6 +2027,7 @@ function renderMessages(msgs) {
   }
   wrap.scrollTop = wrap.scrollHeight;
   upgradeMediaArtifacts(wrap);
+  renderLiveRunIfVisible();
 }
 
 // ───── send + SSE ─────
@@ -1975,7 +2054,7 @@ function setActionMode(mode) {
 }
 
 function chatAction() {
-  if (state.streaming) cancelCurrentTask();
+  if (isCurrentTaskStreaming()) cancelCurrentTask();
   else sendMessage();
 }
 
@@ -1984,7 +2063,7 @@ $("chat-input").addEventListener("keydown", (e) => {
   // streaming 期间 Enter 不触发停止 —— 用户可能正在编辑下一条草稿,误触发风险高
   if (e.key === "Enter" && !e.shiftKey) {
     e.preventDefault();
-    if (!state.streaming) sendMessage();
+    if (!isCurrentTaskStreaming()) sendMessage();
   }
 });
 $("chat-input").addEventListener("input", syncOptimizeBtn);
@@ -2127,11 +2206,12 @@ $("chat-stream").addEventListener("click", (e) => {
 
 async function sendMessage() {
   if (!state.taskId) return;
-  if (state.streaming) return;
+  if (isCurrentTaskStreaming()) return;
   const content = $("chat-input").value.trim();
   if (!content) return;
   setActionMode("cancelling");  // 临时锁住,等 events_url 拿到再切 streaming
   $("chat-hint").textContent = "发送中…";
+  const taskId = state.taskId;
   try {
     // 立刻渲染 user 消息卡(乐观)
     const wrap = $("chat-stream");
@@ -2142,21 +2222,34 @@ async function sendMessage() {
 
     // assistant 流式占位卡
     const asstCard = document.createElement("div");
-    asstCard.className = "msg assistant";
+    asstCard.className = "msg assistant live-run";
     asstCard.innerHTML = `<div class="role">助手</div><div class="body streaming"></div>`;
     wrap.appendChild(asstCard);
     wrap.scrollTop = wrap.scrollHeight;
 
-    const r = await api("POST", `/v1/tasks/${state.taskId}/messages`, {
+    const r = await api("POST", `/v1/tasks/${taskId}/messages`, {
       content,
       image_model: state.imageModel || "",
       video_model: state.videoModel || "",
     });
     $("chat-input").value = "";
     syncOptimizeBtn();
+    const run = {
+      taskId,
+      url: r.events_url,
+      acc: "",
+      pending: false,
+      seenRels: new Set(),
+      terminal: false,
+      card: asstCard,
+      body: asstCard.querySelector(".body"),
+      cancelling: false,
+      workingDir: state.taskMeta && state.taskMeta.working_dir,
+    };
+    state.liveRuns.set(taskId, run);
     state.streaming = true;
     setActionMode("streaming");
-    streamSse(r.events_url, asstCard);
+    streamSse(r.events_url, run);
   } catch (e) {
     if (e.status === 401) { logout(); return; }
     appendErrorCard(e.message);
@@ -2166,7 +2259,9 @@ async function sendMessage() {
 }
 
 async function cancelCurrentTask() {
-  if (!state.taskId || !state.streaming) return;
+  const run = getLiveRun(state.taskId);
+  if (!state.taskId || !run) return;
+  run.cancelling = true;
   setActionMode("cancelling");
   $("chat-hint").textContent = "停止中…";
   try {
@@ -2176,21 +2271,37 @@ async function cancelCurrentTask() {
     if (e.status === 401) { logout(); return; }
     // 409 = 已结束 / 已 cancelling,不算错;其他贴 toast
     if (e.status !== 409) appendErrorCard("cancel: " + e.message);
+    run.cancelling = false;
     setActionMode("streaming");
     $("chat-hint").textContent = "接收中…";
   }
 }
 
-function streamSse(url, asstCard) {
+function streamSse(url, run) {
   // EventSource 不支持自定义 header,token 走 query string(?token=...)
   // 这里 SSE 走 same-origin,token 经 URL 传给后端 — 但当前后端只读 Authorization 头
   // 简单做法:走带 token 的 fetch + ReadableStream 替代 EventSource
-  fetchSse(url, asstCard).catch((e) => appendErrorCard("sse: " + e.message));
+  fetchSse(url, run).catch((e) => {
+    appendRunError(run, "sse: " + e.message);
+  });
 }
 
-async function fetchSse(url, asstCard) {
-  const body = asstCard.querySelector(".body");
-  const ctx = { acc: "", body, pending: false, seenRels: new Set(), terminal: false };
+function appendRunError(run, msg) {
+  if (state.taskId === run.taskId) {
+    appendErrorCard(msg);
+    return;
+  }
+  const host = run.card || createLiveAssistantCard(run);
+  const card = document.createElement("div");
+  card.className = "msg error";
+  card.innerHTML = `<div class="role">错误</div><div class="body">${escapeHtml(msg)}</div>`;
+  host.appendChild(card);
+}
+
+async function fetchSse(url, run) {
+  const body = run.body || (run.card && run.card.querySelector(".body"));
+  run.body = body;
+  const ctx = run;
   const hint = $("chat-hint");
   // 重连:reader 异常 / 自然 EOF 但未收到 done/error 时,GET events 重订阅。
   // 后端 stream_events 重连入口会校验 run_status,task 已不活跃直接吐 done 关流;
@@ -2200,14 +2311,14 @@ async function fetchSse(url, asstCard) {
   try {
     while (true) {
       try {
-        await consumeSseStream(url, asstCard, ctx);
+        await consumeSseStream(url, run.card, ctx);
       } catch (e) {
         if (ctx.terminal) break;  // 已收到 done/error,不重连
         if (attempt >= backoffs.length) {
-          appendErrorCard("连接已断开,刚才的回复可能未完成,请重发消息。");
+          appendRunError(ctx, "连接已断开,刚才的回复可能未完成,请重发消息。");
           break;
         }
-        hint.textContent = `连接断开,重连中…(${attempt + 1}/${backoffs.length})`;
+        setRunHint(ctx, `连接断开,重连中…(${attempt + 1}/${backoffs.length})`);
         await new Promise(r => setTimeout(r, backoffs[attempt]));
         attempt++;
         continue;
@@ -2216,27 +2327,34 @@ async function fetchSse(url, asstCard) {
       if (ctx.terminal) break;  // 正常收尾(看到 done/error)
       // 未见 done/error 就 EOF → 服务端中途关流(进程被杀 / nginx 切),重连
       if (attempt >= backoffs.length) {
-        appendErrorCard("连接已断开,刚才的回复可能未完成,请重发消息。");
+        appendRunError(ctx, "连接已断开,刚才的回复可能未完成,请重发消息。");
         break;
       }
-      hint.textContent = `连接断开,重连中…(${attempt + 1}/${backoffs.length})`;
+      setRunHint(ctx, `连接断开,重连中…(${attempt + 1}/${backoffs.length})`);
       await new Promise(r => setTimeout(r, backoffs[attempt]));
       attempt++;
     }
     // 最终定稿 + 代码高亮(流式中不 highlight,省 CPU)
-    body.innerHTML = renderMd(ctx.acc);
-    highlightIn(asstCard);
+    if (ctx.body) {
+      ctx.body.innerHTML = renderMd(ctx.acc);
+      if (ctx.card) highlightIn(ctx.card);
+    }
   } finally {
-    body.classList.remove("streaming");
-    hint.textContent = "就绪";
-    state.streaming = false;
-    setActionMode("idle");
+    if (ctx.body) ctx.body.classList.remove("streaming");
+    state.liveRuns.delete(ctx.taskId);
+    state.streaming = state.liveRuns.size > 0;
+    if (state.taskId === ctx.taskId) {
+      hint.textContent = "就绪";
+      setActionMode("idle");
+    }
   }
   // 刷新 task meta + messages(拿真实持久化的);失败路径已退出,这里不再跑
   loadTaskList();
-  await loadMessages();
-  loadFiles();  // 回复结束后右侧文件面板同步刷新(可能有新写入 / 修改的产物)
-  refreshConcurrentWarnings();  // 自己 task 收尾,顺便清/更新 banner(同 wd 邻居可能也变了)
+  if (state.taskId === ctx.taskId) {
+    await loadMessages();
+    loadFiles();  // 回复结束后右侧文件面板同步刷新(可能有新写入 / 修改的产物)
+    refreshConcurrentWarnings();  // 自己 task 收尾,顺便清/更新 banner(同 wd 邻居可能也变了)
+  }
 }
 
 async function consumeSseStream(url, asstCard, ctx) {
@@ -2247,7 +2365,7 @@ async function consumeSseStream(url, asstCard, ctx) {
   const reader = r.body.getReader();
   const dec = new TextDecoder();
   let buf = "";
-  $("chat-hint").textContent = "接收中…";
+  setRunHint(ctx, "接收中…");
   while (true) {
     const { value, done } = await reader.read();
     if (done) return;
@@ -2285,9 +2403,13 @@ function parseSseFrame(frame) {
 
 function handleSseEvent(ev, asstCard, ctx) {
   const t = ev.event;
+  asstCard = asstCard || ctx.card || createLiveAssistantCard(ctx);
+  ctx.card = asstCard;
+  ctx.body = ctx.body || asstCard.querySelector(".body");
   const stream = $("chat-stream");
+  const visible = state.taskId === ctx.taskId;
   // 用户拖到上面看历史时不抢滚动,只在贴底时跟流
-  const nearBottom = stream.scrollHeight - stream.scrollTop - stream.clientHeight < 120;
+  const nearBottom = visible && (stream.scrollHeight - stream.scrollTop - stream.clientHeight < 120);
   if (t === "text" && ev.data && ev.data.delta) {
     ctx.acc += ev.data.delta;
     // rAF 节流:每帧最多 1 次重渲染,流式 token 高频时不抖
@@ -2307,7 +2429,7 @@ function handleSseEvent(ev, asstCard, ctx) {
     det.className = "tool-call";
     det.innerHTML = `<summary>工具调用:${escapeHtml(fn)}</summary><pre>${escapeHtml(argsStr)}</pre>`;
     asstCard.appendChild(det);
-    const wd = _workingDirName(state.taskMeta && state.taskMeta.working_dir);
+    const wd = _workingDirName(ctx.workingDir);
     const isProducer = ARTIFACT_PRODUCING_TOOLS.has(fn);
     const fresh = isProducer
       ? extractArtifactRels(argsStr, wd).filter(r => !ctx.seenRels.has(r))
@@ -2327,7 +2449,7 @@ function handleSseEvent(ev, asstCard, ctx) {
     det.className = "tool-call";
     det.innerHTML = `<summary>工具结果${banner}</summary><pre>${escapeHtml(txtStr)}</pre>`;
     asstCard.appendChild(det);
-    const wd = _workingDirName(state.taskMeta && state.taskMeta.working_dir);
+    const wd = _workingDirName(ctx.workingDir);
     const isProducer = ARTIFACT_PRODUCING_TOOLS.has(toolName);
     const fresh = isProducer
       ? extractArtifactRels(txtStr, wd).filter(r => !ctx.seenRels.has(r))
@@ -2338,7 +2460,7 @@ function handleSseEvent(ev, asstCard, ctx) {
       asstCard.insertAdjacentHTML("beforeend", barHtml);
       if (isProducer) upgradeMediaArtifacts(asstCard);
     }
-    scheduleFilesRefresh();  // 工具调用结果回来,FS 可能被改了,debounce 刷新右侧
+    if (visible) scheduleFilesRefresh();  // 工具调用结果回来,FS 可能被改了,debounce 刷新右侧
   } else if (t === "cancelled") {
     const badge = document.createElement("div");
     badge.className = "cancelled-badge";
@@ -2346,7 +2468,7 @@ function handleSseEvent(ev, asstCard, ctx) {
     asstCard.appendChild(badge);
   } else if (t === "error") {
     const msg = (ev.data && (ev.data.msg || ev.data.error)) || JSON.stringify(ev.data);
-    appendErrorCard(msg);
+    appendRunError(ctx, msg);
   }
   if (nearBottom) stream.scrollTop = stream.scrollHeight;
 }