diff --git a/README.md b/README.md
index 319954b..96cc115 100644
--- a/README.md
+++ b/README.md
@@ -14,7 +14,7 @@
 
 译读（ImmerRead）是一款本地安装的 Chrome Side Panel 扩展，为**各类英文文章**（技术博客、新闻报道、深度长文、Substack newsletter 等）提供沉浸式的整篇中文阅读体验。它在右侧渐进翻译全文，提供章节导读、划词翻译与解释、自定义术语库，并把密钥和缓存保存在你自己的浏览器中。
 
-**已验证（2026-09-17）：** `npm test` 32/32 通过，`npm run check` 通过。项目使用原生 HTML、CSS 和 JavaScript，无构建步骤。
+**已验证（2026-09-17）：** `npm test` 34/34 通过，`npm run check` 通过。项目使用原生 HTML、CSS 和 JavaScript，无构建步骤。
 
 ## 为什么是译读
 
@@ -30,7 +30,7 @@
 | 沉浸式双语阅读 | 中文译文与英文原文各自完整，滚动原文时译文自动定位到对应段落 |
 | 自定义术语库 | 固定自己认可的译法，跨文章复用，只重翻受影响的段落 |
 | 章节导读 | 按原文章节生成中文标题和最多三句、150 字的概述，先把握全局再深入 |
-| 划词助学 | 在原文选中英文，可即时翻译或让 LLM 结合语境解释，顺手存为固定译法 |
+| 划词助学 | 在原文选中英文，可即时翻译或让 LLM 结合语境解释，顺手存为固定译法；仅在侧栏打开时启用 |
 | 复杂内容保护 | 图片、图表、视频和交互模块留在原网页；可识别的表格叶子单元格在原位显示小号译文 |
 | 本地缓存 | 译文和导读最多缓存 20 篇文章、保留 30 天，可随时清除 |
 | 一致排版 | 右侧译文统一为纯文本，避免链接、粗体等原文样式被模型随机继承 |
@@ -145,7 +145,7 @@ Most translation tools mix the two languages on screen: overlaid paragraphs, ins
 - Immersive bilingual reading: scroll the source and the translation follows paragraph by paragraph.
 - A custom terminology glossary: pin your preferred translations, reused across articles, retranslating only affected paragraphs.
 - Section-based reading guides: Chinese titles and summaries of at most three sentences / 150 characters per section.
-- Learning aids on selection: translate or ask the LLM to explain selected English in context, and save terms to your glossary.
+- Learning aids on selection: translate or ask the LLM to explain selected English in context, and save terms to your glossary. Active only while the side panel is open.
 - Local translation and guide caches with a 20-article / 30-day limit.
 - Plain-text translation rendering for consistent and safe typography.
 - No account, developer-operated backend, analytics, advertising, or telemetry.
@@ -175,7 +175,7 @@ npm test
 npm run check
 ```
 
-Verified on 2026-09-17: 32 tests passed and syntax checks passed. The project uses plain HTML, CSS, and JavaScript with no build step.
+Verified on 2026-09-17: 34 tests passed and syntax checks passed. The project uses plain HTML, CSS, and JavaScript with no build step.
 
 ## License
 
diff --git a/background.js b/background.js
index 7bbff00..4c06265 100644
--- a/background.js
+++ b/background.js
@@ -19,17 +19,40 @@ let summaryWriteChain = Promise.resolve();
 
 void chrome.sidePanel.setPanelBehavior({ openPanelOnActionClick: true }).catch(() => undefined);
 
+const panelOpenTabs = new Set();
+
+chrome.runtime.onConnect.addListener((port) => {
+  const match = /^yidu-panel-open:(\d+)$/.exec(port.name || "");
+  if (!match) return;
+  const tabId = Number(match[1]);
+  panelOpenTabs.add(tabId);
+  notifyPanelState(tabId, true);
+  port.onDisconnect.addListener(() => {
+    panelOpenTabs.delete(tabId);
+    notifyPanelState(tabId, false);
+  });
+});
+
+function notifyPanelState(tabId, open) {
+  chrome.tabs.sendMessage(tabId, { type: "YIDU_PANEL_STATE", payload: { open } }).catch(() => undefined);
+}
+
 chrome.runtime.onInstalled.addListener((details) => {
   if (details.reason === "install") void chrome.runtime.openOptionsPage();
 });
 
-chrome.runtime.onMessage.addListener((message, _sender, sendResponse) => {
+chrome.runtime.onMessage.addListener((message, sender, sendResponse) => {
   if (message?.type === "YIDU_OPEN_OPTIONS") {
     chrome.runtime.openOptionsPage();
     sendResponse({ ok: true });
     return false;
   }
 
+  if (message?.type === "YIDU_PANEL_STATE_QUERY") {
+    sendResponse({ ok: true, open: panelOpenTabs.has(sender.tab?.id) });
+    return false;
+  }
+
   const handlers = {
     YIDU_PREPARE_TAB: prepareTab,
     YIDU_TRANSLATE_BATCH: translateBatch,
diff --git a/content.js b/content.js
index d0f3af3..d220458 100644
--- a/content.js
+++ b/content.js
@@ -13,6 +13,12 @@
   let cellNotes = new Map();
 
   chrome.runtime.onMessage.addListener((message, _sender, sendResponse) => {
+    if (message?.type === "YIDU_PANEL_STATE") {
+      panelOpen = Boolean(message.payload?.open);
+      if (!panelOpen) hideSelectionUi();
+      sendResponse({ ok: true });
+      return false;
+    }
     if (message?.type === "YIDU_REQUEST_SCROLL_SYNC") {
       scheduleScrollSync();
       sendResponse({ ok: true });
@@ -341,6 +347,15 @@
   let selectedText = "";
   let selectedRect = null;
   let requestId = 0;
+  let panelOpen = false;
+
+  try {
+    void chrome.runtime.sendMessage({ type: "YIDU_PANEL_STATE_QUERY" })
+      .then((response) => { panelOpen = Boolean(response?.open); })
+      .catch(() => undefined);
+  } catch {
+    // 扩展上下文失效时保持浮窗关闭。
+  }
 
   document.addEventListener("mouseup", onSelectionChange);
   document.addEventListener("keyup", (event) => {
@@ -359,6 +374,10 @@
   function onSelectionChange(event) {
     if (event?.target && selectionRoot?.contains(event.target)) return;
     emitSelectionSync();
+    if (!panelOpen) {
+      hideSelectionUi();
+      return;
+    }
     if (selectionShadow?.querySelector(".yidu-result")) return;
     const selection = window.getSelection();
     const text = (selection?.toString() || "").replace(/\s+/g, " ").trim();
diff --git a/sidepanel.js b/sidepanel.js
index 68c60c9..1e96c8b 100644
--- a/sidepanel.js
+++ b/sidepanel.js
@@ -1,654 +1,665 @@
-import { containsTerm } from "./lib/glossary.js";
-import { groupArticleModules } from "./lib/summary.js";
-
-(() => {
-  const BATCH_SIZE = 4;
-  const VIEWPORT_MARGIN = "520px 0px";
-  const content = document.getElementById("content");
-  const status = document.getElementById("status");
-  const summaryContent = document.getElementById("summary-content");
-  const glossaryForm = document.getElementById("glossary-form");
-  const glossarySource = document.getElementById("glossary-source");
-  const glossaryTarget = document.getElementById("glossary-target");
-  const glossaryList = document.getElementById("glossary-list");
-  const glossaryStatus = document.getElementById("glossary-status");
-  const glossaryCancel = document.getElementById("glossary-cancel");
-  const views = {
-    translation: document.getElementById("view-translation"),
-    summary: document.getElementById("view-summary"),
-    glossary: document.getElementById("view-glossary")
-  };
-  const tabs = {
-    translation: document.getElementById("tab-translation"),
-    summary: document.getElementById("tab-summary"),
-    glossary: document.getElementById("tab-glossary")
-  };
-  let activeView = "translation";
-  let editingSource = "";
-  let session = null;
+import { containsTerm } from "./lib/glossary.js";
+import { groupArticleModules } from "./lib/summary.js";
+
+(() => {
+  const BATCH_SIZE = 4;
+  const VIEWPORT_MARGIN = "520px 0px";
+  const content = document.getElementById("content");
+  const status = document.getElementById("status");
+  const summaryContent = document.getElementById("summary-content");
+  const glossaryForm = document.getElementById("glossary-form");
+  const glossarySource = document.getElementById("glossary-source");
+  const glossaryTarget = document.getElementById("glossary-target");
+  const glossaryList = document.getElementById("glossary-list");
+  const glossaryStatus = document.getElementById("glossary-status");
+  const glossaryCancel = document.getElementById("glossary-cancel");
+  const views = {
+    translation: document.getElementById("view-translation"),
+    summary: document.getElementById("view-summary"),
+    glossary: document.getElementById("view-glossary")
+  };
+  const tabs = {
+    translation: document.getElementById("tab-translation"),
+    summary: document.getElementById("tab-summary"),
+    glossary: document.getElementById("tab-glossary")
+  };
+  let activeView = "translation";
+  let editingSource = "";
+  let session = null;
   let reloadTimer = 0;
-
-  document.getElementById("settings").addEventListener("click", () => {
-    chrome.runtime.sendMessage({ type: "YIDU_OPEN_OPTIONS" });
-  });
-  for (const [name, tab] of Object.entries(tabs)) {
-    tab.addEventListener("click", () => selectView(name));
-    tab.addEventListener("keydown", (event) => {
-      const names = Object.keys(tabs);
-      const index = names.indexOf(name);
-      const next = event.key === "ArrowRight" ? names[(index + 1) % names.length]
-        : event.key === "ArrowLeft" ? names[(index + names.length - 1) % names.length]
-        : event.key === "Home" ? names[0] : event.key === "End" ? names[names.length - 1] : "";
-      if (!next) return;
-      event.preventDefault();
-      selectView(next);
-      tabs[next].focus();
-    });
-  }
-  glossaryForm.addEventListener("submit", saveGlossaryFromForm);
-  glossaryCancel.addEventListener("click", resetGlossaryForm);
-  chrome.tabs.onActivated.addListener(scheduleReload);
-  chrome.tabs.onUpdated.addListener((_tabId, changeInfo, tab) => {
-    if (changeInfo.status === "complete" && tab.active) scheduleReload();
-  });
-  chrome.runtime.onMessage.addListener((message, sender) => {
-    if (message?.type === "YIDU_SOURCE_SCROLL") handleSourceScroll(message.payload, sender.tab?.id);
-    if (message?.type === "YIDU_SOURCE_SELECTION") handleSourceSelection(message.payload, sender.tab?.id);
-    if (message?.type === "YIDU_GLOSSARY_CHANGED") handleGlossaryChanged(message.payload);
-    return false;
-  });
-
+  let panelPort = null;

+
+  document.getElementById("settings").addEventListener("click", () => {
+    chrome.runtime.sendMessage({ type: "YIDU_OPEN_OPTIONS" });
+  });
+  for (const [name, tab] of Object.entries(tabs)) {
+    tab.addEventListener("click", () => selectView(name));
+    tab.addEventListener("keydown", (event) => {
+      const names = Object.keys(tabs);
+      const index = names.indexOf(name);
+      const next = event.key === "ArrowRight" ? names[(index + 1) % names.length]
+        : event.key === "ArrowLeft" ? names[(index + names.length - 1) % names.length]
+        : event.key === "Home" ? names[0] : event.key === "End" ? names[names.length - 1] : "";
+      if (!next) return;
+      event.preventDefault();
+      selectView(next);
+      tabs[next].focus();
+    });
+  }
+  glossaryForm.addEventListener("submit", saveGlossaryFromForm);
+  glossaryCancel.addEventListener("click", resetGlossaryForm);
+  chrome.tabs.onActivated.addListener(scheduleReload);
+  chrome.tabs.onUpdated.addListener((_tabId, changeInfo, tab) => {
+    if (changeInfo.status === "complete" && tab.active) scheduleReload();
+  });
+  chrome.runtime.onMessage.addListener((message, sender) => {
+    if (message?.type === "YIDU_SOURCE_SCROLL") handleSourceScroll(message.payload, sender.tab?.id);
+    if (message?.type === "YIDU_SOURCE_SELECTION") handleSourceSelection(message.payload, sender.tab?.id);
+    if (message?.type === "YIDU_GLOSSARY_CHANGED") handleGlossaryChanged(message.payload);
+    return false;
+  });
+
+  void announcePanelOpen();
   void loadActiveArticle();
 
-  function selectView(name) {
-    activeView = name;
-    for (const [key, view] of Object.entries(views)) {
-      const selected = key === name;
-      view.hidden = !selected;
-      tabs[key].setAttribute("aria-selected", String(selected));
-      tabs[key].tabIndex = selected ? 0 : -1;
-    }
-    if (name === "glossary") void loadGlossaryEntries();
-    if (name === "summary") {
-      if (session) void runSummaries(session);
-      else if (!summaryContent.childElementCount) showSummaryMessage("请先打开一篇英文网页文章。");
-    }
-  }
-
-  function showSummaryMessage(message) {
-    const note = document.createElement("p");
-    note.className = "yidu-summary-note";
-    note.textContent = message;
-    summaryContent.replaceChildren(note);
-  }
-
-  function renderSummaryOutline(current) {
-    const modules = groupArticleModules(current.article);
-    current.summaryModules = modules;
-    summaryContent.replaceChildren();
-    const title = document.createElement("h1");
-    title.className = "yidu-summary-title";
-    title.textContent = current.article.title;
-    const originalTitle = document.createElement("p");
-    originalTitle.className = "yidu-summary-article-original";
-    originalTitle.textContent = current.article.title;
-    originalTitle.hidden = true;
-    current.summaryTitle = title;
-    current.summaryOriginalTitle = originalTitle;
-    const intro = document.createElement("p");
-    intro.className = "yidu-view-intro";
-    intro.textContent = modules.length + " 个大模块 · 按原文章节组织";
-    summaryContent.append(title, originalTitle, intro);
-    if (!modules.length) {
-      intro.textContent = "文章中没有可生成导读的正文。";
-      return;
-    }
-    for (const [index, module] of modules.entries()) {
-      const section = document.createElement("section");
-      section.className = "yidu-summary-module";
-      section.dataset.moduleId = module.id;
-      section.tabIndex = 0;
-      section.setAttribute("role", "link");
-      section.setAttribute("aria-label", "定位英文原文：" + module.title);
-      section.addEventListener("click", (event) => {
-        if (!event.target.closest("button, a, input, textarea, select")) void locateSourceModule(current, module);
-      });
-      section.addEventListener("keydown", (event) => {
-        if (event.key !== "Enter" && event.key !== " ") return;
-        event.preventDefault();
-        void locateSourceModule(current, module);
-      });
-      const number = document.createElement("span");
-      number.className = "yidu-summary-number";
-      number.textContent = String(index + 1).padStart(2, "0");
-      const details = document.createElement("div");
-      details.className = "yidu-summary-details";
-      const heading = document.createElement("h2");
-      heading.textContent = module.title;
-      const body = document.createElement("div");
-      body.className = "yidu-summary-body";
-      const pending = document.createElement("p");
-      pending.className = "yidu-summary-pending";
-      pending.textContent = "等待导读…";
-      body.append(pending);
-      details.append(heading, body);
-      section.append(number, details);
-      summaryContent.append(section);
-    }
-    if (activeView === "summary") void runSummaries(current);
-  }
-
-  async function locateSourceModule(current, module) {
-    if (current.stopped) return;
+  async function announcePanelOpen() {
     try {
-      await chrome.tabs.sendMessage(current.tabId, {
-        type: "YIDU_SCROLL_TO_SEGMENT",
-        payload: { segmentId: module.startId }
-      });
+      const tab = await chrome.tabs.getCurrent();
+      if (tab?.id != null) panelPort = chrome.runtime.connect({ name: `yidu-panel-open:${tab.id}` });
     } catch {
-      // 页面连接失效时，保留导读内容供用户继续阅读。
-    }
-  }
-  function updateSummaryArticleTitle(current, segment) {
-    if (segment?.kind !== "h1" || !current.summaryTitle || !current.summaryOriginalTitle) return;
-    const translated = current.rows.get(segment.id)?.textContent?.trim();
-    if (!translated || translated === current.article.title) return;
-    current.summaryTitle.textContent = translated;
-    current.summaryOriginalTitle.hidden = false;
-  }
-  function summaryBody(module) {
-    return [...summaryContent.querySelectorAll(".yidu-summary-module")]
-      .find((section) => section.dataset.moduleId === module.id)
-      ?.querySelector(".yidu-summary-body");
-  }
-
-  async function runSummaries(current) {
-    if (current.stopped || current.summaryRunning || activeView !== "summary") return;
-    current.summaryRunning = true;
-    try {
-      for (const module of current.summaryModules) {
-        if (current.stopped || activeView !== "summary") break;
-        if (current.summaryResults.has(module.id) || current.summaryFailed.has(module.id)) continue;
-        const outcome = await summarizeOne(current, module);
-        if (outcome?.code === "SETUP_REQUIRED") break;
-      }
-    } finally {
-      current.summaryRunning = false;
-    }
-  }
-
-  async function summarizeOne(current, module) {
-    if (current.stopped || current.summaryInFlight.has(module.id)) return null;
-    const body = summaryBody(module);
-    if (!body) return null;
-    current.summaryInFlight.add(module.id);
-    body.setAttribute("aria-busy", "true");
-    const pending = document.createElement("p");
-    pending.className = "yidu-summary-pending";
-    pending.textContent = "正在生成导读…";
-    body.replaceChildren(pending);
-    let outcome;
-    try {
-      outcome = await chrome.runtime.sendMessage({
-        type: "YIDU_SUMMARIZE_MODULE",
-        payload: { url: current.article.url, title: current.article.title, module }
-      });
-      if (current.stopped) return outcome;
-      if (!outcome?.ok) throw new Error(outcome?.message || "导读生成失败，请重试。");
-      current.summaryResults.set(module.id, outcome.result);
-      const details = body.parentElement;
-      details.querySelector("h2").textContent = outcome.result.title;
-      const original = document.createElement("p");
-      original.className = "yidu-summary-original";
-      original.textContent = module.title;
-      details.querySelector(".yidu-summary-original")?.remove();
-      details.insertBefore(original, body);
-      const summary = document.createElement("p");
-      summary.className = "yidu-summary-overview";
-      summary.textContent = outcome.result.summary;
-      body.replaceChildren(summary);
-    } catch (error) {
-      if (!current.stopped) {
-        current.summaryFailed.add(module.id);
-        const message = document.createElement("p");
-        message.className = "yidu-summary-failure";
-        message.textContent = error?.message || "导读生成失败，请重试。";
-        const actions = document.createElement("div");
-        actions.className = "yidu-actions";
-        if (outcome?.code === "SETUP_REQUIRED") {
-          const settings = document.createElement("button");
-          settings.className = "yidu-action secondary";
-          settings.type = "button";
-          settings.textContent = "打开设置";
-          settings.addEventListener("click", () => chrome.runtime.sendMessage({ type: "YIDU_OPEN_OPTIONS" }));
-          actions.append(settings);
-        }
-        const retry = document.createElement("button");
-        retry.className = "yidu-action secondary";
-        retry.type = "button";
-        retry.textContent = "重试";
-        retry.addEventListener("click", () => {
-          current.summaryFailed.delete(module.id);
-          void summarizeOne(current, module).then((result) => {
-            if (result?.ok) void runSummaries(current);
-          });
-        });
-        actions.append(retry);
-        body.replaceChildren(message, actions);
-      }
-    } finally {
-      current.summaryInFlight.delete(module.id);
-      body.removeAttribute("aria-busy");
-    }
-    return outcome;
-  }
-
-  function resetGlossaryForm() {
-    editingSource = "";
-    glossaryForm.reset();
-    glossarySource.readOnly = false;
-    glossaryCancel.hidden = true;
-    glossaryForm.querySelector('button[type="submit"]').textContent = "保存译法";
-  }
-
-  async function saveGlossaryFromForm(event) {
-    event.preventDefault();
-    const button = glossaryForm.querySelector('button[type="submit"]');
-    button.disabled = true;
-    glossaryStatus.textContent = "正在保存…";
-    try {
-      const result = await chrome.runtime.sendMessage({
-        type: "YIDU_GLOSSARY_UPSERT",
-        payload: { source: editingSource || glossarySource.value, target: glossaryTarget.value }
-      });
-      if (!result?.ok) throw new Error(result?.message || "保存失败");
-      resetGlossaryForm();
-      await loadGlossaryEntries();
-      glossaryStatus.textContent = "固定译法已保存。";
-    } catch (error) {
-      glossaryStatus.textContent = error?.message || "保存失败，请重试。";
-    } finally {
-      button.disabled = false;
-    }
-  }
-
-  async function loadGlossaryEntries() {
-    try {
-      const result = await chrome.runtime.sendMessage({ type: "YIDU_GLOSSARY_GET" });
-      if (!result?.ok) throw new Error(result?.message || "读取失败");
-      glossaryList.replaceChildren();
-      const entries = (result.entries || []).sort((left, right) =>
-        left.source.toLocaleLowerCase().localeCompare(right.source.toLocaleLowerCase()));
-      if (!entries.length) {
-        const empty = document.createElement("p");
-        empty.className = "yidu-glossary-empty";
-        empty.textContent = "还没有固定译法。可在这里添加，也可在原网页选词后保存。";
-        glossaryList.append(empty);
-      }
-      for (const entry of entries) {
-        const row = document.createElement("div");
-        row.className = "yidu-glossary-entry";
-        const words = document.createElement("div");
-        words.className = "yidu-glossary-words";
-        const source = document.createElement("strong");
-        source.textContent = entry.source;
-        const arrow = document.createElement("span");
-        arrow.textContent = "→";
-        const target = document.createElement("span");
-        target.textContent = entry.target;
-        words.append(source, arrow, target);
-        const actions = document.createElement("div");
-        actions.className = "yidu-glossary-actions";
-        const edit = document.createElement("button");
-        edit.type = "button";
-        edit.textContent = "编辑";
-        edit.addEventListener("click", () => {
-          editingSource = entry.source;
-          glossarySource.value = entry.source;
-          glossarySource.readOnly = true;
-          glossaryTarget.value = entry.target;
-          glossaryCancel.hidden = false;
-          glossaryForm.querySelector('button[type="submit"]').textContent = "更新译法";
-          glossaryTarget.focus();
-        });
-        const remove = document.createElement("button");
-        remove.type = "button";
-        remove.textContent = "删除";
-        remove.addEventListener("click", async () => {
-          remove.disabled = true;
-          const result = await chrome.runtime.sendMessage({
-            type: "YIDU_GLOSSARY_DELETE",
-            payload: { source: entry.source }
-          }).catch(() => null);
-          if (result?.ok) {
-            if (editingSource.toLocaleLowerCase() === entry.source.toLocaleLowerCase()) resetGlossaryForm();
-            await loadGlossaryEntries();
-            glossaryStatus.textContent = "固定译法已删除。";
-          } else {
-            glossaryStatus.textContent = result?.message || "删除失败，请重试。";
-            remove.disabled = false;
-          }
-        });
-        actions.append(edit, remove);
-        row.append(words, actions);
-        glossaryList.append(row);
-      }
-    } catch (error) {
-      glossaryStatus.textContent = error?.message || "读取固定译法失败。";
-    }
-  }
-
-  function scheduleReload() {
-    window.clearTimeout(reloadTimer);
-    reloadTimer = window.setTimeout(() => void loadActiveArticle(), 120);
-  }
-
-  function handleSourceScroll(payload, tabId) {
-    const current = session;
-    if (!current || current.stopped || tabId !== current.tabId) return;
-    const row = current.rows.get(String(payload?.segmentId || ""));
-    if (!row || activeView !== "translation") return;
-    const index = current.article.segments.findIndex((segment) => segment.id === row.dataset.segmentId);
-    current.article.segments.slice(index, index + BATCH_SIZE).forEach((segment) => enqueue(current, segment));
-    requestAnimationFrame(() => {
-      if (current.stopped) return;
-      const rect = row.getBoundingClientRect();
-      const ratio = Math.max(0, Math.min(1, Number(payload?.ratio || 0)));
-      const target = window.scrollY + rect.top + rect.height * ratio - window.innerHeight * 0.35;
-      const maxScroll = Math.max(0, document.documentElement.scrollHeight - window.innerHeight);
-      window.scrollTo(0, Math.max(0, Math.min(maxScroll, target)));
-    });
-  }
-  function handleSourceSelection(payload, tabId) {
-    const current = session;
-    if (!current || current.stopped || tabId !== current.tabId) return;
-    const ids = new Set(
-      (Array.isArray(payload?.segmentIds) ? payload.segmentIds : [])
-        .map(String)
-        .filter((id) => current.segmentsById.get(id)?.kind !== "skipped" && current.rows.has(id))
-    );
-    const previous = current.selectedSegmentIds;
-    if (ids.size === previous.size && [...ids].every((id) => previous.has(id))) return;
-    for (const id of previous) current.rows.get(id)?.classList.remove("yidu-source-selected");
-    for (const id of ids) current.rows.get(id)?.classList.add("yidu-source-selected");
-    current.selectedSegmentIds = ids;
-    const first = current.rows.get(ids.values().next().value);
-    if (first && activeView === "translation") {
-      requestAnimationFrame(() => {
-        if (!current.stopped && current.selectedSegmentIds.has(first.dataset.segmentId)) {
-          first.scrollIntoView({ block: "center", behavior: "auto" });
-        }
-      });
-    }
-  }
-  function handleGlossaryChanged(payload) {
-    if (activeView === "glossary") void loadGlossaryEntries();
-    const current = session;
-    const source = String(payload?.source || "").trim();
-    if (!current || current.stopped || !source) return;
-    for (const key of Object.keys(current.glossary)) {
-      if (key.toLocaleLowerCase() === source.toLocaleLowerCase()) delete current.glossary[key];
-    }
-    if (payload?.target) current.glossary[source] = String(payload.target);
-    current.glossaryEpoch += 1;
-    if (current.failed) {
-      current.failed = false;
-      document.querySelector(".yidu-error")?.remove();
-      current.failedSegments.splice(0).forEach((segment) => enqueue(current, segment));
+      // 无法确认所属标签页时，划词浮窗保持关闭。
     }
-    for (const segment of current.article.segments) {
-      if (segment.kind === "skipped" || !containsTerm(segment.text, source)) continue;
-      if (current.completed.delete(segment.id)) {
-        const row = current.rows.get(segment.id);
-        row?.classList.add("yidu-refreshing");
-        row?.setAttribute("aria-busy", "true");
-        enqueue(current, segment);
-      } else if (current.selectedSegmentIds.has(segment.id)) {
-        enqueue(current, segment);
-      }
-    }
-  }
-
-  async function loadActiveArticle() {
-    stopSession();
-    setStatus("正在读取文章…");
-    content.setAttribute("aria-busy", "true");
-    content.replaceChildren();
-    summaryContent.replaceChildren();
-    try {
-      const tab = await findArticleTab();
-      if (!tab?.id) throw new Error("请先打开一篇英文网页文章。");
-      const response = await getArticleFromTab(tab.id);
-      if (!response?.ok || !response.article?.segments?.length) {
-        throw new Error(response?.message || "没有识别到可翻译的英文文章正文。");
-      }
-      startSession(response.article, tab.id);
-    } catch (error) {
-      const message = error?.message || "无法读取当前页面。";
-      showEmpty(message, true);
-      showSummaryMessage(message);
-    }
-  }
-
-  async function findArticleTab() {
-    const tabs = await chrome.tabs.query({ currentWindow: true });
-    return tabs
-      .filter((tab) => /^https?:/i.test(tab.url || ""))
-      .sort((left, right) => Number(right.active) - Number(left.active) || Number(right.lastAccessed || 0) - Number(left.lastAccessed || 0))[0];
-  }
-
-  async function getArticleFromTab(tabId) {
-    await waitForTabReady(tabId);
-    try {
-      return await chrome.tabs.sendMessage(tabId, { type: "YIDU_GET_ARTICLE" });
-    } catch {
-      // The receiver disappears when an unpacked extension is reloaded while the
-      // article tab stays open. Ask the service worker to inject it again.
-    }
-
-    const prepared = await chrome.runtime.sendMessage({
-      type: "YIDU_PREPARE_TAB",
-      payload: { tabId }
-    });
-    if (!prepared?.ok) {
-      return prepared || { ok: false, message: "无法读取当前页面，请刷新页面后重试。" };
-    }
-
-    for (let attempt = 0; attempt < 3; attempt += 1) {
-      try {
-        return await chrome.tabs.sendMessage(tabId, { type: "YIDU_GET_ARTICLE" });
-      } catch {
-        await delay(180);
-      }
-    }
-    return { ok: false, message: "页面连接失败，请刷新文章页面后重试。" };
-  }
-
-  async function waitForTabReady(tabId) {
-    for (let attempt = 0; attempt < 12; attempt += 1) {
-      const tab = await chrome.tabs.get(tabId);
-      if (tab.status === "complete") return;
-      await delay(150);
-    }
-  }
-
-  function delay(milliseconds) {
-    return new Promise((resolve) => window.setTimeout(resolve, milliseconds));
-  }
-
-  function startSession(article, tabId) {
-    const next = {
-      article,
-      tabId,
-      rows: new Map(),
-      segmentsById: new Map(article.segments.map((segment) => [segment.id, segment])),
-      translations: new Map(),
-      completed: new Set(),
-      queued: new Set(),
-      queue: [],
-      glossary: {},
-      observer: null,
-      working: false,
-      stopped: false,
-      failed: false,
-      failedSegments: [],
-      cachedCount: 0,
-      summaryModules: [],
-      summaryResults: new Map(),
-      summaryFailed: new Set(),
-      summaryInFlight: new Set(),
-      summaryRunning: false,
-      summaryTitle: null,
-      summaryOriginalTitle: null,
-      selectedSegmentIds: new Set(),
-      glossaryEpoch: 0
-    };
-    session = next;
-    renderArticle(next);
-    renderSummaryOutline(next);
-    void restoreCache(next).then(() => {
-      if (next.stopped) return;
-      startViewportTranslation(next);
-      void chrome.tabs.sendMessage(next.tabId, { type: "YIDU_REQUEST_SCROLL_SYNC" }).catch(() => undefined);
-      void chrome.tabs.sendMessage(next.tabId, { type: "YIDU_REQUEST_SELECTION_SYNC" }).catch(() => undefined);
-    });
-  }
-
-  function renderArticle(current) {
-    content.replaceChildren();
-    let list = null;
-    let listKind = "";
-    for (const segment of current.article.segments) {
-      if (segment.kind === "cell") continue;
-      const isListItem = segment.kind === "ul-item" || segment.kind === "ol-item";
-      let element;
-      if (isListItem) {
-        if (!list || listKind !== segment.kind) {
-          list = document.createElement(segment.kind === "ol-item" ? "ol" : "ul");
-          list.className = "yidu-list";
-          content.append(list);
-          listKind = segment.kind;
-        }
-        element = document.createElement("li");
-        list.append(element);
-      } else {
-        list = null;
-        listKind = "";
-        const tag = /^h[1-6]$/.test(segment.kind) ? segment.kind : segment.kind === "blockquote" ? "blockquote" : "p";
-        element = document.createElement(tag);
-        content.append(element);
-      }
-      element.className = `yidu-segment yidu-${segment.kind} yidu-pending`;
-      if (segment.kind === "skipped") {
-        element.textContent = segment.text;
-        element.classList.remove("yidu-pending");
-        element.removeAttribute("aria-busy");
-        current.completed.add(segment.id);
-      }
-      element.dataset.segmentId = segment.id;
-      if (segment.kind !== "skipped") element.setAttribute("aria-busy", "true");
-      current.rows.set(segment.id, element);
-    }
-    content.setAttribute("aria-busy", "false");
-  }
-
-  async function restoreCache(current) {
-    try {
-      const result = await chrome.runtime.sendMessage({
-        type: "YIDU_CACHE_GET",
-        payload: { url: current.article.url, segments: current.article.segments }
-      });
-      if (!result?.ok || current.stopped) return;
-      for (const item of result.items || []) applyTranslation(current, item, true);
-    } catch {
-      // 缓存不可用时继续翻译。
-    }
-  }
-
-  function startViewportTranslation(current) {
-    current.article.segments.slice(0, BATCH_SIZE).forEach((segment) => enqueue(current, segment));
-    current.article.segments.filter((segment) => segment.kind === "cell").forEach((segment) => enqueue(current, segment));
-    if (!("IntersectionObserver" in window)) {
-      current.article.segments.forEach((segment) => enqueue(current, segment));
-      return;
-    }
-    current.observer = new IntersectionObserver((entries) => {
-      entries.filter((entry) => entry.isIntersecting).forEach((entry) => {
-        const segment = current.segmentsById.get(entry.target.dataset.segmentId);
-        if (segment) enqueue(current, segment);
-        current.observer?.unobserve(entry.target);
-      });
-    }, { rootMargin: VIEWPORT_MARGIN, threshold: 0 });
-    for (const row of current.rows.values()) {
-      if (!current.completed.has(row.dataset.segmentId)) current.observer.observe(row);
-    }
-    updateProgress(current);
-  }
-
-  function enqueue(current, segment) {
-    if (current.stopped || current.failed || segment.kind === "skipped" || current.completed.has(segment.id) || current.queued.has(segment.id)) return;
-    current.queue.push(segment);
-    current.queued.add(segment.id);
-    queueMicrotask(() => void processQueue(current));
-  }
-
-  async function processQueue(current) {
-    if (current.working || current.stopped || current.failed) return;
-    current.working = true;
-    try {
-      while (current.queue.length && !current.stopped && !current.failed) {
-        const segments = current.queue.splice(0, BATCH_SIZE);
-        segments.forEach((segment) => current.queued.delete(segment.id));
-        current.failedSegments = segments;
-        updateProgress(current, segments.length);
-        const epoch = current.glossaryEpoch;
-        const result = await chrome.runtime.sendMessage({
-          type: "YIDU_TRANSLATE_BATCH",
-          payload: { title: current.article.title, segments, glossary: current.glossary }
-        });
-        if (!result?.ok) throw Object.assign(new Error(result?.message || "翻译失败"), { code: result?.code });
-        if (current.stopped) return;
-        if (epoch !== current.glossaryEpoch) {
-          segments.forEach((segment) => enqueue(current, segment));
-          continue;
-        }
-        for (const item of result.items) applyTranslation(current, item, false);
-        void chrome.runtime.sendMessage({
-          type: "YIDU_CACHE_PUT",
-          payload: { url: current.article.url, segments, items: result.items, glossarySnapshot: result.glossarySnapshot }
-        }).catch(() => undefined);
-        current.failedSegments = [];
-      }
-    } catch (error) {
-      current.failed = true;
-      showError(current, error?.message || "翻译失败，请稍后重试。", error?.code === "SETUP_REQUIRED");
-    } finally {
-      current.working = false;
-      updateProgress(current);
-    }
-  }
-
-  function applyTranslation(current, item, fromCache) {
-    if (current.completed.has(item.id)) return;
-    const segment = current.segmentsById.get(item.id);
-    if (!segment) return;
-    current.translations.set(item.id, item);
-    for (const term of item.terms || []) current.glossary[term.source] = term.target;
-    current.completed.add(item.id);
-    if (fromCache) current.cachedCount += 1;
-    const translatedRow = current.rows.get(item.id);
-    if (translatedRow) current.observer?.unobserve(translatedRow);
-    renderTranslation(current, item.id, item);
-    if (segment.kind === "cell") {
-      void chrome.tabs.sendMessage(current.tabId, {
-        type: "YIDU_RENDER_CELLS",
-        payload: { items: [{ id: item.id, translation: item.translation }] }
-      }).catch(() => undefined);
-    }
-    updateSummaryArticleTitle(current, segment);
-    updateProgress(current);
-  }
-
+  }
+
+  function selectView(name) {
+    activeView = name;
+    for (const [key, view] of Object.entries(views)) {
+      const selected = key === name;
+      view.hidden = !selected;
+      tabs[key].setAttribute("aria-selected", String(selected));
+      tabs[key].tabIndex = selected ? 0 : -1;
+    }
+    if (name === "glossary") void loadGlossaryEntries();
+    if (name === "summary") {
+      if (session) void runSummaries(session);
+      else if (!summaryContent.childElementCount) showSummaryMessage("请先打开一篇英文网页文章。");
+    }
+  }
+
+  function showSummaryMessage(message) {
+    const note = document.createElement("p");
+    note.className = "yidu-summary-note";
+    note.textContent = message;
+    summaryContent.replaceChildren(note);
+  }
+
+  function renderSummaryOutline(current) {
+    const modules = groupArticleModules(current.article);
+    current.summaryModules = modules;
+    summaryContent.replaceChildren();
+    const title = document.createElement("h1");
+    title.className = "yidu-summary-title";
+    title.textContent = current.article.title;
+    const originalTitle = document.createElement("p");
+    originalTitle.className = "yidu-summary-article-original";
+    originalTitle.textContent = current.article.title;
+    originalTitle.hidden = true;
+    current.summaryTitle = title;
+    current.summaryOriginalTitle = originalTitle;
+    const intro = document.createElement("p");
+    intro.className = "yidu-view-intro";
+    intro.textContent = modules.length + " 个大模块 · 按原文章节组织";
+    summaryContent.append(title, originalTitle, intro);
+    if (!modules.length) {
+      intro.textContent = "文章中没有可生成导读的正文。";
+      return;
+    }
+    for (const [index, module] of modules.entries()) {
+      const section = document.createElement("section");
+      section.className = "yidu-summary-module";
+      section.dataset.moduleId = module.id;
+      section.tabIndex = 0;
+      section.setAttribute("role", "link");
+      section.setAttribute("aria-label", "定位英文原文：" + module.title);
+      section.addEventListener("click", (event) => {
+        if (!event.target.closest("button, a, input, textarea, select")) void locateSourceModule(current, module);
+      });
+      section.addEventListener("keydown", (event) => {
+        if (event.key !== "Enter" && event.key !== " ") return;
+        event.preventDefault();
+        void locateSourceModule(current, module);
+      });
+      const number = document.createElement("span");
+      number.className = "yidu-summary-number";
+      number.textContent = String(index + 1).padStart(2, "0");
+      const details = document.createElement("div");
+      details.className = "yidu-summary-details";
+      const heading = document.createElement("h2");
+      heading.textContent = module.title;
+      const body = document.createElement("div");
+      body.className = "yidu-summary-body";
+      const pending = document.createElement("p");
+      pending.className = "yidu-summary-pending";
+      pending.textContent = "等待导读…";
+      body.append(pending);
+      details.append(heading, body);
+      section.append(number, details);
+      summaryContent.append(section);
+    }
+    if (activeView === "summary") void runSummaries(current);
+  }
+
+  async function locateSourceModule(current, module) {
+    if (current.stopped) return;
+    try {
+      await chrome.tabs.sendMessage(current.tabId, {
+        type: "YIDU_SCROLL_TO_SEGMENT",
+        payload: { segmentId: module.startId }
+      });
+    } catch {
+      // 页面连接失效时，保留导读内容供用户继续阅读。
+    }
+  }
+  function updateSummaryArticleTitle(current, segment) {
+    if (segment?.kind !== "h1" || !current.summaryTitle || !current.summaryOriginalTitle) return;
+    const translated = current.rows.get(segment.id)?.textContent?.trim();
+    if (!translated || translated === current.article.title) return;
+    current.summaryTitle.textContent = translated;
+    current.summaryOriginalTitle.hidden = false;
+  }
+  function summaryBody(module) {
+    return [...summaryContent.querySelectorAll(".yidu-summary-module")]
+      .find((section) => section.dataset.moduleId === module.id)
+      ?.querySelector(".yidu-summary-body");
+  }
+
+  async function runSummaries(current) {
+    if (current.stopped || current.summaryRunning || activeView !== "summary") return;
+    current.summaryRunning = true;
+    try {
+      for (const module of current.summaryModules) {
+        if (current.stopped || activeView !== "summary") break;
+        if (current.summaryResults.has(module.id) || current.summaryFailed.has(module.id)) continue;
+        const outcome = await summarizeOne(current, module);
+        if (outcome?.code === "SETUP_REQUIRED") break;
+      }
+    } finally {
+      current.summaryRunning = false;
+    }
+  }
+
+  async function summarizeOne(current, module) {
+    if (current.stopped || current.summaryInFlight.has(module.id)) return null;
+    const body = summaryBody(module);
+    if (!body) return null;
+    current.summaryInFlight.add(module.id);
+    body.setAttribute("aria-busy", "true");
+    const pending = document.createElement("p");
+    pending.className = "yidu-summary-pending";
+    pending.textContent = "正在生成导读…";
+    body.replaceChildren(pending);
+    let outcome;
+    try {
+      outcome = await chrome.runtime.sendMessage({
+        type: "YIDU_SUMMARIZE_MODULE",
+        payload: { url: current.article.url, title: current.article.title, module }
+      });
+      if (current.stopped) return outcome;
+      if (!outcome?.ok) throw new Error(outcome?.message || "导读生成失败，请重试。");
+      current.summaryResults.set(module.id, outcome.result);
+      const details = body.parentElement;
+      details.querySelector("h2").textContent = outcome.result.title;
+      const original = document.createElement("p");
+      original.className = "yidu-summary-original";
+      original.textContent = module.title;
+      details.querySelector(".yidu-summary-original")?.remove();
+      details.insertBefore(original, body);
+      const summary = document.createElement("p");
+      summary.className = "yidu-summary-overview";
+      summary.textContent = outcome.result.summary;
+      body.replaceChildren(summary);
+    } catch (error) {
+      if (!current.stopped) {
+        current.summaryFailed.add(module.id);
+        const message = document.createElement("p");
+        message.className = "yidu-summary-failure";
+        message.textContent = error?.message || "导读生成失败，请重试。";
+        const actions = document.createElement("div");
+        actions.className = "yidu-actions";
+        if (outcome?.code === "SETUP_REQUIRED") {
+          const settings = document.createElement("button");
+          settings.className = "yidu-action secondary";
+          settings.type = "button";
+          settings.textContent = "打开设置";
+          settings.addEventListener("click", () => chrome.runtime.sendMessage({ type: "YIDU_OPEN_OPTIONS" }));
+          actions.append(settings);
+        }
+        const retry = document.createElement("button");
+        retry.className = "yidu-action secondary";
+        retry.type = "button";
+        retry.textContent = "重试";
+        retry.addEventListener("click", () => {
+          current.summaryFailed.delete(module.id);
+          void summarizeOne(current, module).then((result) => {
+            if (result?.ok) void runSummaries(current);
+          });
+        });
+        actions.append(retry);
+        body.replaceChildren(message, actions);
+      }
+    } finally {
+      current.summaryInFlight.delete(module.id);
+      body.removeAttribute("aria-busy");
+    }
+    return outcome;
+  }
+
+  function resetGlossaryForm() {
+    editingSource = "";
+    glossaryForm.reset();
+    glossarySource.readOnly = false;
+    glossaryCancel.hidden = true;
+    glossaryForm.querySelector('button[type="submit"]').textContent = "保存译法";
+  }
+
+  async function saveGlossaryFromForm(event) {
+    event.preventDefault();
+    const button = glossaryForm.querySelector('button[type="submit"]');
+    button.disabled = true;
+    glossaryStatus.textContent = "正在保存…";
+    try {
+      const result = await chrome.runtime.sendMessage({
+        type: "YIDU_GLOSSARY_UPSERT",
+        payload: { source: editingSource || glossarySource.value, target: glossaryTarget.value }
+      });
+      if (!result?.ok) throw new Error(result?.message || "保存失败");
+      resetGlossaryForm();
+      await loadGlossaryEntries();
+      glossaryStatus.textContent = "固定译法已保存。";
+    } catch (error) {
+      glossaryStatus.textContent = error?.message || "保存失败，请重试。";
+    } finally {
+      button.disabled = false;
+    }
+  }
+
+  async function loadGlossaryEntries() {
+    try {
+      const result = await chrome.runtime.sendMessage({ type: "YIDU_GLOSSARY_GET" });
+      if (!result?.ok) throw new Error(result?.message || "读取失败");
+      glossaryList.replaceChildren();
+      const entries = (result.entries || []).sort((left, right) =>
+        left.source.toLocaleLowerCase().localeCompare(right.source.toLocaleLowerCase()));
+      if (!entries.length) {
+        const empty = document.createElement("p");
+        empty.className = "yidu-glossary-empty";
+        empty.textContent = "还没有固定译法。可在这里添加，也可在原网页选词后保存。";
+        glossaryList.append(empty);
+      }
+      for (const entry of entries) {
+        const row = document.createElement("div");
+        row.className = "yidu-glossary-entry";
+        const words = document.createElement("div");
+        words.className = "yidu-glossary-words";
+        const source = document.createElement("strong");
+        source.textContent = entry.source;
+        const arrow = document.createElement("span");
+        arrow.textContent = "→";
+        const target = document.createElement("span");
+        target.textContent = entry.target;
+        words.append(source, arrow, target);
+        const actions = document.createElement("div");
+        actions.className = "yidu-glossary-actions";
+        const edit = document.createElement("button");
+        edit.type = "button";
+        edit.textContent = "编辑";
+        edit.addEventListener("click", () => {
+          editingSource = entry.source;
+          glossarySource.value = entry.source;
+          glossarySource.readOnly = true;
+          glossaryTarget.value = entry.target;
+          glossaryCancel.hidden = false;
+          glossaryForm.querySelector('button[type="submit"]').textContent = "更新译法";
+          glossaryTarget.focus();
+        });
+        const remove = document.createElement("button");
+        remove.type = "button";
+        remove.textContent = "删除";
+        remove.addEventListener("click", async () => {
+          remove.disabled = true;
+          const result = await chrome.runtime.sendMessage({
+            type: "YIDU_GLOSSARY_DELETE",
+            payload: { source: entry.source }
+          }).catch(() => null);
+          if (result?.ok) {
+            if (editingSource.toLocaleLowerCase() === entry.source.toLocaleLowerCase()) resetGlossaryForm();
+            await loadGlossaryEntries();
+            glossaryStatus.textContent = "固定译法已删除。";
+          } else {
+            glossaryStatus.textContent = result?.message || "删除失败，请重试。";
+            remove.disabled = false;
+          }
+        });
+        actions.append(edit, remove);
+        row.append(words, actions);
+        glossaryList.append(row);
+      }
+    } catch (error) {
+      glossaryStatus.textContent = error?.message || "读取固定译法失败。";
+    }
+  }
+
+  function scheduleReload() {
+    window.clearTimeout(reloadTimer);
+    reloadTimer = window.setTimeout(() => void loadActiveArticle(), 120);
+  }
+
+  function handleSourceScroll(payload, tabId) {
+    const current = session;
+    if (!current || current.stopped || tabId !== current.tabId) return;
+    const row = current.rows.get(String(payload?.segmentId || ""));
+    if (!row || activeView !== "translation") return;
+    const index = current.article.segments.findIndex((segment) => segment.id === row.dataset.segmentId);
+    current.article.segments.slice(index, index + BATCH_SIZE).forEach((segment) => enqueue(current, segment));
+    requestAnimationFrame(() => {
+      if (current.stopped) return;
+      const rect = row.getBoundingClientRect();
+      const ratio = Math.max(0, Math.min(1, Number(payload?.ratio || 0)));
+      const target = window.scrollY + rect.top + rect.height * ratio - window.innerHeight * 0.35;
+      const maxScroll = Math.max(0, document.documentElement.scrollHeight - window.innerHeight);
+      window.scrollTo(0, Math.max(0, Math.min(maxScroll, target)));
+    });
+  }
+  function handleSourceSelection(payload, tabId) {
+    const current = session;
+    if (!current || current.stopped || tabId !== current.tabId) return;
+    const ids = new Set(
+      (Array.isArray(payload?.segmentIds) ? payload.segmentIds : [])
+        .map(String)
+        .filter((id) => current.segmentsById.get(id)?.kind !== "skipped" && current.rows.has(id))
+    );
+    const previous = current.selectedSegmentIds;
+    if (ids.size === previous.size && [...ids].every((id) => previous.has(id))) return;
+    for (const id of previous) current.rows.get(id)?.classList.remove("yidu-source-selected");
+    for (const id of ids) current.rows.get(id)?.classList.add("yidu-source-selected");
+    current.selectedSegmentIds = ids;
+    const first = current.rows.get(ids.values().next().value);
+    if (first && activeView === "translation") {
+      requestAnimationFrame(() => {
+        if (!current.stopped && current.selectedSegmentIds.has(first.dataset.segmentId)) {
+          first.scrollIntoView({ block: "center", behavior: "auto" });
+        }
+      });
+    }
+  }
+  function handleGlossaryChanged(payload) {
+    if (activeView === "glossary") void loadGlossaryEntries();
+    const current = session;
+    const source = String(payload?.source || "").trim();
+    if (!current || current.stopped || !source) return;
+    for (const key of Object.keys(current.glossary)) {
+      if (key.toLocaleLowerCase() === source.toLocaleLowerCase()) delete current.glossary[key];
+    }
+    if (payload?.target) current.glossary[source] = String(payload.target);
+    current.glossaryEpoch += 1;
+    if (current.failed) {
+      current.failed = false;
+      document.querySelector(".yidu-error")?.remove();
+      current.failedSegments.splice(0).forEach((segment) => enqueue(current, segment));
+    }
+    for (const segment of current.article.segments) {
+      if (segment.kind === "skipped" || !containsTerm(segment.text, source)) continue;
+      if (current.completed.delete(segment.id)) {
+        const row = current.rows.get(segment.id);
+        row?.classList.add("yidu-refreshing");
+        row?.setAttribute("aria-busy", "true");
+        enqueue(current, segment);
+      } else if (current.selectedSegmentIds.has(segment.id)) {
+        enqueue(current, segment);
+      }
+    }
+  }
+
+  async function loadActiveArticle() {
+    stopSession();
+    setStatus("正在读取文章…");
+    content.setAttribute("aria-busy", "true");
+    content.replaceChildren();
+    summaryContent.replaceChildren();
+    try {
+      const tab = await findArticleTab();
+      if (!tab?.id) throw new Error("请先打开一篇英文网页文章。");
+      const response = await getArticleFromTab(tab.id);
+      if (!response?.ok || !response.article?.segments?.length) {
+        throw new Error(response?.message || "没有识别到可翻译的英文文章正文。");
+      }
+      startSession(response.article, tab.id);
+    } catch (error) {
+      const message = error?.message || "无法读取当前页面。";
+      showEmpty(message, true);
+      showSummaryMessage(message);
+    }
+  }
+
+  async function findArticleTab() {
+    const tabs = await chrome.tabs.query({ currentWindow: true });
+    return tabs
+      .filter((tab) => /^https?:/i.test(tab.url || ""))
+      .sort((left, right) => Number(right.active) - Number(left.active) || Number(right.lastAccessed || 0) - Number(left.lastAccessed || 0))[0];
+  }
+
+  async function getArticleFromTab(tabId) {
+    await waitForTabReady(tabId);
+    try {
+      return await chrome.tabs.sendMessage(tabId, { type: "YIDU_GET_ARTICLE" });
+    } catch {
+      // The receiver disappears when an unpacked extension is reloaded while the
+      // article tab stays open. Ask the service worker to inject it again.
+    }
+
+    const prepared = await chrome.runtime.sendMessage({
+      type: "YIDU_PREPARE_TAB",
+      payload: { tabId }
+    });
+    if (!prepared?.ok) {
+      return prepared || { ok: false, message: "无法读取当前页面，请刷新页面后重试。" };
+    }
+
+    for (let attempt = 0; attempt < 3; attempt += 1) {
+      try {
+        return await chrome.tabs.sendMessage(tabId, { type: "YIDU_GET_ARTICLE" });
+      } catch {
+        await delay(180);
+      }
+    }
+    return { ok: false, message: "页面连接失败，请刷新文章页面后重试。" };
+  }
+
+  async function waitForTabReady(tabId) {
+    for (let attempt = 0; attempt < 12; attempt += 1) {
+      const tab = await chrome.tabs.get(tabId);
+      if (tab.status === "complete") return;
+      await delay(150);
+    }
+  }
+
+  function delay(milliseconds) {
+    return new Promise((resolve) => window.setTimeout(resolve, milliseconds));
+  }
+
+  function startSession(article, tabId) {
+    const next = {
+      article,
+      tabId,
+      rows: new Map(),
+      segmentsById: new Map(article.segments.map((segment) => [segment.id, segment])),
+      translations: new Map(),
+      completed: new Set(),
+      queued: new Set(),
+      queue: [],
+      glossary: {},
+      observer: null,
+      working: false,
+      stopped: false,
+      failed: false,
+      failedSegments: [],
+      cachedCount: 0,
+      summaryModules: [],
+      summaryResults: new Map(),
+      summaryFailed: new Set(),
+      summaryInFlight: new Set(),
+      summaryRunning: false,
+      summaryTitle: null,
+      summaryOriginalTitle: null,
+      selectedSegmentIds: new Set(),
+      glossaryEpoch: 0
+    };
+    session = next;
+    renderArticle(next);
+    renderSummaryOutline(next);
+    void restoreCache(next).then(() => {
+      if (next.stopped) return;
+      startViewportTranslation(next);
+      void chrome.tabs.sendMessage(next.tabId, { type: "YIDU_REQUEST_SCROLL_SYNC" }).catch(() => undefined);
+      void chrome.tabs.sendMessage(next.tabId, { type: "YIDU_REQUEST_SELECTION_SYNC" }).catch(() => undefined);
+    });
+  }
+
+  function renderArticle(current) {
+    content.replaceChildren();
+    let list = null;
+    let listKind = "";
+    for (const segment of current.article.segments) {
+      if (segment.kind === "cell") continue;
+      const isListItem = segment.kind === "ul-item" || segment.kind === "ol-item";
+      let element;
+      if (isListItem) {
+        if (!list || listKind !== segment.kind) {
+          list = document.createElement(segment.kind === "ol-item" ? "ol" : "ul");
+          list.className = "yidu-list";
+          content.append(list);
+          listKind = segment.kind;
+        }
+        element = document.createElement("li");
+        list.append(element);
+      } else {
+        list = null;
+        listKind = "";
+        const tag = /^h[1-6]$/.test(segment.kind) ? segment.kind : segment.kind === "blockquote" ? "blockquote" : "p";
+        element = document.createElement(tag);
+        content.append(element);
+      }
+      element.className = `yidu-segment yidu-${segment.kind} yidu-pending`;
+      if (segment.kind === "skipped") {
+        element.textContent = segment.text;
+        element.classList.remove("yidu-pending");
+        element.removeAttribute("aria-busy");
+        current.completed.add(segment.id);
+      }
+      element.dataset.segmentId = segment.id;
+      if (segment.kind !== "skipped") element.setAttribute("aria-busy", "true");
+      current.rows.set(segment.id, element);
+    }
+    content.setAttribute("aria-busy", "false");
+  }
+
+  async function restoreCache(current) {
+    try {
+      const result = await chrome.runtime.sendMessage({
+        type: "YIDU_CACHE_GET",
+        payload: { url: current.article.url, segments: current.article.segments }
+      });
+      if (!result?.ok || current.stopped) return;
+      for (const item of result.items || []) applyTranslation(current, item, true);
+    } catch {
+      // 缓存不可用时继续翻译。
+    }
+  }
+
+  function startViewportTranslation(current) {
+    current.article.segments.slice(0, BATCH_SIZE).forEach((segment) => enqueue(current, segment));
+    current.article.segments.filter((segment) => segment.kind === "cell").forEach((segment) => enqueue(current, segment));
+    if (!("IntersectionObserver" in window)) {
+      current.article.segments.forEach((segment) => enqueue(current, segment));
+      return;
+    }
+    current.observer = new IntersectionObserver((entries) => {
+      entries.filter((entry) => entry.isIntersecting).forEach((entry) => {
+        const segment = current.segmentsById.get(entry.target.dataset.segmentId);
+        if (segment) enqueue(current, segment);
+        current.observer?.unobserve(entry.target);
+      });
+    }, { rootMargin: VIEWPORT_MARGIN, threshold: 0 });
+    for (const row of current.rows.values()) {
+      if (!current.completed.has(row.dataset.segmentId)) current.observer.observe(row);
+    }
+    updateProgress(current);
+  }
+
+  function enqueue(current, segment) {
+    if (current.stopped || current.failed || segment.kind === "skipped" || current.completed.has(segment.id) || current.queued.has(segment.id)) return;
+    current.queue.push(segment);
+    current.queued.add(segment.id);
+    queueMicrotask(() => void processQueue(current));
+  }
+
+  async function processQueue(current) {
+    if (current.working || current.stopped || current.failed) return;
+    current.working = true;
+    try {
+      while (current.queue.length && !current.stopped && !current.failed) {
+        const segments = current.queue.splice(0, BATCH_SIZE);
+        segments.forEach((segment) => current.queued.delete(segment.id));
+        current.failedSegments = segments;
+        updateProgress(current, segments.length);
+        const epoch = current.glossaryEpoch;
+        const result = await chrome.runtime.sendMessage({
+          type: "YIDU_TRANSLATE_BATCH",
+          payload: { title: current.article.title, segments, glossary: current.glossary }
+        });
+        if (!result?.ok) throw Object.assign(new Error(result?.message || "翻译失败"), { code: result?.code });
+        if (current.stopped) return;
+        if (epoch !== current.glossaryEpoch) {
+          segments.forEach((segment) => enqueue(current, segment));
+          continue;
+        }
+        for (const item of result.items) applyTranslation(current, item, false);
+        void chrome.runtime.sendMessage({
+          type: "YIDU_CACHE_PUT",
+          payload: { url: current.article.url, segments, items: result.items, glossarySnapshot: result.glossarySnapshot }
+        }).catch(() => undefined);
+        current.failedSegments = [];
+      }
+    } catch (error) {
+      current.failed = true;
+      showError(current, error?.message || "翻译失败，请稍后重试。", error?.code === "SETUP_REQUIRED");
+    } finally {
+      current.working = false;
+      updateProgress(current);
+    }
+  }
+
+  function applyTranslation(current, item, fromCache) {
+    if (current.completed.has(item.id)) return;
+    const segment = current.segmentsById.get(item.id);
+    if (!segment) return;
+    current.translations.set(item.id, item);
+    for (const term of item.terms || []) current.glossary[term.source] = term.target;
+    current.completed.add(item.id);
+    if (fromCache) current.cachedCount += 1;
+    const translatedRow = current.rows.get(item.id);
+    if (translatedRow) current.observer?.unobserve(translatedRow);
+    renderTranslation(current, item.id, item);
+    if (segment.kind === "cell") {
+      void chrome.tabs.sendMessage(current.tabId, {
+        type: "YIDU_RENDER_CELLS",
+        payload: { items: [{ id: item.id, translation: item.translation }] }
+      }).catch(() => undefined);
+    }
+    updateSummaryArticleTitle(current, segment);
+    updateProgress(current);
+  }
+
   function renderTranslation(current, id, item) {
     const row = current.rows.get(id);
     const segment = current.segmentsById.get(id);
@@ -656,13 +667,13 @@ import { groupArticleModules } from "./lib/summary.js";
     let text = plainTranslationText(item.translation);
     if (/^h[1-6]$/.test(segment.kind)) text = cleanHeadingText(text);
     row.textContent = text;
-    if (current.completed.has(id)) {
-      row.classList.remove("yidu-pending", "yidu-refreshing");
-      row.removeAttribute("aria-busy");
-      row.dataset.translated = "true";
-    }
-  }
-
+    if (current.completed.has(id)) {
+      row.classList.remove("yidu-pending", "yidu-refreshing");
+      row.removeAttribute("aria-busy");
+      row.dataset.translated = "true";
+    }
+  }
+
   function cleanHeadingText(value) {
     return String(value || "").replace(/^\s*[:：]\s*/, "");
   }
@@ -674,71 +685,71 @@ import { groupArticleModules } from "./lib/summary.js";
     template.content.querySelectorAll("br").forEach((node) => node.replaceWith("\n"));
     return template.content.textContent || "";
   }
-
-  function showError(current, message, setupRequired) {
-    setStatus("");
-    document.querySelector(".yidu-error")?.remove();
-    const box = document.createElement("section");
-    box.className = "yidu-error";
-    const title = document.createElement("strong");
-    title.textContent = message;
-    const detail = document.createElement("span");
-    detail.textContent = setupRequired ? "填写密钥后即可继续。" : "已完成的翻译会保留。";
-    const actions = document.createElement("div");
-    actions.className = "yidu-actions";
-    const button = document.createElement("button");
-    button.className = "yidu-action";
-    button.type = "button";
-    button.textContent = setupRequired ? "打开设置" : "重试";
-    button.addEventListener("click", () => {
-      if (setupRequired) {
-        chrome.runtime.sendMessage({ type: "YIDU_OPEN_OPTIONS" });
-        return;
-      }
-      box.remove();
-      current.failed = false;
-      current.failedSegments.splice(0).forEach((segment) => enqueue(current, segment));
-    });
-    actions.append(button);
-    box.append(title, detail, actions);
-    content.prepend(box);
-  }
-
-  function showEmpty(message, retryable) {
-    content.setAttribute("aria-busy", "false");
-    setStatus("");
-    const box = document.createElement("section");
-    box.className = "yidu-empty";
-    const title = document.createElement("strong");
-    title.textContent = message;
-    box.append(title);
-    if (retryable) {
-      const actions = document.createElement("div");
-      actions.className = "yidu-actions";
-      const retry = document.createElement("button");
-      retry.className = "yidu-action secondary";
-      retry.type = "button";
-      retry.textContent = "重新读取";
-      retry.addEventListener("click", () => void loadActiveArticle());
-      actions.append(retry);
-      box.append(actions);
-    }
-    content.replaceChildren(box);
-  }
-
-  function updateProgress(current, activeBatchSize = 0) {
-    if (current.stopped || current.failed) return;
-    setStatus(activeBatchSize || current.working ? "正在翻译…" : "");
-  }
-
-  function setStatus(message) {
-    status.textContent = message;
-  }
-
-  function stopSession() {
-    if (!session) return;
-    session.stopped = true;
-    session.observer?.disconnect();
-    session = null;
-  }
-})();
+
+  function showError(current, message, setupRequired) {
+    setStatus("");
+    document.querySelector(".yidu-error")?.remove();
+    const box = document.createElement("section");
+    box.className = "yidu-error";
+    const title = document.createElement("strong");
+    title.textContent = message;
+    const detail = document.createElement("span");
+    detail.textContent = setupRequired ? "填写密钥后即可继续。" : "已完成的翻译会保留。";
+    const actions = document.createElement("div");
+    actions.className = "yidu-actions";
+    const button = document.createElement("button");
+    button.className = "yidu-action";
+    button.type = "button";
+    button.textContent = setupRequired ? "打开设置" : "重试";
+    button.addEventListener("click", () => {
+      if (setupRequired) {
+        chrome.runtime.sendMessage({ type: "YIDU_OPEN_OPTIONS" });
+        return;
+      }
+      box.remove();
+      current.failed = false;
+      current.failedSegments.splice(0).forEach((segment) => enqueue(current, segment));
+    });
+    actions.append(button);
+    box.append(title, detail, actions);
+    content.prepend(box);
+  }
+
+  function showEmpty(message, retryable) {
+    content.setAttribute("aria-busy", "false");
+    setStatus("");
+    const box = document.createElement("section");
+    box.className = "yidu-empty";
+    const title = document.createElement("strong");
+    title.textContent = message;
+    box.append(title);
+    if (retryable) {
+      const actions = document.createElement("div");
+      actions.className = "yidu-actions";
+      const retry = document.createElement("button");
+      retry.className = "yidu-action secondary";
+      retry.type = "button";
+      retry.textContent = "重新读取";
+      retry.addEventListener("click", () => void loadActiveArticle());
+      actions.append(retry);
+      box.append(actions);
+    }
+    content.replaceChildren(box);
+  }
+
+  function updateProgress(current, activeBatchSize = 0) {
+    if (current.stopped || current.failed) return;
+    setStatus(activeBatchSize || current.working ? "正在翻译…" : "");
+  }
+
+  function setStatus(message) {
+    status.textContent = message;
+  }
+
+  function stopSession() {
+    if (!session) return;
+    session.stopped = true;
+    session.observer?.disconnect();
+    session = null;
+  }
+})();
diff --git a/tests/extension.test.mjs b/tests/extension.test.mjs
index 8f3a845..cd3c6bb 100644
--- a/tests/extension.test.mjs
+++ b/tests/extension.test.mjs
@@ -149,3 +149,16 @@ test("loads settings before enabling input and verifies persistence", () => {
   assert.match(optionsScript, /SUMMARY_STORAGE_KEY/);
   assert.match(optionsScript, /chrome\.storage\.local\.remove/);
 });
+
+test("gates the selection menu behind an open side panel", () => {
+  assert.match(panelScript, /chrome\.runtime\.connect\(\{ name: `yidu-panel-open:\$\{tab\.id\}` \}\)/);
+  assert.match(background, /chrome\.runtime\.onConnect\.addListener/);
+  assert.match(background, /yidu-panel-open:/);
+  assert.match(background, /panelOpenTabs\.add\(tabId\)/);
+  assert.match(background, /panelOpenTabs\.delete\(tabId\)/);
+  assert.match(background, /YIDU_PANEL_STATE_QUERY/);
+  assert.match(content, /YIDU_PANEL_STATE/);
+  assert.match(content, /YIDU_PANEL_STATE_QUERY/);
+  assert.match(content, /let panelOpen = false/);
+  assert.match(content, /if \(!panelOpen\) \{\s*hideSelectionUi\(\);/);
+});
diff --git a/tests/release.test.mjs b/tests/release.test.mjs
index 74ff3b8..38fb003 100644
--- a/tests/release.test.mjs
+++ b/tests/release.test.mjs
@@ -20,7 +20,7 @@ test("public release metadata is complete and consistent", async () => {
 
   assert.match(readme, /^# 译读 ImmerRead/m);
   assert.match(readme, /\*\*中文\*\* \| \[English\]\(#english\)/);
-  assert.match(readme, /demo\/article-translator\/final-desktop\.png/);
+  assert.match(readme, /demo\/article-translator\/[\w-]+\.(png|jpe?g)/);
   assert.match(readme, /github\.com\/dolphin-boop\/immerread/);
   assert.doesNotMatch(readme, /github\.com\/dolphin-boop\/yidu/);
   assert.doesNotMatch(readme, /github\.com\/joeseesun\//);