diff --git a/emrg/gui/renderer/index.html b/emrg/gui/renderer/index.html
index e7c3271..9715252 100644
--- a/emrg/gui/renderer/index.html
+++ b/emrg/gui/renderer/index.html
@@ -20,14 +20,14 @@
         <span>EMRG</span>
       </div>
       <!-- 成长状态卡（WorkBuddy P3：自进化可见化；#501） -->
-      <div class="growth-card" id="growth-card" title="EMRG 每次自我改进都会自动汇报">
+      <div class="growth-card" id="growth-card" title="EMRG 每次自我改进都会自动汇报" data-i18n-title="copy.growthCardTitle">
         <div class="growth-line">🌱 <span data-i18n="copy.growthCountPrefix">已自我进化</span> <b id="growth-count">0</b> <span data-i18n="copy.times">次</span></div>
-        <div class="growth-note" id="growth-note">边工作边学习，越用越懂你</div>
+        <div class="growth-note" id="growth-note" data-i18n="copy.growthNote">边工作边学习，越用越懂你</div>
       </div>
       <button id="new-chat-btn" class="new-chat-btn" title="新对话 (⌘N)" data-i18n="sidebar.newChat" data-i18n-title="sidebar.newChatTitle">＋ 新对话</button>
       <nav id="conv-list"></nav>
       <div class="sidebar-footer">
-        <span id="status-dot" class="status-dot gray" title="连接状态"></span>
+        <span id="status-dot" class="status-dot gray" title="连接状态" data-i18n-title="sidebar.statusTitle"></span>
         <button id="settings-btn" class="btn btn-ghost" style="margin-left:auto;padding:6px 12px;min-height:30px;" data-i18n="sidebar.settings">设置</button>
       </div>
     </aside>
@@ -40,7 +40,7 @@
       <!-- 聊天区 -->
       <div id="chat-view"></div>
       <!-- 回到底部悬浮按钮（上滑阅读时出现） -->
-      <button id="back-to-bottom" class="back-to-bottom hidden" title="回到底部">↓</button>
+      <button id="back-to-bottom" class="back-to-bottom hidden" title="回到底部" data-i18n-title="sidebar.backToBottom">↓</button>
 
       <!-- 空状态欢迎屏 -->
       <div id="empty-state" class="hidden">
@@ -98,7 +98,7 @@ <h2 data-i18n="settings.title">设置</h2>
         <div id="model-form" class="model-form hidden">
           <div class="model-form-row">
             <label class="model-form-label" data-i18n="settings.name">名称
-              <input type="text" id="model-form-name" placeholder="如 deepseek-v3" maxlength="40" />
+              <input type="text" id="model-form-name" placeholder="如 deepseek-v3" maxlength="40" data-i18n-placeholder="settings.modelNamePlaceholder" />
             </label>
             <label class="model-form-label" data-i18n="settings.modelId">模型 ID（选填）
               <input type="text" id="model-form-id" placeholder="默认同名称" maxlength="60" data-i18n-placeholder="settings.modelIdPlaceholder" />
@@ -144,15 +144,15 @@ <h2 data-i18n="settings.title">设置</h2>
         </label>
       </div>
       <div class="settings-group">
-        <div class="settings-group-title">关于</div>
+        <div class="settings-group-title" data-i18n="settings.aboutTitle">关于</div>
         <div class="about-box">
           <div class="about-line">EMRG <span id="about-version">v0.2.8</span> · <span id="about-evolutions">🌱 <span data-i18n="copy.growthCountPrefix">已自我进化</span> 0 <span data-i18n="copy.times">次</span></span></div>
-          <div class="hint" style="margin-top:6px;">EMRG 是一个会自我进化的 AI 智能体——每次改进都会自动汇报，你可以随时在这里看到它的成长。</div>
+          <div class="hint" style="margin-top:6px;" data-i18n="settings.aboutDesc">EMRG 是一个会自我进化的 AI 智能体——每次改进都会自动汇报，你可以随时在这里看到它的成长。</div>
         </div>
       </div>
       <!-- WorkBuddy P3：最近改进列表（daemon evolution_summary） -->
       <div class="settings-group">
-        <div class="settings-group-title">最近改进</div>
+        <div class="settings-group-title" data-i18n="settings.recentTitle">最近改进</div>
         <div id="about-recent" class="about-recent"></div>
       </div>
       <div class="dialog-actions">
@@ -316,11 +316,11 @@ <h2 data-i18n="tasks.title">后台任务</h2>
 
   <!-- 进化完成 toast（WorkBuddy P3：进化发生时温和提示） -->
   <div id="evolution-toast" class="evolution-toast hidden">
-    <div class="evolution-toast-title">🌱 EMRG 刚刚完成一次自我进化！</div>
-    <div class="evolution-toast-msg" id="evolution-toast-msg">它学会了新的东西，变得更好用了。</div>
+    <div class="evolution-toast-title" data-i18n="copy.evolutionToastTitle">🌱 EMRG 刚刚完成一次自我进化！</div>
+    <div class="evolution-toast-msg" id="evolution-toast-msg" data-i18n="copy.evolutionToastMsgStatic">它学会了新的东西，变得更好用了。</div>
     <div class="evolution-toast-actions">
-      <button type="button" id="evolution-toast-see" class="btn btn-primary">去看看</button>
-      <button type="button" id="evolution-toast-dismiss" class="btn btn-ghost">知道了</button>
+      <button type="button" id="evolution-toast-see" class="btn btn-primary" data-i18n="copy.evolutionToastSee">去看看</button>
+      <button type="button" id="evolution-toast-dismiss" class="btn btn-ghost" data-i18n="copy.evolutionToastDismiss">知道了</button>
     </div>
   </div>
 
diff --git a/emrg/gui/renderer/js/i18n.js b/emrg/gui/renderer/js/i18n.js
index aa82ba2..259efa2 100644
--- a/emrg/gui/renderer/js/i18n.js
+++ b/emrg/gui/renderer/js/i18n.js
@@ -20,6 +20,8 @@ const I18N = (() => {
       "sidebar.newChat": "＋ 新对话",
       "sidebar.newChatTitle": "新对话 (⌘N)",
       "sidebar.settings": "设置",
+      "sidebar.statusTitle": "连接状态",
+      "sidebar.backToBottom": "回到底部",
 
       // 空状态欢迎屏
       "empty.hello": "你好，我是 EMRG",
@@ -52,10 +54,14 @@ const I18N = (() => {
       "settings.availableModels": "可用模型",
       "settings.addModel": "＋ 添加模型",
       "settings.name": "名称",
+      "settings.modelNamePlaceholder": "如 deepseek-v3",
       "settings.modelId": "模型 ID（选填）",
       "settings.modelIdPlaceholder": "默认同名称",
       "settings.vision": "支持图片",
       "settings.cancel": "取消",
+      "settings.aboutTitle": "关于",
+      "settings.aboutDesc": "EMRG 是一个会自我进化的 AI 智能体——每次改进都会自动汇报，你可以随时在这里看到它的成长。",
+      "settings.recentTitle": "最近改进",
       "settings.saveModel": "保存模型",
       "settings.defaultHint": "点左侧圆点可设为默认模型，切换后下一条消息即生效",
       "settings.groupWorkdir": "工作目录",
@@ -147,12 +153,14 @@ const I18N = (() => {
       "copy.aboutEvolution": "EMRG 已自我成长 {n} 次，感谢你的每一次反馈",
       "copy.aboutEvolutionEmpty": "EMRG 正在成长中",
       // WorkBuddy P3（#501）：成长卡 + 进化 toast
+      "copy.growthCardTitle": "EMRG 每次自我改进都会自动汇报",
       "copy.growthCount": "已自我进化 {n} 次",
       "copy.growthCountPrefix": "已自我进化",
       "copy.times": "次",
       "copy.growthNote": "边工作边学习，越用越懂你",
       "copy.evolutionToastTitle": "EMRG 刚刚完成一次自我进化！",
       "copy.evolutionToastMsg": "这是它的第 {n} 次自我改进，现在更好用了。",
+      "copy.evolutionToastMsgStatic": "它学会了新的东西，变得更好用了。",
       "copy.evolutionToastSee": "去看看",
       "copy.evolutionToastDismiss": "知道了",
 
@@ -272,6 +280,8 @@ const I18N = (() => {
       "sidebar.newChat": "＋ New chat",
       "sidebar.newChatTitle": "New chat (⌘N)",
       "sidebar.settings": "Settings",
+      "sidebar.statusTitle": "Connection status",
+      "sidebar.backToBottom": "Back to bottom",
 
       // Empty state
       "empty.hello": "Hi, I'm EMRG",
@@ -304,10 +314,14 @@ const I18N = (() => {
       "settings.availableModels": "Available models",
       "settings.addModel": "＋ Add model",
       "settings.name": "Name",
+      "settings.modelNamePlaceholder": "e.g. deepseek-v3",
       "settings.modelId": "Model ID (optional)",
       "settings.modelIdPlaceholder": "Defaults to name",
       "settings.vision": "Supports images",
       "settings.cancel": "Cancel",
+      "settings.aboutTitle": "About",
+      "settings.aboutDesc": "EMRG is a self-evolving AI agent — it reports every improvement, and you can watch it grow right here.",
+      "settings.recentTitle": "Recent improvements",
       "settings.saveModel": "Save model",
       "settings.defaultHint": "Click the dot on the left to set the default model — takes effect on the next message",
       "settings.groupWorkdir": "Working directory",
@@ -399,12 +413,14 @@ const I18N = (() => {
       "copy.aboutEvolution": "EMRG has self-evolved {n} times — thanks for every bit of feedback",
       "copy.aboutEvolutionEmpty": "EMRG is still growing",
       // WorkBuddy P3 (#501): growth card + evolution toast
+      "copy.growthCardTitle": "EMRG reports every self-improvement automatically",
       "copy.growthCount": "Self-evolved {n} times",
       "copy.growthCountPrefix": "Self-evolved",
       "copy.times": "times",
       "copy.growthNote": "Learning as I work — getting better with use",
       "copy.evolutionToastTitle": "EMRG just completed a self-evolution!",
       "copy.evolutionToastMsg": "That's its {n}th self-improvement — it's even better now.",
+      "copy.evolutionToastMsgStatic": "It learned something new and is even better now.",
       "copy.evolutionToastSee": "See details",
       "copy.evolutionToastDismiss": "Got it",
 
diff --git a/emrg/gui/test/i18n.test.js b/emrg/gui/test/i18n.test.js
index 3a00a0d..bcf2b7a 100644
--- a/emrg/gui/test/i18n.test.js
+++ b/emrg/gui/test/i18n.test.js
@@ -161,3 +161,33 @@ test("Stage2：成长卡/关于区静态文案键（#501 吸收）", () => {
   const { ctx: zh } = makeSandbox({ navigator: { language: "zh-CN" } });
   assert.strictEqual(evalIn(zh, 'I18N.t("copy.growthCount", { n: 7 })'), "已自我进化 7 次");
 });
+
+// ── Stage 3（cycle 20260806-225341）：index.html 无遗漏硬编码中文 ──
+test("Stage3：index.html 中文字符串必须带 data-i18n（防漏网回归）", () => {
+  const html = fs.readFileSync(path.join(__dirname, "..", "renderer", "index.html"), "utf8");
+  const cjk = /[\u4e00-\u9fff]/;
+  const leaks = [];
+  for (const [i, line] of html.split("\n").entries()) {
+    const s = line.trim();
+    if (!cjk.test(s)) continue;            // 无中文
+    if (s.startsWith("<!--")) continue;    // HTML 注释
+    if (s.includes("data-i18n")) continue; // 已接入 i18n（含 data-i18n-title/placeholder）
+    leaks.push(`L${i + 1}: ${s.slice(0, 80)}`);
+  }
+  assert.strictEqual(leaks.length, 0, "index.html 存在未接入 i18n 的中文（补 data-i18n 或 data-i18n-title/placeholder）:\n" + leaks.join("\n"));
+});
+
+test("Stage3：新增静态键双语一致（growth-card title / about / status-dot / toast 静态）", () => {
+  const { ctx } = makeSandbox({ navigator: { language: "en-US" } });
+  assert.strictEqual(evalIn(ctx, 'I18N.t("copy.growthCardTitle")'), "EMRG reports every self-improvement automatically");
+  assert.strictEqual(evalIn(ctx, 'I18N.t("sidebar.statusTitle")'), "Connection status");
+  assert.strictEqual(evalIn(ctx, 'I18N.t("sidebar.backToBottom")'), "Back to bottom");
+  assert.strictEqual(evalIn(ctx, 'I18N.t("settings.aboutTitle")'), "About");
+  assert.strictEqual(evalIn(ctx, 'I18N.t("settings.recentTitle")'), "Recent improvements");
+  assert.strictEqual(evalIn(ctx, 'I18N.t("settings.modelNamePlaceholder")'), "e.g. deepseek-v3");
+  assert.strictEqual(evalIn(ctx, 'I18N.t("copy.evolutionToastMsgStatic")'), "It learned something new and is even better now.");
+  const { ctx: zh } = makeSandbox({ navigator: { language: "zh-CN" } });
+  assert.strictEqual(evalIn(zh, 'I18N.t("settings.aboutTitle")'), "关于");
+  assert.strictEqual(evalIn(zh, 'I18N.t("settings.recentTitle")'), "最近改进");
+  assert.strictEqual(evalIn(zh, 'I18N.t("sidebar.backToBottom")'), "回到底部");
+});