diff --git a/frontend/src/App.tsx b/frontend/src/App.tsx
index bd9eb19..444451e 100644
--- a/frontend/src/App.tsx
+++ b/frontend/src/App.tsx
@@ -107,7 +107,9 @@ function HomeView() {
       <StatsBar servers={servers} config={config} exchangeRates={exchangeRates} />
       {config.show_search || config.show_groups ? <div className="toolbar">
         {config.show_search ? <div className="search-box"><Search size={16} /><input aria-label={ui(locale, "搜索节点", "Search servers")} placeholder={ui(locale, "搜索节点", "Search servers")} value={query} onChange={(event) => setQuery(event.target.value)} /></div> : null}
-        {config.show_groups ? <div className="group-tabs" aria-label={ui(locale, "节点分组", "Server groups")}>{groups.map((item) => <button className={group === item ? "active" : ""} key={item} onClick={() => setGroup(item)}>{item === "__all__" ? ui(locale, "全部", "All") : item}</button>)}</div> : null}
+        {/* role="group" 让 aria-label 生效（无 role 的 div 是 generic，规范禁止命名，标签会被丢掉）；
+            选中态用 aria-pressed，不用 role="radio"，避免欠下方向键 + roving tabindex 的实现。 */}
+        {config.show_groups ? <div className="group-tabs" role="group" aria-label={ui(locale, "节点分组", "Server groups")}>{groups.map((item) => <button className={group === item ? "active" : ""} aria-pressed={group === item} key={item} onClick={() => setGroup(item)}>{item === "__all__" ? ui(locale, "全部", "All") : item}</button>)}</div> : null}
         <span className="result-count">{ui(locale, `${visible.length} 个节点`, `${visible.length} servers`)}</span>
       </div> : null}
       {error ? <div className="error-band"><span>{error}</span><button onClick={() => void reload()}>{ui(locale, "重试", "Retry")}</button></div> : null}
diff --git a/frontend/src/components/AdminPanel.tsx b/frontend/src/components/AdminPanel.tsx
index 946e4cd..d452b31 100644
--- a/frontend/src/components/AdminPanel.tsx
+++ b/frontend/src/components/AdminPanel.tsx
@@ -518,18 +518,20 @@ export function AdminPanel({
 
   return (
     <div className={`admin-page ${dark ? "admin-dark" : ""}`}>
-      {error ? <div className="admin-toast error" role="alert" aria-live="assertive"><CircleAlert aria-hidden="true" /><span>{error}</span></div>
-        : notice ? <div className="admin-toast" role="status" aria-live="polite"><CircleCheck aria-hidden="true" /><span>{notice}</span></div> : null}
+      {/* toast 的定位是按后台的顶栏算的；登录页没有顶栏，那里的错误走表单内提示 */}
+      {authenticated ? (error ? <div className="admin-toast error" role="alert" aria-live="assertive"><CircleAlert aria-hidden="true" /><span>{error}</span></div>
+        : notice ? <div className="admin-toast" role="status" aria-live="polite"><CircleCheck aria-hidden="true" /><span>{notice}</span></div> : null) : null}
       {!authenticated ? <div className="admin-login-stage">
-        <button className="admin-back" type="button" onClick={onClose}><ArrowLeft size={14} />返回</button>
-        <button className="admin-login-theme" type="button" onClick={onToggleTheme} title={dark ? "切换浅色主题" : "切换深色主题"}>{dark ? <Sun size={16} /> : <Moon size={16} />}</button>
+        <button className="admin-back" type="button" onClick={onClose}><ArrowLeft size={15} />返回</button>
+        <button className="admin-login-theme" type="button" onClick={onToggleTheme} title={dark ? "切换浅色主题" : "切换深色主题"}>{dark ? <Sun size={15} /> : <Moon size={15} />}</button>
         <form className="login-form glass-panel" onSubmit={login}>
           <SiteLogo src={siteLogoUrl} alt="" width="48" height="48" />
-          <div className="login-copy"><h1>管理员登录</h1></div>
-          <label><span>用户名</span><input autoFocus type="text" autoComplete="username" value={username} onChange={(event) => setUsername(event.target.value)} required /></label>
-          <label><span>密码</span><input type="password" autoComplete="current-password" value={password} onChange={(event) => setPassword(event.target.value)} required /></label>
+          <div className="login-copy"><h1>管理员登录</h1><p>{config.site_name}</p></div>
+          <label><span>用户名</span><input autoFocus type="text" autoComplete="username" value={username} onChange={(event) => setUsername(event.target.value)} required aria-invalid={error ? true : undefined} aria-describedby={error ? "login-error" : undefined} /></label>
+          <label><span>密码</span><input type="password" autoComplete="current-password" value={password} onChange={(event) => setPassword(event.target.value)} required aria-invalid={error ? true : undefined} aria-describedby={error ? "login-error" : undefined} /></label>
           {config.turnstile_login_enabled || config.turnstile_enabled ? <div className="login-turnstile"><TurnstileWidget siteKey={config.turnstile_site_key} action="admin-login" theme={dark ? "dark" : "light"} resetKey={turnstileReset} onVerify={setTurnstileToken} onError={setError} /></div> : null}
-          <button className="primary-btn login-submit" disabled={busy || ((config.turnstile_login_enabled || config.turnstile_enabled) && !turnstileToken)} type="submit"><KeyRound size={16} />{busy ? "验证中" : "登录"}</button>
+          {error ? <p className="login-error" id="login-error" role="alert"><CircleAlert size={15} aria-hidden="true" />{error}</p> : null}
+          <button className="primary-btn login-submit" disabled={busy || ((config.turnstile_login_enabled || config.turnstile_enabled) && !turnstileToken)} type="submit"><KeyRound size={15} />{busy ? "验证中" : "登录"}</button>
         </form>
       </div> : <section className="admin-shell" aria-label="管理面板">
         <header className="admin-topbar">
@@ -538,33 +540,38 @@ export function AdminPanel({
             <strong>{config.site_name}</strong>
           </div>
           <div className="admin-topbar-actions">
-            <button type="button" onClick={onToggleTheme} title={dark ? "切换浅色主题" : "切换深色主题"} aria-label={dark ? "切换浅色主题" : "切换深色主题"}>{dark ? <Sun size={17} /> : <Moon size={17} />}</button>
-            <button type="button" onClick={onClose} title="主页" aria-label="主页"><ArrowLeft size={17} />主页</button>
-            <button type="button" onClick={() => void logout()} title="退出" aria-label="退出"><LogOut size={17} />退出</button>
+            <button type="button" onClick={onToggleTheme} title={dark ? "切换浅色主题" : "切换深色主题"} aria-label={dark ? "切换浅色主题" : "切换深色主题"}>{dark ? <Sun size={15} /> : <Moon size={15} />}</button>
+            <button type="button" onClick={onClose} title="主页" aria-label="主页"><ArrowLeft size={15} />主页</button>
+            <button type="button" onClick={() => void logout()} title="退出" aria-label="退出"><LogOut size={15} />退出</button>
           </div>
         </header>
 
           <div className="admin-body">
             <aside className="admin-sidebar">
-              <span className="admin-nav-label">管理</span>
-              <nav className="admin-tabs">
-                <button className={tab === "servers" ? "active" : ""} onClick={() => selectTab("servers")}><ServerCog size={19} />服务器</button>
-                <button className={tab === "latency" ? "active" : ""} onClick={() => selectTab("latency")}><RadioTower size={19} />延迟检测</button>
-                <button className={tab === "appearance" ? "active" : ""} onClick={() => selectTab("appearance")}><Eye size={19} />站点设置</button>
-                <button className={tab === "themes" ? "active" : ""} onClick={() => selectTab("themes")}><Palette size={19} />主题商店</button>
-                <button className={tab === "themeSettings" ? "active" : ""} onClick={() => { selectTab("themeSettings"); void loadThemeSettings(); }}><SlidersHorizontal size={19} />主题设置</button>
-                <button className={tab === "alerts" ? "active" : ""} onClick={() => selectTab("alerts")}><AlertTriangle size={19} />通知</button>
-                <button className={tab === "security" ? "active" : ""} onClick={() => selectTab("security")}><ShieldCheck size={19} />登录与安全</button>
-                <button className={tab === "data" ? "active" : ""} onClick={() => { selectTab("data"); if (!database) void loadDatabase(); }}><Database size={19} />监控数据库</button>
-                <button className={tab === "about" ? "active" : ""} onClick={() => selectTab("about")}><Info size={19} />关于</button>
+              {/* 这个 span 在窄屏是 display:none，但被 aria-labelledby 直接引用的节点即使隐藏也参与名称计算，
+                  所以地标名在所有断点都在，不用另写一份 aria-label。 */}
+              <span className="admin-nav-label" id="admin-nav-label">管理</span>
+              {/* 用 nav + aria-current 而不是 role="tablist"：tablist 会盖掉 nav 的导航地标，
+                  且 APG 的 tab 模式要求方向键 + roving tabindex，而主题设置和监控数据库点了要发请求，
+                  方向键扫过就会连带触发。每项换的是整块内容和它自己的 h1，本质是页内导航，不是 tab 面板。 */}
+              <nav className="admin-tabs" aria-labelledby="admin-nav-label">
+                <button type="button" className={tab === "servers" ? "active" : ""} aria-current={tab === "servers" ? "page" : undefined} onClick={() => selectTab("servers")}><ServerCog size={17} />服务器</button>
+                <button type="button" className={tab === "latency" ? "active" : ""} aria-current={tab === "latency" ? "page" : undefined} onClick={() => selectTab("latency")}><RadioTower size={17} />延迟检测</button>
+                <button type="button" className={tab === "appearance" ? "active" : ""} aria-current={tab === "appearance" ? "page" : undefined} onClick={() => selectTab("appearance")}><Eye size={17} />站点设置</button>
+                <button type="button" className={tab === "themes" ? "active" : ""} aria-current={tab === "themes" ? "page" : undefined} onClick={() => selectTab("themes")}><Palette size={17} />主题商店</button>
+                <button type="button" className={tab === "themeSettings" ? "active" : ""} aria-current={tab === "themeSettings" ? "page" : undefined} onClick={() => { selectTab("themeSettings"); void loadThemeSettings(); }}><SlidersHorizontal size={17} />主题设置</button>
+                <button type="button" className={tab === "alerts" ? "active" : ""} aria-current={tab === "alerts" ? "page" : undefined} onClick={() => selectTab("alerts")}><AlertTriangle size={17} />通知</button>
+                <button type="button" className={tab === "security" ? "active" : ""} aria-current={tab === "security" ? "page" : undefined} onClick={() => selectTab("security")}><ShieldCheck size={17} />登录与安全</button>
+                <button type="button" className={tab === "data" ? "active" : ""} aria-current={tab === "data" ? "page" : undefined} onClick={() => { selectTab("data"); if (!database) void loadDatabase(); }}><Database size={17} />监控数据库</button>
+                <button type="button" className={tab === "about" ? "active" : ""} aria-current={tab === "about" ? "page" : undefined} onClick={() => selectTab("about")}><Info size={17} />关于</button>
               </nav>
             </aside>
             <div className="admin-content">
               <header className="admin-content-header"><h1>{adminPages[tab].title}</h1><p>{adminPages[tab].description}</p></header>
               {tab === "servers" ? (
                 <div className="admin-section">
-                  <div className="section-head"><div><h3>监控节点</h3><span>{servers.length} 个节点 · 可拖动上下排序</span></div><div className="section-actions"><button className="primary-btn compact" onClick={() => openEditor()}><Plus size={16} />添加</button></div></div>
-                  <div className="batch-toolbar"><label className="select-all"><Checkbox checked={allSelected} onChange={() => setSelectedIds(allSelected ? [] : servers.map((server) => server.id))} />全选</label>{selectedIds.length ? <button className="danger-btn compact" onClick={() => void removeSelected()}><Trash2 size={14} />删除选中 ({selectedIds.length})</button> : <span>批量操作</span>}</div>
+                  <div className="section-head"><div><h3>监控节点</h3><span>{servers.length} 个节点 · 可拖动上下排序</span></div><div className="section-actions"><button className="primary-btn compact" onClick={() => openEditor()}><Plus size={15} />添加</button></div></div>
+                  <div className="batch-toolbar"><label className="select-all"><Checkbox checked={allSelected} onChange={() => setSelectedIds(allSelected ? [] : servers.map((server) => server.id))} />全选</label>{selectedIds.length ? <button className="danger-btn compact" onClick={() => void removeSelected()}><Trash2 size={15} />删除选中 ({selectedIds.length})</button> : <span>批量操作</span>}</div>
                   <div className="server-list">
                     {servers.map((server, index) => (
                       <div className={`server-row ${draggingId === server.id ? "dragging" : ""}`} key={server.id} onDragOver={(event) => { event.preventDefault(); event.dataTransfer.dropEffect = "move"; }} onDrop={(event) => void dropServer(event, server.id)}>
@@ -592,8 +599,8 @@ export function AdminPanel({
                           {!theme.builtin ? <a href={theme.url} target="_blank" rel="noreferrer"><span>{theme.url}</span><ExternalLink size={13} /></a> : null}
                         </div>
                         <div className="theme-row-actions">
-                          {!theme.builtin ? <button type="button" className="secondary-btn compact" disabled={busy} onClick={() => void previewTheme(theme)}><Eye size={14} />预览</button> : null}
-                          <button type="button" className={theme.active ? "theme-active-btn" : "primary-btn compact"} disabled={busy || theme.active} onClick={() => void activateTheme(theme)}>{theme.active ? <><Check size={14} />使用中</> : "启用"}</button>
+                          {!theme.builtin ? <button type="button" className="secondary-btn compact" disabled={busy} onClick={() => void previewTheme(theme)}><Eye size={15} />预览</button> : null}
+                          <button type="button" className={theme.active ? "theme-active-btn" : "primary-btn compact"} disabled={busy || theme.active} onClick={() => void activateTheme(theme)}>{theme.active ? <><Check size={15} />使用中</> : "启用"}</button>
                           {!theme.builtin ? <button type="button" className="icon-btn danger" disabled={busy} title="删除主题" onClick={() => void removeTheme(theme)}><Trash2 size={15} /></button> : null}
                         </div>
                       </article>)}
@@ -604,7 +611,7 @@ export function AdminPanel({
                     <p className="settings-hint">仅支持 GitHub 地址</p>
                     <div className="form-grid"><label><span>主题名称</span><input required maxLength={80} value={themeName} onChange={(event) => setThemeName(event.target.value)} placeholder="例如：Ocean" /></label><label><span>主题 URL</span><input required type="url" maxLength={2048} value={themeUrl} onChange={(event) => setThemeUrl(event.target.value)} placeholder="https://github.com/user/theme" /></label></div>
                     <label><span>主题说明（可选）</span><textarea rows={2} maxLength={300} value={themeDescription} onChange={(event) => setThemeDescription(event.target.value)} placeholder="简短描述主题风格和来源" /></label>
-                    <div className="form-actions"><button className="primary-btn" disabled={busy}><Plus size={16} />添加主题</button></div>
+                    <div className="form-actions"><button className="primary-btn" disabled={busy}><Plus size={15} />添加主题</button></div>
                   </form>
                 </div>
               ) : settings && tab !== "about" ? (
@@ -647,20 +654,20 @@ export function AdminPanel({
                     <div className="section-title"><Database size={15} />D1 数据维护</div>
                     <div className="data-stat-grid">{database ? <><DataStat label="节点" value={database.server_count} /><DataStat label="在线" value={database.online_count} /><DataStat label="历史行数" value={database.history_rows.toLocaleString()} /></> : <p className="settings-hint">正在读取数据库统计...</p>}</div>
                     <div className="usage-section">
-                      <div className="usage-head"><div><div className="section-title"><Coins size={15} />每日汇率</div><p className="settings-hint">{exchangeRates ? `${exchangeRates.source} · ${exchangeRates.date || "等待首次更新"}${exchangeRates.stale ? " · 数据待更新" : ""}` : "正在读取 D1 汇率快照"}</p></div><button type="button" className="secondary-btn compact" disabled={busy} onClick={() => void refreshExchangeRates()}><RotateCw size={14} />立即更新</button></div>
+                      <div className="usage-head"><div><div className="section-title"><Coins size={15} />每日汇率</div><p className="settings-hint">{exchangeRates ? `${exchangeRates.source} · ${exchangeRates.date || "等待首次更新"}${exchangeRates.stale ? " · 数据待更新" : ""}` : "正在读取 D1 汇率快照"}</p></div><button type="button" className="secondary-btn compact" disabled={busy} onClick={() => void refreshExchangeRates()}><RotateCw size={15} />立即更新</button></div>
                       {exchangeRates ? <div className="usage-table-wrap"><table className="usage-table"><thead><tr><th>币种</th><th>1 CNY 可兑换</th></tr></thead><tbody>{ASSET_CURRENCIES.map((currency) => <tr key={currency}><th scope="row">{currency}</th><td>{exchangeRates.rates[currency]?.toLocaleString(undefined, { maximumFractionDigits: 6 }) ?? "--"}</td></tr>)}</tbody></table></div> : <div className="usage-empty">尚未读取</div>}
                     </div>
                     <div className="usage-section">
-                      <div className="usage-head"><div><div className="section-title"><Cloud size={15} />Cloudflare 用量</div><p className="settings-hint">统计周期使用 UTC</p></div><button type="button" className="secondary-btn compact" disabled={busy} onClick={() => void loadCloudflareUsage()}><RotateCw size={14} />{cloudflareUsage ? "刷新用量" : "查询用量"}</button></div>
+                      <div className="usage-head"><div><div className="section-title"><Cloud size={15} />Cloudflare 用量</div><p className="settings-hint">统计周期使用 UTC</p></div><button type="button" className="secondary-btn compact" disabled={busy} onClick={() => void loadCloudflareUsage()}><RotateCw size={15} />{cloudflareUsage ? "刷新用量" : "查询用量"}</button></div>
                       <div className="form-grid"><label><span>Cloudflare Account ID</span><input autoComplete="off" type="password" maxLength={32} value={settings.cloudflare_account_id} onChange={(event) => updateSettings("cloudflare_account_id", event.target.value)} placeholder="32 位账户 ID" /></label><label><span>Cloudflare API Token</span><input autoComplete="off" type="password" value={settings.cloudflare_api_token} onChange={(event) => updateSettings("cloudflare_api_token", event.target.value)} placeholder="Account Analytics: Read" /></label></div>
-                      <div className="usage-config-actions"><p className="settings-hint">Token 需要账户级 Account Analytics: Read 权限，并授权对应账户；留空读取 Worker Secret。</p><button type="submit" className="primary-btn compact" disabled={busy}><Save size={14} />保存用量配置</button></div>
+                      <div className="usage-config-actions"><p className="settings-hint">Token 需要账户级 Account Analytics: Read 权限，并授权对应账户；留空读取 Worker Secret。</p><button type="submit" className="primary-btn compact" disabled={busy}><Save size={15} />保存用量配置</button></div>
                       {cloudflareUsage ? <><div className="usage-table-wrap"><table className="usage-table cloudflare-usage-table"><thead><tr><th>周期</th><th>D1 读取</th><th>D1 写入</th><th>Workers 请求</th><th>DO 请求（估算）</th><th>DO 时长 (GB-s)</th></tr></thead><tbody><UsageRow label="今日" usage={cloudflareUsage.today} /><UsageRow label="昨日" usage={cloudflareUsage.yesterday} /></tbody></table></div><div className="usage-do-breakdown"><UsageDoBreakdown label="今日" usage={cloudflareUsage.today} /><UsageDoBreakdown label="昨日" usage={cloudflareUsage.yesterday} /></div></> : <div className="usage-empty">尚未读取</div>}
                     </div>
                     <div className="data-actions"><button type="button" className="secondary-btn" onClick={() => void loadDatabase()}>刷新统计</button><button type="button" className="danger-btn" onClick={() => void clearHistory()}><Trash2 size={15} />清空历史指标</button></div>
                     <p className="settings-hint">清空历史不会删除节点、密钥或最新状态。</p>
                   </> : null}
 
-                  {tab !== "data" ? <div className="form-actions"><button className="primary-btn" disabled={busy}><Save size={16} />保存{tab === "security" ? "账号与安全设置" : "设置"}</button></div> : null}
+                  {tab !== "data" ? <div className="form-actions"><button className="primary-btn" disabled={busy}><Save size={15} />保存{tab === "security" ? "账号与安全设置" : "设置"}</button></div> : null}
                 </form>
               ) : tab === "about" ? (
                 <div className="admin-section about-page">
@@ -684,10 +691,10 @@ export function AdminPanel({
         <div className="form-grid three"><label><span>到期日期</span><input type="date" value={formatDate(form.expires_at)} onChange={(event) => updateForm("expires_at", event.target.value ? Math.floor(new Date(`${event.target.value}T00:00:00Z`).getTime() / 1000) : null)} /></label><label><span>Agent 上报间隔（秒）</span><input min="15" max="3600" type="number" value={form.report_interval} onChange={(event) => updateForm("report_interval", Number(event.target.value))} /></label><label><span>指标采样间隔（秒）</span><input min="1" max="60" type="number" value={form.collect_interval} onChange={(event) => updateForm("collect_interval", Number(event.target.value))} /></label></div>
         <div className="form-grid"><label><span>统计网卡（逗号分隔，留空自动）</span><input value={form.network_interface} onChange={(event) => updateForm("network_interface", event.target.value)} placeholder="eth0,ens3" /></label><label><span>下行流量当前值（GB）</span><input min="0" step="0.1" type="number" value={rxCurrentGb} onChange={(event) => setRxCurrentGb(event.target.value)} /></label><label><span>上行流量当前值（GB）</span><input min="0" step="0.1" type="number" value={txCurrentGb} onChange={(event) => setTxCurrentGb(event.target.value)} /></label><label><span>Agent 下载加速（可选）</span><input value={form.agent_mirror} onChange={(event) => updateForm("agent_mirror", event.target.value.trim())} placeholder="https://ghproxy.net" /></label></div>
         <div className="settings-toggles editor-toggles"><Toggle label="自动续费" checked={form.auto_renewal} onChange={(value) => updateForm("auto_renewal", value)} /><Toggle label="Agent 自动更新" checked={form.auto_update} onChange={(value) => updateForm("auto_update", value)} /><Toggle label="隐藏节点" checked={form.hidden} onChange={(value) => updateForm("hidden", value)} /><Toggle label="关闭离线告警" checked={form.offline_notify_disabled} onChange={(value) => updateForm("offline_notify_disabled", value)} /></div>
-        <div className="form-actions"><button type="button" className="secondary-btn" onClick={() => setEditing(null)}>取消</button><button className="primary-btn" disabled={busy}><Save size={16} />保存节点</button></div>
+        <div className="form-actions"><button type="button" className="secondary-btn" onClick={() => setEditing(null)}>取消</button><button className="primary-btn" disabled={busy}><Save size={15} />保存节点</button></div>
       </form></div> : null}
 
-      {installCommand ? <div className="submodal-backdrop" role="presentation" onMouseDown={installDialog.onBackdropMouseDown}><section ref={installDialog.dialogRef} className="install-modal glass-panel" role="dialog" aria-modal="true" aria-labelledby="install-dialog-title" tabIndex={-1}><header><div><span className="eyebrow">Agent 部署</span><h3 id="install-dialog-title">安装命令</h3></div><div className="segmented install-platform" aria-label="Agent 平台"><button type="button" className={installPlatform === "linux" ? "active" : ""} onClick={() => setInstallPlatform("linux")}>Linux</button><button type="button" className={installPlatform === "windows" ? "active" : ""} onClick={() => setInstallPlatform("windows")}>Windows</button><button type="button" className={installPlatform === "macos" ? "active" : ""} onClick={() => setInstallPlatform("macos")}>macOS ARM</button><button type="button" className={installPlatform === "freebsd" ? "active" : ""} onClick={() => setInstallPlatform("freebsd")}>FreeBSD</button></div></header><div className="install-list"><pre>{installCommand}</pre></div><div className="form-actions"><button className="secondary-btn" type="button" onClick={() => setInstall(null)}>关闭</button><button className="primary-btn" type="button" onClick={() => void copyInstallCommand()}><Copy size={16} />复制</button></div></section></div> : null}
+      {installCommand ? <div className="submodal-backdrop" role="presentation" onMouseDown={installDialog.onBackdropMouseDown}><section ref={installDialog.dialogRef} className="install-modal glass-panel" role="dialog" aria-modal="true" aria-labelledby="install-dialog-title" tabIndex={-1}><header><div><span className="eyebrow">Agent 部署</span><h3 id="install-dialog-title">安装命令</h3></div>{/* role="group" 是 aria-label 生效的前提，aria-pressed 表达选中态，理由同侧栏那处注释 */}<div className="segmented install-platform" role="group" aria-label="Agent 平台"><button type="button" className={installPlatform === "linux" ? "active" : ""} aria-pressed={installPlatform === "linux"} onClick={() => setInstallPlatform("linux")}>Linux</button><button type="button" className={installPlatform === "windows" ? "active" : ""} aria-pressed={installPlatform === "windows"} onClick={() => setInstallPlatform("windows")}>Windows</button><button type="button" className={installPlatform === "macos" ? "active" : ""} aria-pressed={installPlatform === "macos"} onClick={() => setInstallPlatform("macos")}>macOS ARM</button><button type="button" className={installPlatform === "freebsd" ? "active" : ""} aria-pressed={installPlatform === "freebsd"} onClick={() => setInstallPlatform("freebsd")}>FreeBSD</button></div></header><div className="install-list"><pre>{installCommand}</pre></div><div className="form-actions"><button className="secondary-btn" type="button" onClick={() => setInstall(null)}>关闭</button><button className="primary-btn" type="button" onClick={() => void copyInstallCommand()}><Copy size={15} />复制</button></div></section></div> : null}
     </div>
   );
 }
diff --git a/frontend/src/components/AlertRuleManager.tsx b/frontend/src/components/AlertRuleManager.tsx
index 879496c..85615e6 100644
--- a/frontend/src/components/AlertRuleManager.tsx
+++ b/frontend/src/components/AlertRuleManager.tsx
@@ -94,13 +94,13 @@ export function AlertRuleManager({ servers, onError, onNotice }: {
   const unit = form.metric === "net_in" || form.metric === "net_out" ? "MiB/s" : "%";
 
   return <div className="alert-rule-manager">
-    <div className="section-head"><div><h3>资源告警规则</h3><span>最多 20 条，可指定服务器和统计窗口</span></div><button type="button" className="primary-btn compact" onClick={() => open()}><Plus size={14} />新建规则</button></div>
+    <div className="section-head"><div><h3>资源告警规则</h3><span>最多 20 条，可指定服务器和统计窗口</span></div><button type="button" className="primary-btn compact" onClick={() => open()}><Plus size={15} />新建规则</button></div>
     <div className="alert-rule-list">
       {rules.map((rule) => <div className="alert-rule-row" key={rule.id}>
         <Checkbox checked={rule.enabled} onChange={() => void toggle(rule)} ariaLabel={`${rule.name}启用状态`} />
         <div><strong>{rule.name}</strong><small>{metricLabels[rule.metric]} ≥ {rule.threshold} {rule.metric.startsWith("net_") ? "MiB/s" : "%"} · {rule.duration_minutes} 分钟{rule.aggregation === "continuous" ? "持续" : "平均"} · {rule.server_ids.length ? `${rule.server_ids.length} 台服务器` : "全部服务器"}</small></div>
-        <button type="button" className="icon-btn" title="编辑规则" onClick={() => open(rule)}><Pencil size={14} /></button>
-        <button type="button" className="icon-btn danger" title="删除规则" onClick={() => void remove(rule)}><Trash2 size={14} /></button>
+        <button type="button" className="icon-btn" title="编辑规则" onClick={() => open(rule)}><Pencil size={15} /></button>
+        <button type="button" className="icon-btn danger" title="删除规则" onClick={() => void remove(rule)}><Trash2 size={15} /></button>
       </div>)}
       {!rules.length ? <div className="list-empty">尚未配置资源告警规则</div> : null}
     </div>
diff --git a/frontend/src/components/LatencyManager.tsx b/frontend/src/components/LatencyManager.tsx
index a2e1025..7f93a8b 100644
--- a/frontend/src/components/LatencyManager.tsx
+++ b/frontend/src/components/LatencyManager.tsx
@@ -136,7 +136,7 @@ export function LatencyManager({
   return <div className="admin-section latency-section">
     <div className="section-head">
       <div><h3>延迟任务</h3><span>{tasks.length} / 128 个任务 · TCP / ICMP</span></div>
-      <button className="primary-btn compact" type="button" disabled={tasks.length >= 128} onClick={() => open()}><Plus size={16} />添加</button>
+      <button className="primary-btn compact" type="button" disabled={tasks.length >= 128} onClick={() => open()}><Plus size={15} />添加</button>
     </div>
     <div className="latency-task-list">
       {tasks.map((task) => <div className="latency-task-row" key={task.id}>
@@ -164,7 +164,7 @@ export function LatencyManager({
         </div>
       </div>
       <label className="toggle-row"><span><b>默认分配给新服务器</b></span><Checkbox checked={form.default_enabled} onChange={(checked) => setForm((current) => ({ ...current, default_enabled: checked }))} /></label>
-      <div className="form-actions"><button type="button" className="secondary-btn" onClick={() => setEditing(null)}>取消</button><button className="primary-btn" disabled={busy}><Save size={16} />{busy ? "保存中" : "保存任务"}</button></div>
+      <div className="form-actions"><button type="button" className="secondary-btn" onClick={() => setEditing(null)}>取消</button><button className="primary-btn" disabled={busy}><Save size={15} />{busy ? "保存中" : "保存任务"}</button></div>
     </form></div> : null}
   </div>;
 }
diff --git a/frontend/src/components/NodeCard.tsx b/frontend/src/components/NodeCard.tsx
index 65e341e..8487d2a 100644
--- a/frontend/src/components/NodeCard.tsx
+++ b/frontend/src/components/NodeCard.tsx
@@ -62,8 +62,10 @@ function QualityPanel({ label, value, bars }: {
   value: string;
   bars: LatencyBar[];
 }) {
+  // 不挂 aria-label：label 和 value 已经是下面的可见文本，重复；
+  // 而且整张卡片是 <button>，role=button 的子树在无障碍树里会被整体裁掉，挂了也读不到。
   return (
-    <div className="quality-panel" aria-label={`${label} ${value}`}>
+    <div className="quality-panel">
       <div><span>{label}</span><b>{value}</b></div>
       <QualityBars bars={bars} />
     </div>
@@ -113,8 +115,11 @@ export function NodeCard({ server, config, onOpen }: { server: Server; config: C
     ? ui(locale, "加载中", "Loading")
     : ui(locale, "未匹配到线路", "No lines matched");
 
+  // 名字后面带上在线状态：卡片是 <button>，子树被裁掉，这个 aria-label 是读屏唯一能拿到的字符串。
+  // 状态在视觉上只由 status-dot 的颜色表达（WCAG 1.4.1 靠颜色传达信息），这里补成文字。
+  // 只放名字 + 状态，不塞 CPU/内存：一屏几十张卡，念完就太长了，数值留给详情页。
   return (
-    <button className={`node-card glass-panel ${online ? "" : "offline"}`} onClick={onOpen} type="button" aria-label={ui(locale, `查看 ${server.name} 详情`, `View ${server.name} details`)}>
+    <button className={`node-card glass-panel ${online ? "" : "offline"}`} onClick={onOpen} type="button" aria-label={ui(locale, `${server.name}，${online ? "在线" : "离线"}，查看详情`, `${server.name}, ${online ? "online" : "offline"}, view details`)}>
       <header className="node-header">
         <span className={`status-dot ${online ? "online" : ""}`} />
         <strong title={server.name}>{server.name}</strong>
@@ -137,16 +142,21 @@ export function NodeCard({ server, config, onOpen }: { server: Server; config: C
           <Metric label={ui(locale, "流量", "Traffic")} value={server.traffic_limit > 0 ? `${traffic.toFixed(1)}%` : "∞"} used={traffic} sub={`${formatBytes(usedTraffic)} / ${server.traffic_limit > 0 ? formatBytes(server.traffic_limit) : "∞"}`} muted={!online} valueTone={server.traffic_limit <= 0 ? "" : traffic >= 95 ? "danger-text" : traffic >= 60 ? "warning-text" : "success-text"} />
         </div>
 
+        {/* 这三个面板原来各挂一个 aria-label（实时速率 / 累计流量 / 剩余周期），全都没生效：
+            无 role 的 div 是 generic，规范禁止命名；就算补上 role="group"，整张卡片是 <button>，
+            role=button 的子树在无障碍树里会被整体裁掉，里面加什么都读不到。所以移除而不是修补。
+            读屏用户拿不到这些数值，真正的出路是把卡片从 <button> 改成内容 + 覆盖层按钮，
+            那是一次会动 CSS 和焦点行为的改造，没在这次一并做。 */}
         <div className={`data-grid ${showExpiryPanel ? "" : "two-columns"}`}>
-          <div className="data-panel" aria-label="实时速率">
+          <div className="data-panel">
             <CompactLine icon={<ChevronUp size={11} />} tone="success-text">{formatSpeed(server.net_out)}</CompactLine>
             <CompactLine icon={<ChevronDown size={11} />} tone="info-text">{formatSpeed(server.net_in)}</CompactLine>
           </div>
-          <div className="data-panel" aria-label="累计流量">
+          <div className="data-panel">
             <CompactLine icon={<Upload size={11} />}>{formatBytes(server.net_tx_total)}</CompactLine>
             <CompactLine icon={<Download size={11} />}>{formatBytes(server.net_rx_total)}</CompactLine>
           </div>
-          {showExpiryPanel ? <div className="data-panel" aria-label="剩余周期">
+          {showExpiryPanel ? <div className="data-panel">
             {config.show_expiry ? <CompactLine icon={<CalendarDays size={11} />}>{formatExpire(server, locale)}</CompactLine> : null}
             {config.show_price ? <CompactLine icon={<Coins size={11} />}>{server.price === -1
               ? ui(locale, "免费", "Free")
diff --git a/frontend/src/components/NodeDetails.tsx b/frontend/src/components/NodeDetails.tsx
index 56f5e5b..8907b6b 100644
--- a/frontend/src/components/NodeDetails.tsx
+++ b/frontend/src/components/NodeDetails.tsx
@@ -412,12 +412,16 @@ export function NodeDetails({ server, liveLatencyResults, threshold, retentionDa
 
       <section className="chart-section">
         <div className="chart-controls">
-          <div className="segmented" aria-label="图表类型">
-            <button className={chartType === "load" ? "active" : ""} onClick={() => setChartType("load")}><Activity size={14} />{ui(locale, "负载", "Load")}</button>
-            {pingEnabled ? <button className={chartType === "latency" ? "active" : ""} onClick={() => setChartType("latency")}><RadioTower size={14} />{ui(locale, "延迟", "Latency")}</button> : null}
+          {/* role="group" 是让 aria-label 生效的前提：无 role 的 div 是 generic，
+              规范禁止给它命名，浏览器会把 aria-label 丢掉。下面几处同理。
+              选中态用 aria-pressed 而不是 role="radio"：radio 组要求方向键 + roving tabindex，
+              这里保持 Tab 逐个走的现状。同文件延迟任务图例用的也是 aria-pressed。 */}
+          <div className="segmented" role="group" aria-label={ui(locale, "图表类型", "Chart type")}>
+            <button className={chartType === "load" ? "active" : ""} aria-pressed={chartType === "load"} onClick={() => setChartType("load")}><Activity size={14} />{ui(locale, "负载", "Load")}</button>
+            {pingEnabled ? <button className={chartType === "latency" ? "active" : ""} aria-pressed={chartType === "latency"} onClick={() => setChartType("latency")}><RadioTower size={14} />{ui(locale, "延迟", "Latency")}</button> : null}
           </div>
-          <div className="segmented range-control" aria-label="时间范围">
-            {ranges.map((range) => <button className={hours === range.value ? "active" : ""} key={range.value} onClick={() => chartType === "load" ? setLoadHours(range.value) : setLatencyHours(range.value)}>{range.label}</button>)}
+          <div className="segmented range-control" role="group" aria-label={ui(locale, "时间范围", "Time range")}>
+            {ranges.map((range) => <button className={hours === range.value ? "active" : ""} aria-pressed={hours === range.value} key={range.value} onClick={() => chartType === "load" ? setLoadHours(range.value) : setLatencyHours(range.value)}>{range.label}</button>)}
           </div>
         </div>
 
@@ -447,7 +451,7 @@ export function NodeDetails({ server, liveLatencyResults, threshold, retentionDa
                 <small>{series.loss == null ? "--" : `${series.loss.toFixed(2)}%`} 平均丢包</small>
               </div>)}
             </div>
-            <div className="latency-task-legend" aria-label={ui(locale, "延迟任务", "Latency tasks")}>
+            <div className="latency-task-legend" role="group" aria-label={ui(locale, "延迟任务", "Latency tasks")}>
               {latencySeries.map((series) => {
                 const hidden = hiddenLatencyTaskIds.has(series.id);
                 return <button
diff --git a/frontend/src/components/ProgressBar.tsx b/frontend/src/components/ProgressBar.tsx
index 56a5d8b..4b781c8 100644
--- a/frontend/src/components/ProgressBar.tsx
+++ b/frontend/src/components/ProgressBar.tsx
@@ -1,8 +1,11 @@
 export function ProgressBar({ value }: { value: number }) {
   const safe = Math.min(100, Math.max(0, value || 0));
   const status = safe >= 90 ? "danger" : safe >= 70 ? "warning" : "good";
+  // 纯装饰：调用方 Metric 已经把同一个百分比作为可见文本渲染在旁边，再报一遍是重复。
+  // aria-hidden 明说它不进无障碍树。原来这里挂 aria-label，但无 role 的 span 是 generic，
+  // 规范禁止给它命名，那个标签从来没生效过。
   return (
-    <span className="progress-track" aria-label={`${safe.toFixed(1)}%`}>
+    <span className="progress-track" aria-hidden="true">
       <span className={`progress-fill ${status}`} style={{ width: `${safe}%` }} />
     </span>
   );
diff --git a/frontend/src/styles/admin.css b/frontend/src/styles/admin.css
index 6599a45..091cde4 100644
--- a/frontend/src/styles/admin.css
+++ b/frontend/src/styles/admin.css
@@ -5,17 +5,22 @@
 .modal-backdrop, .submodal-backdrop { position: fixed; z-index: 80; inset: 0; display: flex; align-items: center; justify-content: center; padding: 24px; background: rgb(5 10 12 / .56); backdrop-filter: blur(6px); }
 .submodal-backdrop { z-index: 90; background: rgb(5 10 12 / .42); }
 
+/* 两处色值受无障碍下限约束，改动前先算比值：
+   --admin-border-strong 是 input/select/textarea/secondary-btn/checkbox 的边界，
+   而这些控件的背景和容器同为 --admin-surface，边框是唯一可辨识的轮廓，
+   受 WCAG 1.4.11 约束需 >= 3:1（装饰性的 --admin-border 不受此约束）。
+   --admin-accent 会落在 --admin-active-bg 上当选中态文字，需 >= 4.5:1。 */
 .admin-page, .admin-loading {
   --admin-bg: #f4f6f8;
   --admin-surface: #fff;
   --admin-text: #111827;
   --admin-muted: #4b5563;
   --admin-border: #d9dee5;
-  --admin-border-strong: #c7ced8;
+  --admin-border-strong: #8592a6; /* 白底 3.15:1 */
   --admin-border-hover: #aeb8c5;
   --admin-hover: #eef1f5;
   --admin-active-bg: #e3f3ef;
-  --admin-accent: #0d7d6f;
+  --admin-accent: #0c7367; /* 选中底 5.00:1，白底 5.73:1 */
   --admin-accent-border: #0a6e61;
 }
 .admin-page.admin-dark, .admin-loading.admin-dark {
@@ -24,7 +29,7 @@
   --admin-text: #f3f4f6;
   --admin-muted: #b9c0c7;
   --admin-border: #343b40;
-  --admin-border-strong: #485159;
+  --admin-border-strong: #616d78; /* 卡片底 3.11:1 */
   --admin-border-hover: #65717b;
   --admin-hover: #242b2d;
   --admin-active-bg: #173830;
@@ -40,6 +45,9 @@
 .admin-page label > span { color: var(--admin-text); font-size: 13px; font-weight: 600; }
 .admin-page .icon-btn { color: var(--admin-muted); }
 .admin-page .icon-btn:hover { color: var(--admin-text); background: var(--admin-hover); }
+/* 后台按钮里的图标统一尺寸。lucide 的 size 渲染成 width/height 属性，
+   CSS 在层叠里压过表现属性，所以这条说了算 —— JSX 的 size 必须和这里一致，
+   否则代码里的数字是假的。改这里也要改对应的 size。 */
 .admin-page button svg { width: 15px; height: 15px; }
 .admin-page .primary-btn, .admin-page .secondary-btn, .admin-page .danger-btn { min-height: 36px; font-size: 13px; }
 .primary-btn.compact { min-height: 34px; padding: 6px 11px; }
@@ -62,6 +70,9 @@
 .login-turnstile { display: flex; min-height: 66px; justify-content: center; }
 .login-turnstile:has(.turnstile-widget.testing) { min-height: 51px; }
 .login-turnstile:has(.turnstile-widget.verified) { min-height: 0; }
+/* 登录错误就近显示，不用右上角的 toast —— 那个的 top 是按后台顶栏算的 */
+.login-error { display: flex; align-items: flex-start; gap: 7px; margin: 0; border: 1px solid color-mix(in srgb, var(--danger) 34%, var(--admin-border)); border-radius: 7px; padding: 9px 11px; color: var(--danger); background: color-mix(in srgb, var(--danger) 7%, transparent); font-size: 13px; line-height: 1.5; }
+.login-error svg { flex: 0 0 auto; margin-top: 1px; }
 .login-submit { width: 100%; min-height: 40px; }
 .eyebrow { display: block; margin-bottom: 3px; color: var(--admin-accent); font-size: 11px; font-weight: 750; text-transform: uppercase; }
 
@@ -78,7 +89,7 @@
 .admin-nav-label { display: block; margin: 0 11px 8px; color: var(--admin-muted); font-size: 12px; font-weight: 700; }
 .admin-tabs { display: flex; flex-direction: column; gap: 5px; border: 0; padding: 0; }
 .admin-tabs button { display: flex; min-height: 44px; align-items: center; gap: 9px; border-radius: 6px; padding: 0 12px; color: var(--admin-text); font-size: 14px; font-weight: 600; text-align: left; }
-.admin-tabs button svg { width: 17px; height: 17px; }
+.admin-tabs button svg { width: 17px; height: 17px; } /* 覆盖上面的 15px，见该处注释 */
 .admin-tabs button:hover { background: var(--admin-hover); }
 .admin-tabs button.active { border-left: 3px solid var(--admin-accent-border); padding-left: 9px; color: var(--admin-accent); background: var(--admin-active-bg); font-weight: 700; }
 .admin-content { width: 100%; max-width: 100%; height: 100%; min-width: 0; overflow-y: auto; color: var(--admin-text); background: var(--admin-bg); }
@@ -244,36 +255,8 @@
   .telegram-token-field { grid-column: 1 / -1; }
 }
 
-@media (max-width: 639px) {
-  .modal-backdrop, .submodal-backdrop { align-items: stretch; padding: 0; }
-  .admin-shell, .editor-modal, .install-modal, .latency-editor { width: 100%; max-height: 100dvh; border: 0; border-radius: 0; }
-  .admin-shell { height: 100dvh; min-height: 100dvh; }
-  .admin-back { top: 12px; left: 12px; }
-  .login-form { width: calc(100% - 26px); padding: 24px 20px; }
-  .admin-body { display: flex; height: calc(100vh - 62px); min-height: 0; flex-direction: column; }
-  .admin-tabs { overflow-x: auto; flex-direction: row; border-right: 0; border-bottom: 1px solid var(--admin-border); padding: 7px 10px; }
-  .admin-tabs button { min-height: 33px; flex: 0 0 auto; }
-  .admin-content { height: calc(100vh - 112px); }
-  .admin-section, .settings-form { padding: 14px; }
-  .section-head { align-items: flex-start; }
-  .server-row { padding-block: 6px; grid-template-columns: 18px 20px 9px minmax(0, 1fr) auto; }
-  .form-grid, .form-grid.three, .settings-toggles, .theme-option-grid { grid-template-columns: 1fr; }
-  .theme-row { grid-template-columns: minmax(0, 1fr); }
-  .theme-row-actions { justify-content: flex-start; }
-  .data-stat-grid { grid-template-columns: 1fr 1fr 1fr; }
-  .usage-do-breakdown { grid-template-columns: 1fr; }
-  .usage-table th, .usage-table td { padding-inline: 5px; font-size: 11px; }
-  .editor-modal, .install-modal { padding: 15px 13px; }
-  .telegram-fields { grid-template-columns: 1fr; }
-  .telegram-token-field { grid-column: auto; }
-  .editor-toggles { grid-template-columns: 1fr 1fr; }
-  .latency-task-row { padding-block: 8px; grid-template-columns: 70px minmax(0, 1fr) auto; }
-  .latency-task-row .latency-task-meta:nth-of-type(2) { display: none; }
-  .latency-task-row .latency-task-meta:nth-of-type(3) { grid-column: 2; }
-  .latency-task-row .row-actions { grid-column: 3; grid-row: 1 / 3; }
-  .latency-editor { padding: 15px 13px; }
-}
-
+/* 断点顺序必须由宽到窄：760 和 639 都命中窄屏且特异性相同，写在后面的赢。
+   639 块只保留在 760 之上的收窄项，重复或已被 760 取代的声明都删掉了。 */
 @media (max-width: 760px) {
   .admin-shell { grid-template-rows: 58px minmax(0, 1fr); }
   .admin-topbar { gap: 10px; padding: 0 12px; }
@@ -303,6 +286,29 @@
   .admin-login-theme { top: 12px; right: 12px; }
 }
 
+@media (max-width: 639px) {
+  .modal-backdrop, .submodal-backdrop { align-items: stretch; padding: 0; }
+  .admin-shell, .editor-modal, .install-modal, .latency-editor { width: 100%; max-height: 100dvh; border: 0; border-radius: 0; }
+  .admin-shell { min-height: 100dvh; }
+  .login-form { width: calc(100% - 26px); padding: 24px 20px; }
+  .admin-section, .settings-form { padding: 14px; }
+  .server-row { padding-block: 6px; grid-template-columns: 18px 20px 9px minmax(0, 1fr) auto; }
+  .form-grid, .form-grid.three, .settings-toggles, .theme-option-grid { grid-template-columns: 1fr; }
+  /* 与 .settings-toggles 同元素，撤销上一行的单列 */
+  .editor-toggles { grid-template-columns: 1fr 1fr; }
+  .theme-row { grid-template-columns: minmax(0, 1fr); }
+  .theme-row-actions { justify-content: flex-start; }
+  .usage-do-breakdown { grid-template-columns: 1fr; }
+  .usage-table th, .usage-table td { padding-inline: 5px; font-size: 11px; }
+  .editor-modal, .install-modal, .latency-editor { padding: 15px 13px; }
+  .telegram-fields { grid-template-columns: 1fr; }
+  .telegram-token-field { grid-column: auto; }
+  .latency-task-row { padding-block: 8px; grid-template-columns: 70px minmax(0, 1fr) auto; }
+  .latency-task-row .latency-task-meta:nth-of-type(2) { display: none; }
+  .latency-task-row .latency-task-meta:nth-of-type(3) { grid-column: 2; }
+  .latency-task-row .row-actions { grid-column: 3; grid-row: 1 / 3; }
+}
+
 .server-name-main { display: flex; min-width: 0; align-items: center; gap: 7px; }
 .server-name-main .region-flag { flex: 0 0 auto; font-size: 16px; line-height: 1; }
 .server-name-main strong { overflow: hidden; font-size: 14px; text-overflow: ellipsis; white-space: nowrap; }
diff --git a/migrations/initial_01.sql b/migrations/initial_01.sql
index a3de615..22d16de 100644
--- a/migrations/initial_01.sql
+++ b/migrations/initial_01.sql
@@ -71,7 +71,6 @@ CREATE TABLE metric_history (
   disk_utilization REAL NOT NULL DEFAULT 0,
   sample_count INTEGER NOT NULL DEFAULT 1 CHECK(sample_count > 0),
   latest_timestamp INTEGER NOT NULL,
-  latest_json TEXT NOT NULL CHECK(json_valid(latest_json)),
   latency_json TEXT NOT NULL DEFAULT '[]' CHECK(json_valid(latency_json)),
   PRIMARY KEY(server_id, timestamp)
 ) WITHOUT ROWID;
@@ -109,7 +108,6 @@ CREATE TABLE metric_history_old (
   disk_utilization REAL NOT NULL DEFAULT 0,
   sample_count INTEGER NOT NULL DEFAULT 1 CHECK(sample_count > 0),
   latest_timestamp INTEGER NOT NULL,
-  latest_json TEXT NOT NULL CHECK(json_valid(latest_json)),
   latency_json TEXT NOT NULL DEFAULT '[]' CHECK(json_valid(latency_json)),
   PRIMARY KEY(server_id, timestamp)
 ) WITHOUT ROWID;
@@ -144,7 +142,6 @@ CREATE TABLE metric_history_hourly (
   disk_utilization REAL NOT NULL DEFAULT 0,
   sample_count INTEGER NOT NULL DEFAULT 1 CHECK(sample_count > 0),
   latest_timestamp INTEGER NOT NULL,
-  latest_json TEXT NOT NULL CHECK(json_valid(latest_json)),
   latency_json TEXT NOT NULL DEFAULT '[]' CHECK(json_valid(latency_json)),
   PRIMARY KEY(server_id, timestamp)
 ) WITHOUT ROWID;
diff --git a/scripts/websocket-smoke.mjs b/scripts/websocket-smoke.mjs
index 0d7366a..ab8fac4 100644
--- a/scripts/websocket-smoke.mjs
+++ b/scripts/websocket-smoke.mjs
@@ -284,7 +284,7 @@ try {
       ),
   );
   agent.send(JSON.stringify({ type: "update", batchId: `smoke-${timestamp}`, samples }));
-  const [ack] = await Promise.all([ackPromise, updatePromise]);
+  const [ack, update] = await Promise.all([ackPromise, updatePromise]);
   if (
     ack.ts <= 0 ||
     ack.persisted !== true ||
@@ -296,6 +296,37 @@ try {
   ) {
     throw new Error(`Invalid Agent metric ACK: ${JSON.stringify(ack)}`);
   }
+
+  // 身份字段不该出现在发往浏览器的样本里（Worker 侧剥离），但必须仍能从
+  // bootstrap 拿到 —— 前端靠 { ...server, ...live.metrics } 的覆盖顺序兜底。
+  // fixture 里 gpu_model="NVIDIA T4"、agent_version="smoke" 都是非空的。
+  const omitted = [
+    "cpu_model",
+    "os",
+    "kernel",
+    "arch",
+    "virtualization",
+    "gpu_model",
+    "agent_version",
+  ];
+  for (const entry of update.updates.flatMap((u) => u.samples ?? [])) {
+    const leaked = omitted.filter((field) => entry.data?.[field] !== undefined);
+    if (leaked.length) {
+      throw new Error(`Live sample leaked identity fields: ${leaked.join(", ")}`);
+    }
+    if (entry.data?.cpu === undefined) {
+      throw new Error("Live sample lost a dynamic field (cpu)");
+    }
+  }
+  const bootstrap = await fetch(new URL("/api/bootstrap", baseUrl)).then((r) => r.json());
+  const persisted = bootstrap.servers?.find((s) => s.id === serverId);
+  if (!persisted) {
+    throw new Error(`Bootstrap missing server ${serverId}`);
+  }
+  const missing = omitted.filter((field) => !persisted[field]);
+  if (missing.length) {
+    throw new Error(`Bootstrap missing identity fields: ${missing.join(", ")}`);
+  }
   }
 } finally {
   await Promise.all([
diff --git a/src/db.rs b/src/db.rs
index 8da4e99..2a76acf 100644
--- a/src/db.rs
+++ b/src/db.rs
@@ -60,7 +60,6 @@ pub(crate) fn metric_history_ddl(table: &str) -> String {
   disk_utilization REAL NOT NULL DEFAULT 0,
   sample_count INTEGER NOT NULL DEFAULT 1 CHECK(sample_count > 0),
   latest_timestamp INTEGER NOT NULL,
-  latest_json TEXT NOT NULL CHECK(json_valid(latest_json)),
   latency_json TEXT NOT NULL DEFAULT '[]' CHECK(json_valid(latency_json)),
   PRIMARY KEY(server_id, timestamp)
 ) WITHOUT ROWID"#
@@ -1028,14 +1027,14 @@ pub async fn save_reports_with_history(
           tcp_connections, udp_connections, gpu_usage,
           disk_read_bps, disk_write_bps, disk_read_iops, disk_write_iops,
           disk_await_ms, disk_utilization, sample_count,
-          latest_timestamp, latest_json, latency_json
+          latest_timestamp, latency_json
         ) SELECT
           ?1, ?2, ?3, ?4, ?5, ?6, ?7, ?8, ?9, ?10, ?11, ?12, ?13, ?14,
           ?15, ?16, ?17, ?18, ?19, ?20, ?21, ?22, ?23, ?24, ?25, ?26,
-          ?27, ?28, ?29, ?30
+          ?27, ?28, ?29
         WHERE NOT EXISTS (
           SELECT 1 FROM server_latest_state
-          WHERE server_id = ?1 AND last_batch_id = ?31
+          WHERE server_id = ?1 AND last_batch_id = ?30
         ) ON CONFLICT(server_id, timestamp) DO UPDATE SET
           cpu=(metric_history.cpu * metric_history.sample_count +
             excluded.cpu * excluded.sample_count) /
@@ -1074,9 +1073,6 @@ pub async fn save_reports_with_history(
           disk_utilization=MAX(metric_history.disk_utilization, excluded.disk_utilization),
           sample_count=metric_history.sample_count + excluded.sample_count,
           latest_timestamp=MAX(metric_history.latest_timestamp, excluded.latest_timestamp),
-          latest_json=CASE
-            WHEN excluded.latest_timestamp >= metric_history.latest_timestamp THEN excluded.latest_json
-            ELSE metric_history.latest_json END,
           latency_json=CASE
             WHEN json_array_length(excluded.latency_json) = 0 THEN metric_history.latency_json
             ELSE (
@@ -1161,7 +1157,6 @@ pub async fn save_reports_with_history(
         number(history_point.disk_utilization),
         number(sample_count.max(1)),
         number(latest_timestamp),
-        text(&latest_json),
         text(&latency_json),
         text(batch_id),
     ])?;
@@ -1657,14 +1652,14 @@ pub async fn cleanup_history(db: &D1Database, retention_days: i64) -> Result<()>
           net_rx_total, net_tx_total, processes, tcp_connections, udp_connections,
           gpu_usage, disk_read_bps, disk_write_bps, disk_read_iops, disk_write_iops,
           disk_await_ms, disk_utilization, sample_count,
-          latest_timestamp, latest_json, latency_json
+          latest_timestamp, latency_json
         ) SELECT
           m.server_id, m.bucket, m.cpu, m.load1, m.load5, m.load15, m.mem_used,
           m.mem_total, m.swap_used, m.swap_total, m.disk_used, m.disk_total,
           m.net_in, m.net_out, m.net_rx_total, m.net_tx_total, m.processes,
           m.tcp_connections, m.udp_connections, m.gpu_usage, m.disk_read_bps,
           m.disk_write_bps, m.disk_read_iops, m.disk_write_iops, m.disk_await_ms,
-          m.disk_utilization, m.sample_count, m.latest_timestamp, '{}',
+          m.disk_utilization, m.sample_count, m.latest_timestamp,
           COALESCE(l.latency_json, '[]')
         FROM metrics m LEFT JOIN latency_packed l
           ON l.server_id = m.server_id AND l.bucket = m.bucket
@@ -1693,7 +1688,6 @@ pub async fn cleanup_history(db: &D1Database, retention_days: i64) -> Result<()>
           disk_utilization=excluded.disk_utilization,
           sample_count=excluded.sample_count,
           latest_timestamp=excluded.latest_timestamp,
-          latest_json=excluded.latest_json,
           latency_json=excluded.latency_json"#,
         )
         .bind(&[number(cutoff), number(complete_hours_before)])?;
diff --git a/src/live.rs b/src/live.rs
index 9eb2f28..2588af4 100644
--- a/src/live.rs
+++ b/src/live.rs
@@ -28,6 +28,25 @@ const MAX_ALERT_WINDOW_SAMPLES: usize = 24 * 60 + 1;
 const ALERT_STORAGE_PREFIX: &str = "resource-alert:";
 const DASHBOARD_HUB_NAME: &str = "dashboard";
 
+/// 机器身份字段，一批里逐条重复且几乎不变，实时样本不带它们。
+///
+/// 前端 `mergeServerLive` 是 `{ ...server, ...live.metrics }`，样本里缺的键会露出
+/// bootstrap 那份，而 `SERVER_SELECT` 从 `server_latest_state.latest_json` 里
+/// `json_extract` 出这七个字段，所以前端不需要任何改动。
+///
+/// 代价：agent 升级后这些值要等下一次 bootstrap 轮询才刷新。
+/// 只影响展示，不影响任何判定 —— 告警和持久化读的是 `AgentReport` 本身，
+/// 剥离只发生在发往浏览器的副本上。
+const BROWSER_OMITTED_REPORT_FIELDS: [&str; 7] = [
+    "cpu_model",
+    "os",
+    "kernel",
+    "arch",
+    "virtualization",
+    "gpu_model",
+    "agent_version",
+];
+
 fn server_hub_name(server_id: &str) -> String {
     format!("server:{server_id}")
 }
@@ -427,6 +446,9 @@ fn batch_update_parts_at(
         let mut data = serde_json::to_value(report)?;
         if let Some(data) = data.as_object_mut() {
             data.remove("timestamp");
+            for key in BROWSER_OMITTED_REPORT_FIELDS {
+                data.remove(key);
+            }
         }
         samples.push(CachedLiveSample {
             ts: timestamp,
@@ -1382,9 +1404,10 @@ mod tests {
         consume_agent_message_budget, finish_d1_flush, live_ack_payload, next_d1_write_ms,
         outbound_close_code, trim_cached_live_samples, trim_socket_attachment, update_alert_window,
         AgentMessageBudget, AlertEvaluationServer, AlertWindowSample, CachedLiveSample,
-        SocketAttachment, TrafficAttachment, ALERT_WINDOW_SECONDS, CACHED_LIVE_TTL_SECONDS,
-        MAX_AGENT_BYTES_PER_WINDOW, MAX_AGENT_MESSAGES_PER_WINDOW, MAX_AGENT_SAMPLES_PER_WINDOW,
-        MAX_CACHED_LIVE_BYTES, MAX_CACHED_LIVE_SAMPLES, MAX_SERIALIZED_ATTACHMENT_BYTES,
+        SocketAttachment, TrafficAttachment, ALERT_WINDOW_SECONDS, BROWSER_OMITTED_REPORT_FIELDS,
+        CACHED_LIVE_TTL_SECONDS, MAX_AGENT_BYTES_PER_WINDOW, MAX_AGENT_MESSAGES_PER_WINDOW,
+        MAX_AGENT_SAMPLES_PER_WINDOW, MAX_CACHED_LIVE_BYTES, MAX_CACHED_LIVE_SAMPLES,
+        MAX_SERIALIZED_ATTACHMENT_BYTES,
     };
     use crate::db::HistoryMetricAggregate;
     use crate::latency::LatencyMetricAggregates;
@@ -1510,6 +1533,32 @@ mod tests {
         assert!(payload["updates"][0]["samples"][0]["data"]
             .get("timestamp")
             .is_none());
+        // 身份字段不上线：前端靠 bootstrap 那份。fixture 里 cpu_model="CPU"、
+        // agent_version="test" 都是非空的，所以这几条断言不是空转。
+        for field in BROWSER_OMITTED_REPORT_FIELDS {
+            assert!(
+                payload["updates"][0]["samples"][0]["data"]
+                    .get(field)
+                    .is_none(),
+                "{field} 不应出现在发往浏览器的样本里"
+            );
+        }
+        // 同一批的动态字段必须留着，别把剥离范围扩大了
+        for field in [
+            "cpu",
+            "mem_used",
+            "net_in",
+            "uptime",
+            "cpu_cores",
+            "gpu_usage",
+        ] {
+            assert!(
+                payload["updates"][0]["samples"][0]["data"]
+                    .get(field)
+                    .is_some(),
+                "{field} 是动态字段，不该被剥离"
+            );
+        }
         let attachment = SocketAttachment {
             role: "agent".to_string(),
             server_id: Some("node-a".to_string()),