diff --git a/frontend/src/App.vue b/frontend/src/App.vue
index 1cd0a0c..53f54f1 100644
--- a/frontend/src/App.vue
+++ b/frontend/src/App.vue
@@ -1,12 +1,17 @@
 <script setup lang="ts">
+import { computed } from 'vue'
 import { RouterLink, RouterView } from 'vue-router'
 
-const navItems = [
-  { to: '/', label: '总览' },
-  { to: '/video', label: '视频流' },
-  { to: '/map', label: '地图定位' },
-  { to: '/network', label: '网络状态' },
-]
+import { useLocale } from '@/lib/locale'
+
+const { t, toggleLocale, nextLocaleLabel } = useLocale()
+
+const navItems = computed(() => [
+  { to: '/', label: t('app.nav.overview') },
+  { to: '/video', label: t('app.nav.video') },
+  { to: '/map', label: t('app.nav.map') },
+  { to: '/network', label: t('app.nav.network') },
+])
 </script>
 
 <template>
@@ -15,21 +20,27 @@ const navItems = [
       <div class="brand">
         <p class="brand-mark">RCC</p>
         <div>
-          <strong>Robot Command Center</strong>
-          <span>机器人竞赛指挥台</span>
+          <strong>{{ t('app.brandTitle') }}</strong>
+          <span>{{ t('app.brandSubtitle') }}</span>
         </div>
       </div>
 
-      <nav class="nav">
-        <RouterLink
-          v-for="item in navItems"
-          :key="item.to"
-          :to="item.to"
-          class="nav-link"
-        >
-          {{ item.label }}
-        </RouterLink>
-      </nav>
+      <div class="topbar-actions">
+        <nav class="nav">
+          <RouterLink
+            v-for="item in navItems"
+            :key="item.to"
+            :to="item.to"
+            class="nav-link"
+          >
+            {{ item.label }}
+          </RouterLink>
+        </nav>
+
+        <button type="button" class="locale-button" @click="toggleLocale">
+          {{ nextLocaleLabel }}
+        </button>
+      </div>
     </header>
 
     <main class="page-body">
@@ -128,6 +139,14 @@ const navItems = [
   font-size: 13px;
 }
 
+.topbar-actions {
+  display: flex;
+  align-items: center;
+  gap: 12px;
+  flex-wrap: wrap;
+  justify-content: flex-end;
+}
+
 .nav {
   display: flex;
   gap: 10px;
@@ -135,7 +154,8 @@ const navItems = [
   justify-content: flex-end;
 }
 
-.nav-link {
+.nav-link,
+.locale-button {
   padding: 10px 14px;
   border-radius: 999px;
   border: 1px solid rgba(133, 147, 169, 0.18);
@@ -148,7 +168,8 @@ const navItems = [
     border-color 0.2s ease;
 }
 
-.nav-link:hover {
+.nav-link:hover,
+.locale-button:hover {
   transform: translateY(-1px);
   background: rgba(25, 38, 66, 0.9);
 }
@@ -160,6 +181,13 @@ const navItems = [
   font-weight: 700;
 }
 
+.locale-button {
+  cursor: pointer;
+  font: inherit;
+  font-weight: 700;
+  white-space: nowrap;
+}
+
 .page-body {
   display: grid;
 }
@@ -170,6 +198,7 @@ const navItems = [
     align-items: stretch;
   }
 
+  .topbar-actions,
   .nav {
     justify-content: flex-start;
   }
@@ -180,6 +209,7 @@ const navItems = [
     width: min(100%, calc(100% - 20px));
   }
 
+  .topbar-actions,
   .nav {
     display: grid;
     grid-template-columns: 1fr;
diff --git a/frontend/src/components/ControlFeedback.vue b/frontend/src/components/ControlFeedback.vue
index 6a2526a..326a11f 100644
--- a/frontend/src/components/ControlFeedback.vue
+++ b/frontend/src/components/ControlFeedback.vue
@@ -2,6 +2,7 @@
 import { computed } from 'vue'
 
 import { useControlInterface } from '@/composables/useControlInterface'
+import { t } from '@/lib/locale'
 
 const props = withDefaults(defineProps<{
   compact?: boolean
@@ -51,22 +52,43 @@ const keyClusters = computed(() => {
 
 const commandBars = computed(() => [
   {
-    label: 'Forward',
+    label: t('controlFeedback.forward'),
     value: commandValues.value.lx,
     max: controlLimits.value.forward,
   },
   {
-    label: 'Strafe',
+    label: t('controlFeedback.strafe'),
     value: commandValues.value.ly,
     max: controlLimits.value.strafe,
   },
   {
-    label: 'Turn',
+    label: t('controlFeedback.turn'),
     value: commandValues.value.az,
     max: controlLimits.value.turn,
   },
 ])
 
+const tuningSummary = computed(() =>
+  t('controlFeedback.tuningSummary', {
+    forward: controlTuning.value.forward.toFixed(2),
+    strafe: controlTuning.value.strafe.toFixed(2),
+    turn: controlTuning.value.turn.toFixed(2),
+    turbo: controlTuning.value.turbo.toFixed(2),
+  }),
+)
+
+const gamepadMeta = computed(() => {
+  if (!gamepadConnected.value) {
+    return t('controlFeedback.gamepadHint')
+  }
+  return t('controlFeedback.gamepadMeta', {
+    index: gamepadIndex.value ?? '--',
+    mapping: gamepadMapping.value || t('control.gamepad.unknownMapping'),
+  })
+})
+
+const outgoingCommandText = computed(() => t('controlFeedback.outgoingCommand', { command: commandLabel.value }))
+
 function meterPosition(value: number, max: number) {
   const normalized = Math.max(-1, Math.min(1, value / max))
   return `${50 + normalized * 45}%`
@@ -85,7 +107,7 @@ function stickOffset(value: number) {
           {{ activeSourceLabel }}
         </div>
         <div class="input-chip">
-          {{ controlInputModeLabel }} mode
+          {{ t('controlFeedback.modeChip', { mode: controlInputModeLabel }) }}
         </div>
       </div>
       <div class="status-stack">
@@ -112,19 +134,18 @@ function stickOffset(value: number) {
     </div>
 
     <p class="summary">
-      Tuning: fwd {{ controlTuning.forward.toFixed(2) }} m/s, strafe {{ controlTuning.strafe.toFixed(2) }} m/s,
-      turn {{ controlTuning.turn.toFixed(2) }} rad/s, turbo x{{ controlTuning.turbo.toFixed(2) }}
+      {{ tuningSummary }}
     </p>
 
     <div class="feedback-grid" :class="{ compact }">
       <section class="feedback-card">
         <div class="card-head">
           <div>
-            <p class="label">Keyboard</p>
+            <p class="label">{{ t('controlFeedback.keyboard') }}</p>
             <strong>{{ pressedKeysLabel }}</strong>
           </div>
           <span class="mode-chip" :class="{ hot: controlInputMode === 'keyboard' && keyboardActive }">
-            {{ controlInputMode === 'keyboard' ? (keyboardTurbo ? 'Turbo' : 'Selected') : 'Standby' }}
+            {{ controlInputMode === 'keyboard' ? (keyboardTurbo ? t('common.turbo') : t('common.selected')) : t('common.standby') }}
           </span>
         </div>
 
@@ -143,31 +164,27 @@ function stickOffset(value: number) {
       <section class="feedback-card">
         <div class="card-head">
           <div>
-            <p class="label">Gamepad</p>
-            <strong>{{ gamepadConnected ? gamepadName : 'Waiting for controller' }}</strong>
+            <p class="label">{{ t('controlFeedback.gamepad') }}</p>
+            <strong>{{ gamepadConnected ? gamepadName : t('controlFeedback.waitingForController') }}</strong>
           </div>
           <span class="mode-chip" :class="{ hot: controlInputMode === 'gamepad' && gamepadActive }">
             {{
               gamepadConnected
                 ? controlInputMode === 'gamepad'
-                  ? 'Selected'
-                  : 'Standby'
-                : 'Offline'
+                  ? t('common.selected')
+                  : t('common.standby')
+                : t('common.offline')
             }}
           </span>
         </div>
 
         <p class="subtle">
-          {{
-            gamepadConnected
-              ? `#${gamepadIndex} / mapping=${gamepadMapping || 'unknown'}`
-              : 'Left stick drives, right stick turns, RB boosts, A stops.'
-          }}
+          {{ gamepadMeta }}
         </p>
 
         <div class="sticks">
           <div class="stick-card">
-            <span>Left stick</span>
+            <span>{{ t('controlFeedback.leftStick') }}</span>
             <div class="stick-pad">
               <span class="crosshair crosshair-x" />
               <span class="crosshair crosshair-y" />
@@ -181,7 +198,7 @@ function stickOffset(value: number) {
           </div>
 
           <div class="stick-card">
-            <span>Right stick</span>
+            <span>{{ t('controlFeedback.rightStick') }}</span>
             <div class="stick-pad">
               <span class="crosshair crosshair-x" />
               <span class="crosshair crosshair-y" />
@@ -209,7 +226,7 @@ function stickOffset(value: number) {
     </div>
 
     <p v-if="!compact" class="summary accent">
-      Outgoing command: {{ commandLabel }}
+      {{ outgoingCommandText }}
     </p>
   </section>
 </template>
diff --git a/frontend/src/components/ControlPanel.vue b/frontend/src/components/ControlPanel.vue
index b15e646..318455e 100644
--- a/frontend/src/components/ControlPanel.vue
+++ b/frontend/src/components/ControlPanel.vue
@@ -3,14 +3,16 @@ import { computed } from 'vue'
 
 import ControlFeedback from '@/components/ControlFeedback.vue'
 import { useControlInterface } from '@/composables/useControlInterface'
+import { useLocale } from '@/lib/locale'
 
 const { controlInputMode, controlInputModeLabel, controlTuning, resetControlTuning, setControlInputMode, setControlTuning } =
   useControlInterface()
+const { t } = useLocale()
 
-const inputModes = [
-  { id: 'keyboard', label: 'Keyboard', detail: 'Use W/S, A/D, Q/E, Shift, and Space.' },
-  { id: 'gamepad', label: 'Gamepad', detail: 'Use the browser-detected controller only.' },
-] as const
+const inputModes = computed(() => [
+  { id: 'keyboard', label: t('common.keyboard'), detail: t('controlPanel.keyboardDetail') },
+  { id: 'gamepad', label: t('common.gamepad'), detail: t('controlPanel.gamepadDetail') },
+] as const)
 
 const forwardSpeed = computed({
   get: () => controlTuning.value.forward,
@@ -37,24 +39,24 @@ const turboMultiplier = computed({
   <section class="panel control-panel">
     <div class="panel-head">
       <div>
-        <p class="eyebrow">Control</p>
-        <h2>Control Feedback</h2>
+        <p class="eyebrow">{{ t('controlPanel.eyebrow') }}</p>
+        <h2>{{ t('controlPanel.title') }}</h2>
       </div>
       <button type="button" class="reset-button" @click="resetControlTuning">
-        Reset Defaults
+        {{ t('controlPanel.resetDefaults') }}
       </button>
     </div>
 
     <section class="mode-panel">
       <div class="mode-panel-head">
         <div>
-          <p class="mode-eyebrow">Input Mode</p>
-          <p class="mode-copy">Only one local input mode can control the page at a time.</p>
+          <p class="mode-eyebrow">{{ t('controlPanel.inputModeEyebrow') }}</p>
+          <p class="mode-copy">{{ t('controlPanel.inputModeCopy') }}</p>
         </div>
         <strong class="mode-current">{{ controlInputModeLabel }}</strong>
       </div>
 
-      <div class="mode-toggle" role="radiogroup" aria-label="Control input mode">
+      <div class="mode-toggle" role="radiogroup" :aria-label="t('controlPanel.inputModeEyebrow')">
         <button
           v-for="mode in inputModes"
           :key="mode.id"
@@ -72,25 +74,25 @@ const turboMultiplier = computed({
 
     <div class="tuning-grid">
       <label class="tuning-field">
-        <span>Forward</span>
+        <span>{{ t('controlPanel.forward') }}</span>
         <input v-model.number="forwardSpeed" type="number" min="0.05" max="3" step="0.05" />
         <small>m/s</small>
       </label>
 
       <label class="tuning-field">
-        <span>Strafe</span>
+        <span>{{ t('controlPanel.strafe') }}</span>
         <input v-model.number="strafeSpeed" type="number" min="0.05" max="3" step="0.05" />
         <small>m/s</small>
       </label>
 
       <label class="tuning-field">
-        <span>Turn</span>
+        <span>{{ t('controlPanel.turn') }}</span>
         <input v-model.number="turnSpeed" type="number" min="0.05" max="3" step="0.05" />
         <small>rad/s</small>
       </label>
 
       <label class="tuning-field">
-        <span>Turbo</span>
+        <span>{{ t('controlPanel.turbo') }}</span>
         <input v-model.number="turboMultiplier" type="number" min="1" max="3" step="0.1" />
         <small>x</small>
       </label>
@@ -99,15 +101,13 @@ const turboMultiplier = computed({
     <ControlFeedback />
 
     <p class="hint">
-      Keyboard mapping: <code>W/S</code> forward-back, <code>A/D</code> strafe, <code>Q/E</code> turn,
-      <code>Shift</code> turbo, <code>Space</code> stop.
+      {{ t('controlPanel.keyboardHint') }}
     </p>
     <p class="hint subtle">
-      Speed tuning is shared by both local input modes and is saved in this browser.
+      {{ t('controlPanel.tuningHint') }}
     </p>
     <p class="hint subtle">
-      Browser gamepad mode uses the left stick to drive, the right stick to turn,
-      <code>RB</code> to boost, and <code>A</code> to send stop.
+      {{ t('controlPanel.gamepadHint') }}
     </p>
   </section>
 </template>
diff --git a/frontend/src/components/GpsMapPanel.vue b/frontend/src/components/GpsMapPanel.vue
index d8d1300..76252e1 100644
--- a/frontend/src/components/GpsMapPanel.vue
+++ b/frontend/src/components/GpsMapPanel.vue
@@ -1,6 +1,7 @@
 <script setup lang="ts">
 import { computed, onMounted, ref, watch } from 'vue'
 
+import { formatDateTime, useLocale, type MessageKey } from '@/lib/locale'
 import type { GpsTelemetry } from '@/types'
 
 declare global {
@@ -16,12 +17,19 @@ const props = defineProps<{
   gps: GpsTelemetry | null
 }>()
 
+const { locale, t } = useLocale()
+
 const STORAGE_KEY = 'robot_command_center_amap'
 
+type StatusState = {
+  key: MessageKey
+  params?: Record<string, string | number | null | undefined>
+}
+
 const keyInput = ref('')
 const securityCodeInput = ref('')
-const statusText = ref('等待加载高德地图。')
-const amapCoordinateText = ref('暂无')
+const statusState = ref<StatusState>({ key: 'gpsMap.status.waitingInit' })
+const amapCoordinateRaw = ref('')
 const mapElement = ref<HTMLDivElement | null>(null)
 const mapRunning = ref(false)
 
@@ -30,6 +38,12 @@ let mapInstance: any = null
 let marker: any = null
 let infoWindow: any = null
 
+function setStatus(key: MessageKey, params?: Record<string, string | number | null | undefined>) {
+  statusState.value = { key, params }
+}
+
+const statusText = computed(() => t(statusState.value.key, statusState.value.params))
+
 function readSavedCredentials() {
   try {
     const raw = localStorage.getItem(STORAGE_KEY)
@@ -54,7 +68,7 @@ function formatNumber(value: number) {
 }
 
 function formatHexText(value: string | null | undefined) {
-  return value || '暂无'
+  return value || t('gpsMap.noValue')
 }
 
 async function loadAmapScript(key: string, securityJsCode: string) {
@@ -73,7 +87,7 @@ async function loadAmapScript(key: string, securityJsCode: string) {
     script.src = `https://webapi.amap.com/maps?v=2.0&key=${encodeURIComponent(key)}`
     script.async = true
     script.onload = () => resolve(window.AMap)
-    script.onerror = () => reject(new Error('高德地图脚本加载失败，请检查 Key / jscode 和网络。'))
+    script.onerror = () => reject(new Error(t('gpsMap.status.loadFailed')))
     document.head.appendChild(script)
   })
 
@@ -94,7 +108,7 @@ function ensureMap() {
 
   marker = new window.AMap.Marker({
     anchor: 'bottom-center',
-    title: 'Robot GPS',
+    title: t('gpsMap.infoTitle'),
   })
 
   infoWindow = new window.AMap.InfoWindow({
@@ -104,7 +118,7 @@ function ensureMap() {
 
 function stopMap() {
   mapRunning.value = false
-  amapCoordinateText.value = '已停止'
+  amapCoordinateRaw.value = ''
 
   if (infoWindow) {
     infoWindow.close()
@@ -128,7 +142,23 @@ function stopMap() {
     mapElement.value.innerHTML = ''
   }
 
-  statusText.value = '已停止高德地图加载与坐标转换。需要时再点击“加载地图”即可。'
+  setStatus('gpsMap.status.stopped')
+}
+
+function buildInfoWindowContent(gps: GpsTelemetry, lat: number, lng: number) {
+  const altitudeText = gps.altitude_m == null ? t('common.unknown') : `${gps.altitude_m} m`
+  return [
+    '<div style="min-width: 240px; padding: 6px 2px; line-height: 1.75; font-size: 13px; color: #152033;">',
+    `<div style="margin-bottom: 8px; font-size: 14px; font-weight: 700; color: #0f172a;">${t('gpsMap.infoTitle')}</div>`,
+    `<div><span style="color: #667085;">${t('gpsMap.wgs84')}:</span> <strong style="color: #0f172a;">${formatNumber(gps.latitude!)}, ${formatNumber(gps.longitude!)}</strong></div>`,
+    `<div><span style="color: #667085;">${t('gpsMap.gcj02')}:</span> <strong style="color: #0f172a;">${formatNumber(lat)}, ${formatNumber(lng)}</strong></div>`,
+    `<div><span style="color: #667085;">${t('gpsMap.rawLatHex')}:</span> <strong style="color: #0f172a;">${formatHexText(gps.raw_latitude_hex)}</strong></div>`,
+    `<div><span style="color: #667085;">${t('gpsMap.rawLonHex')}:</span> <strong style="color: #0f172a;">${formatHexText(gps.raw_longitude_hex)}</strong></div>`,
+    `<div><span style="color: #667085;">${t('gpsMap.utcTime')}:</span> <strong style="color: #0f172a;">${gps.utc_time || '--:--:--'}</strong></div>`,
+    `<div><span style="color: #667085;">${t('gpsMap.infoSatellites')}:</span> <strong style="color: #0f172a;">${gps.satellites ?? t('common.unknown')}</strong></div>`,
+    `<div><span style="color: #667085;">${t('gpsMap.infoAltitude')}:</span> <strong style="color: #0f172a;">${altitudeText}</strong></div>`,
+    '</div>',
+  ].join('')
 }
 
 function updateMap(gps: GpsTelemetry | null) {
@@ -137,10 +167,10 @@ function updateMap(gps: GpsTelemetry | null) {
   }
 
   if (!gps?.has_fix || gps.latitude == null || gps.longitude == null) {
-    amapCoordinateText.value = '暂无'
+    amapCoordinateRaw.value = ''
     marker?.setMap(null)
     infoWindow?.close()
-    statusText.value = gps ? 'GPS 在线，但当前还没有有效定位。' : '等待 GPS 数据。'
+    setStatus(gps ? 'gpsMap.status.noFix' : 'gpsMap.status.waitingGps')
     return
   }
 
@@ -149,7 +179,7 @@ function updateMap(gps: GpsTelemetry | null) {
 
   window.AMap.convertFrom([rawLongitude, rawLatitude], 'gps', (status: string, result: any) => {
     if (status !== 'complete' || !result?.locations?.length) {
-      statusText.value = 'GPS 坐标转换失败。'
+      setStatus('gpsMap.status.convertFailed')
       return
     }
 
@@ -157,27 +187,14 @@ function updateMap(gps: GpsTelemetry | null) {
     const lng = typeof point.getLng === 'function' ? point.getLng() : point.lng
     const lat = typeof point.getLat === 'function' ? point.getLat() : point.lat
 
-    amapCoordinateText.value = `${formatNumber(lat)}, ${formatNumber(lng)}`
+    amapCoordinateRaw.value = `${formatNumber(lat)}, ${formatNumber(lng)}`
     marker.setPosition([lng, lat])
     marker.setMap(mapInstance)
 
-    infoWindow.setContent(
-      [
-        '<div style="min-width: 240px; padding: 6px 2px; line-height: 1.75; font-size: 13px; color: #152033;">',
-        '<div style="margin-bottom: 8px; font-size: 14px; font-weight: 700; color: #0f172a;">Robot GPS 定位</div>',
-        `<div><span style="color: #667085;">WGS84:</span> <strong style="color: #0f172a;">${formatNumber(rawLatitude)}, ${formatNumber(rawLongitude)}</strong></div>`,
-        `<div><span style="color: #667085;">高德 GCJ-02:</span> <strong style="color: #0f172a;">${formatNumber(lat)}, ${formatNumber(lng)}</strong></div>`,
-        `<div><span style="color: #667085;">纬度原始 8B:</span> <strong style="color: #0f172a;">${formatHexText(gps.raw_latitude_hex)}</strong></div>`,
-        `<div><span style="color: #667085;">经度原始 8B:</span> <strong style="color: #0f172a;">${formatHexText(gps.raw_longitude_hex)}</strong></div>`,
-        `<div><span style="color: #667085;">UTC 时间:</span> <strong style="color: #0f172a;">${gps.utc_time || '--:--:--'}</strong></div>`,
-        `<div><span style="color: #667085;">卫星数:</span> <strong style="color: #0f172a;">${gps.satellites ?? '未知'}</strong></div>`,
-        `<div><span style="color: #667085;">海拔:</span> <strong style="color: #0f172a;">${gps.altitude_m ?? '未知'} m</strong></div>`,
-        '</div>',
-      ].join(''),
-    )
+    infoWindow.setContent(buildInfoWindowContent(gps, lat, lng))
     infoWindow.open(mapInstance, [lng, lat])
     mapInstance.setZoomAndCenter(17, [lng, lat])
-    statusText.value = `地图已刷新，数据源：${gps.source_mode}`
+    setStatus('gpsMap.status.refreshedSource', { source: gps.source_mode })
   })
 }
 
@@ -186,58 +203,55 @@ async function startMap() {
   const securityJsCode = securityCodeInput.value.trim()
 
   if (!key || !securityJsCode) {
-    statusText.value = '请先填写高德 Key 和安全密钥 jscode。'
+    setStatus('gpsMap.status.fillCredentials')
     return
   }
 
-  statusText.value = '正在加载高德地图...'
+  setStatus('gpsMap.status.loading')
 
   try {
     await loadAmapScript(key, securityJsCode)
     ensureMap()
     saveCredentials()
     mapRunning.value = true
-    statusText.value = '地图已加载。'
+    setStatus('gpsMap.status.loaded')
     updateMap(props.gps)
   } catch (error) {
-    statusText.value = error instanceof Error ? error.message : '地图加载失败。'
+    setStatus('gpsMap.status.loadFailed')
+    if (error instanceof Error && error.message) {
+      statusState.value = { key: 'gpsMap.status.loadFailed', params: { message: error.message } }
+    }
   }
 }
 
 const rawCoordinateText = computed(() => {
   if (!props.gps?.has_fix || props.gps.latitude == null || props.gps.longitude == null) {
-    return '暂无有效定位'
+    return t('gpsMap.noValidFix')
   }
-
   return `${formatNumber(props.gps.latitude)}, ${formatNumber(props.gps.longitude)}`
 })
 
+const amapCoordinateText = computed(() => amapCoordinateRaw.value || t('gpsMap.noValue'))
 const rawLatitudeHexText = computed(() => formatHexText(props.gps?.raw_latitude_hex))
-
 const rawLongitudeHexText = computed(() => formatHexText(props.gps?.raw_longitude_hex))
 
 const coordinateMetaText = computed(() => {
   if (!props.gps) {
-    return '暂无'
+    return t('gpsMap.noValue')
   }
   return `${props.gps.coordinate_system} / ${props.gps.raw_coordinate_format}`
 })
 
 const metaText = computed(() => {
   if (!props.gps) {
-    return '暂无'
+    return t('gpsMap.noValue')
   }
-  const satellites = props.gps.satellites ?? '未知'
-  const altitude = props.gps.altitude_m == null ? '未知' : `${props.gps.altitude_m} m`
-  return `${satellites} 颗 / ${altitude}`
+  const satellites = props.gps.satellites ?? t('common.unknown')
+  const altitude = props.gps.altitude_m == null ? t('common.unknown') : `${props.gps.altitude_m} m`
+  return `${satellites} / ${altitude}`
 })
 
-const updatedAtText = computed(() => {
-  if (!props.gps?.updated_at) {
-    return '暂无'
-  }
-  return new Date(props.gps.updated_at).toLocaleString('zh-CN', { hour12: false })
-})
+const updatedAtText = computed(() => formatDateTime(props.gps?.updated_at))
 
 onMounted(() => {
   const saved = readSavedCredentials()
@@ -245,7 +259,7 @@ onMounted(() => {
     keyInput.value = saved.key ?? ''
     securityCodeInput.value = saved.securityJsCode ?? ''
     if (keyInput.value && securityCodeInput.value) {
-      statusText.value = '已恢复高德配置。高德地图不会自动加载，请按需点击“加载地图”。'
+      setStatus('gpsMap.status.restoredConfig')
     }
   }
 })
@@ -257,70 +271,76 @@ watch(
   },
   { deep: true },
 )
+
+watch(
+  () => locale.value,
+  () => {
+    if (mapRunning.value) {
+      updateMap(props.gps)
+    }
+  },
+)
 </script>
 
 <template>
   <section class="panel map-panel">
     <div class="panel-head">
       <div>
-        <p class="eyebrow">GPS</p>
-        <h2>地图定位</h2>
+        <p class="eyebrow">{{ t('gpsMap.eyebrow') }}</p>
+        <h2>{{ t('gpsMap.title') }}</h2>
       </div>
-      <span class="badge">{{ gps?.source_mode ?? 'loading' }}</span>
+      <span class="badge">{{ gps?.source_mode ?? t('common.loading') }}</span>
     </div>
 
-    <p class="intro">
-      这里复用了你原来 `GeoStream/gps_map.html` 的高德地图思路。后端优先读取
-      `GeoStream/gps_latest.json`，所以你运行 `parse_gps.c` 生成数据后，这里会直接接上。
-    </p>
+    <p class="intro">{{ t('gpsMap.intro') }}</p>
 
     <div class="credentials">
-      <input v-model="keyInput" type="text" placeholder="高德 Web 端 Key" />
-      <input v-model="securityCodeInput" type="text" placeholder="安全密钥 jscode" />
-      <button type="button" @click="startMap">加载地图</button>
-      <button type="button" class="secondary" @click="stopMap">停止加载</button>
+      <input v-model="keyInput" type="text" :placeholder="t('gpsMap.keyPlaceholder')" />
+      <input v-model="securityCodeInput" type="text" :placeholder="t('gpsMap.jscodePlaceholder')" />
+      <button type="button" @click="startMap">{{ t('gpsMap.loadMap') }}</button>
+      <button type="button" class="secondary" @click="stopMap">{{ t('gpsMap.stopMap') }}</button>
     </div>
 
     <div class="status">{{ statusText }}</div>
 
     <div class="details">
       <div class="detail-card">
-        <span>WGS84 坐标</span>
+        <span>{{ t('gpsMap.wgs84') }}</span>
         <strong>{{ rawCoordinateText }}</strong>
       </div>
       <div class="detail-card">
-        <span>高德 GCJ-02</span>
+        <span>{{ t('gpsMap.gcj02') }}</span>
         <strong>{{ amapCoordinateText }}</strong>
       </div>
       <div class="detail-card">
-        <span>纬度原始 8 字节</span>
+        <span>{{ t('gpsMap.rawLatHex') }}</span>
         <strong class="mono">{{ rawLatitudeHexText }}</strong>
       </div>
       <div class="detail-card">
-        <span>经度原始 8 字节</span>
+        <span>{{ t('gpsMap.rawLonHex') }}</span>
         <strong class="mono">{{ rawLongitudeHexText }}</strong>
       </div>
       <div class="detail-card">
-        <span>UTC 时间</span>
+        <span>{{ t('gpsMap.utcTime') }}</span>
         <strong>{{ gps?.utc_time ?? '--:--:--' }}</strong>
       </div>
       <div class="detail-card">
-        <span>卫星 / 海拔</span>
+        <span>{{ t('gpsMap.satAltitude') }}</span>
         <strong>{{ metaText }}</strong>
       </div>
       <div class="detail-card">
-        <span>坐标系 / 格式</span>
+        <span>{{ t('gpsMap.coordMeta') }}</span>
         <strong>{{ coordinateMetaText }}</strong>
       </div>
       <div class="detail-card">
-        <span>最近刷新</span>
+        <span>{{ t('gpsMap.lastUpdated') }}</span>
         <strong>{{ updatedAtText }}</strong>
       </div>
     </div>
 
     <div ref="mapElement" class="map-canvas" :class="{ stopped: !mapRunning }">
       <div v-if="!mapRunning" class="map-placeholder">
-        高德地图当前未加载。点击上方“加载地图”后才会开始请求地图与坐标转换服务。
+        {{ t('gpsMap.mapPlaceholder') }}
       </div>
     </div>
   </section>
@@ -423,7 +443,7 @@ h2 {
 }
 
 .detail-card strong.mono {
-  font-family: "JetBrains Mono", "SFMono-Regular", monospace;
+  font-family: 'JetBrains Mono', 'SFMono-Regular', monospace;
   font-size: 14px;
 }
 
diff --git a/frontend/src/components/NetworkPanel.vue b/frontend/src/components/NetworkPanel.vue
index 60d0ef1..3d83a09 100644
--- a/frontend/src/components/NetworkPanel.vue
+++ b/frontend/src/components/NetworkPanel.vue
@@ -1,6 +1,7 @@
 <script setup lang="ts">
 import { computed } from 'vue'
 
+import { formatDateTime, t } from '@/lib/locale'
 import type { LinkSessionTelemetry, LinkTelemetry, NetworkTelemetry } from '@/types'
 
 const props = defineProps<{
@@ -20,13 +21,10 @@ const legCards = computed(() => [
   },
 ])
 
-const activeSource = computed(() => props.network?.active_control_source ?? 'none')
+const activeSource = computed(() => formatControlSource(props.network?.active_control_source))
 
 function formatTime(value?: string | null) {
-  if (!value) {
-    return 'unavailable'
-  }
-  return new Date(value).toLocaleString('zh-CN', { hour12: false })
+  return formatDateTime(value)
 }
 
 function formatScalar(value?: number | string | null, suffix = '') {
@@ -45,64 +43,105 @@ function legSessions(link: LinkTelemetry | null): Array<{ name: string; data: Li
     { name: 'video', data: link?.sessions?.video ?? null },
   ]
 }
+
+function formatControlSource(source?: string | null) {
+  if (source === 'keyboard') return t('common.keyboard')
+  if (source === 'gamepad') return t('common.gamepad')
+  return t('common.none')
+}
+
+function formatBoolean(value?: boolean | number | null) {
+  if (value === null || value === undefined) {
+    return t('common.na')
+  }
+  return value ? t('common.yes') : t('common.no')
+}
+
+function formatAckMode(ackAvailable?: boolean) {
+  return ackAvailable ? t('common.ackLoop') : t('common.srttFallback')
+}
+
+function formatStale(stale?: boolean | null) {
+  if (stale == null) {
+    return t('common.na')
+  }
+  return stale ? t('common.stale') : t('common.fresh')
+}
+
+function formatOnline(online?: boolean | null) {
+  if (online == null) {
+    return t('common.na')
+  }
+  return online ? t('common.online') : t('common.idle')
+}
+
+function formatSessionName(name: string) {
+  return name === 'control' ? t('common.control') : t('common.video')
+}
+
+function formatTrend(value?: string | null) {
+  if (value === 'rising') return t('common.rising')
+  if (value === 'falling') return t('common.falling')
+  return t('common.stable')
+}
 </script>
 
 <template>
   <section class="panel network-panel">
     <div class="panel-head">
       <div>
-        <p class="eyebrow">Network</p>
-        <h2>Dual-Leg Telemetry</h2>
+        <p class="eyebrow">{{ t('networkPanel.eyebrow') }}</p>
+        <h2>{{ t('networkPanel.title') }}</h2>
       </div>
       <span class="badge" :class="{ stale: network?.telemetry_receiver?.hub_stale }">
-        {{ network?.peer_status ?? 'loading' }}
+        {{ network?.peer_status ?? t('networkPanel.loadingPeer') }}
       </span>
     </div>
 
     <div class="stats">
       <div class="stat-card">
-        <span>Control Loop RTT</span>
+        <span>{{ t('networkPanel.controlLoopRtt') }}</span>
         <strong>{{ formatScalar(network?.latency_estimate?.control_loop_rtt_ms, ' ms') }}</strong>
       </div>
       <div class="stat-card">
-        <span>Control to Persist</span>
+        <span>{{ t('networkPanel.controlToPersist') }}</span>
         <strong>{{ formatScalar(network?.latency_estimate?.control_to_persist_est_ms, ' ms') }}</strong>
       </div>
       <div class="stat-card">
-        <span>Control SRTT One-way</span>
+        <span>{{ t('networkPanel.controlSrttOneWay') }}</span>
         <strong>{{ formatScalar(network?.latency_estimate?.control_oneway_srtt_est_ms, ' ms') }}</strong>
       </div>
       <div class="stat-card">
-        <span>Video One-way Est.</span>
+        <span>{{ t('networkPanel.videoOneWayEst') }}</span>
         <strong>{{ formatScalar(network?.latency_estimate?.video_network_oneway_est_ms, ' ms') }}</strong>
       </div>
       <div class="stat-card">
-        <span>TX Rate</span>
+        <span>{{ t('networkPanel.txRate') }}</span>
         <strong>{{ formatScalar(network?.tx_kbps, ' kbps') }}</strong>
       </div>
       <div class="stat-card">
-        <span>RX Rate</span>
+        <span>{{ t('networkPanel.rxRate') }}</span>
         <strong>{{ formatScalar(network?.rx_kbps, ' kbps') }}</strong>
       </div>
     </div>
 
     <div class="summary telemetry-strip">
-      <p><strong>Robot Fault:</strong> {{ network?.robot_health?.fault_reason ?? 'n/a' }}</p>
-      <p><strong>Recovery State:</strong> {{ network?.robot_health?.recovery_state ?? 'n/a' }}</p>
-      <p><strong>Health Confidence:</strong> {{ network?.robot_health?.confidence ?? 'n/a' }}</p>
-      <p><strong>Health Updated:</strong> {{ formatTime(network?.robot_health?.updated_at) }}</p>
-      <p><strong>Transport:</strong> {{ network?.transport ?? 'n/a' }} / {{ network?.source_mode ?? 'n/a' }}</p>
-      <p><strong>Active Control:</strong> {{ activeSource }}</p>
-      <p><strong>Lease:</strong> {{ formatScalar(network?.control_lease_remaining_ms, ' ms') }}</p>
-      <p><strong>ACK Mode:</strong> {{ network?.control_ack_status?.ack_available ? 'ack-loop' : 'srtt-fallback' }}</p>
-      <p><strong>ACK Updated:</strong> {{ formatTime(network?.control_ack_status?.updated_at) }}</p>
-      <p><strong>Telemetry Peer:</strong> {{ network?.telemetry_receiver?.peer_id ?? 'n/a' }}</p>
-      <p><strong>Telemetry Registered:</strong> {{ network?.telemetry_receiver?.registered ? 'yes' : 'no' }}</p>
-      <p><strong>Hub Freshness:</strong> {{ formatTime(network?.telemetry_receiver?.hub_updated_at) }}</p>
-      <p><strong>Hub State:</strong> {{ network?.telemetry_receiver?.hub_stale ? 'stale' : 'fresh' }}</p>
-      <p><strong>Telemetry Reconnects:</strong> {{ network?.telemetry_receiver?.reconnect_count ?? 0 }}</p>
-      <p v-if="network?.telemetry_receiver?.last_error"><strong>Hub Error:</strong> {{ network?.telemetry_receiver?.last_error }}</p>
-      <p v-if="network?.telemetry_receiver?.last_server_error"><strong>Telemetry Session Error:</strong> {{ network?.telemetry_receiver?.last_server_error }}</p>
+      <p><strong>{{ t('networkPanel.robotFault') }}:</strong> {{ network?.robot_health?.fault_reason ?? t('common.na') }}</p>
+      <p><strong>{{ t('networkPanel.recoveryState') }}:</strong> {{ network?.robot_health?.recovery_state ?? t('common.na') }}</p>
+      <p><strong>{{ t('networkPanel.healthConfidence') }}:</strong> {{ network?.robot_health?.confidence ?? t('common.na') }}</p>
+      <p><strong>{{ t('networkPanel.healthUpdated') }}:</strong> {{ formatTime(network?.robot_health?.updated_at) }}</p>
+      <p><strong>{{ t('networkPanel.transport') }}:</strong> {{ network?.transport ?? t('common.na') }} / {{ network?.source_mode ?? t('common.na') }}</p>
+      <p><strong>{{ t('networkPanel.activeControl') }}:</strong> {{ activeSource }}</p>
+      <p><strong>{{ t('networkPanel.lease') }}:</strong> {{ formatScalar(network?.control_lease_remaining_ms, ' ms') }}</p>
+      <p><strong>{{ t('networkPanel.ackMode') }}:</strong> {{ formatAckMode(network?.control_ack_status?.ack_available) }}</p>
+      <p><strong>{{ t('networkPanel.ackUpdated') }}:</strong> {{ formatTime(network?.control_ack_status?.updated_at) }}</p>
+      <p><strong>{{ t('networkPanel.telemetryPeer') }}:</strong> {{ network?.telemetry_receiver?.peer_id ?? t('common.na') }}</p>
+      <p><strong>{{ t('networkPanel.telemetryRegistered') }}:</strong> {{ formatBoolean(network?.telemetry_receiver?.registered) }}</p>
+      <p><strong>{{ t('networkPanel.hubFreshness') }}:</strong> {{ formatTime(network?.telemetry_receiver?.hub_updated_at) }}</p>
+      <p><strong>{{ t('networkPanel.hubState') }}:</strong> {{ formatStale(network?.telemetry_receiver?.hub_stale) }}</p>
+      <p><strong>{{ t('networkPanel.telemetryReconnects') }}:</strong> {{ network?.telemetry_receiver?.reconnect_count ?? 0 }}</p>
+      <p v-if="network?.telemetry_receiver?.last_error"><strong>{{ t('networkPanel.hubError') }}:</strong> {{ network?.telemetry_receiver?.last_error }}</p>
+      <p v-if="network?.telemetry_receiver?.last_server_error"><strong>{{ t('networkPanel.telemetrySessionError') }}:</strong> {{ network?.telemetry_receiver?.last_server_error }}</p>
     </div>
 
     <div class="leg-grid">
@@ -110,11 +149,11 @@ function legSessions(link: LinkTelemetry | null): Array<{ name: string; data: Li
         <div class="leg-head">
           <div>
             <p class="leg-label">{{ leg.label }}</p>
-            <h3>{{ leg.data?.source ?? 'waiting' }}</h3>
+            <h3>{{ leg.data?.source ?? t('common.waiting') }}</h3>
           </div>
           <div class="leg-meta">
             <span class="mini-badge" :class="{ stale: leg.data?.stale }">
-              {{ leg.data?.stale ? 'stale' : 'fresh' }}
+              {{ formatStale(leg.data?.stale) }}
             </span>
             <span class="mini-time">{{ formatTime(leg.data?.updated_at) }}</span>
           </div>
@@ -122,27 +161,27 @@ function legSessions(link: LinkTelemetry | null): Array<{ name: string; data: Li
 
         <div class="aggregate-grid">
           <div>
-            <span>Online</span>
+            <span>{{ t('networkPanel.online') }}</span>
             <strong>{{ leg.data?.aggregate?.online_sessions ?? 0 }}</strong>
           </div>
           <div>
-            <span>Max Pressure</span>
+            <span>{{ t('networkPanel.maxPressure') }}</span>
             <strong>{{ formatScalar(leg.data?.aggregate?.max_window_pressure_pct, '%') }}</strong>
           </div>
           <div>
-            <span>Queued</span>
+            <span>{{ t('networkPanel.queued') }}</span>
             <strong>{{ leg.data?.aggregate?.sum_snd_queue ?? 0 }}</strong>
           </div>
           <div>
-            <span>In Flight Buffer</span>
+            <span>{{ t('networkPanel.inFlightBuffer') }}</span>
             <strong>{{ leg.data?.aggregate?.sum_snd_buffer ?? 0 }}</strong>
           </div>
           <div>
-            <span>Retrans Delta</span>
+            <span>{{ t('networkPanel.retransDelta') }}</span>
             <strong>{{ leg.data?.aggregate?.sum_retrans_delta ?? 0 }}</strong>
           </div>
           <div>
-            <span>Repair Rate</span>
+            <span>{{ t('networkPanel.repairRate') }}</span>
             <strong>{{ formatScalar(leg.data?.aggregate?.repair_rate_pct, '%') }}</strong>
           </div>
         </div>
@@ -151,36 +190,36 @@ function legSessions(link: LinkTelemetry | null): Array<{ name: string; data: Li
           <section v-for="session in legSessions(leg.data)" :key="session.name" class="session-card">
             <div class="session-head">
               <div>
-                <p class="session-label">{{ session.name }}</p>
-                <h4>{{ session.data?.peer_id ?? 'unassigned' }}</h4>
+                <p class="session-label">{{ formatSessionName(session.name) }}</p>
+                <h4>{{ session.data?.peer_id ?? t('networkPanel.unassigned') }}</h4>
               </div>
               <span class="mini-badge" :class="{ stale: session.data?.stale, active: session.data?.connected }">
-                {{ session.data?.connected ? 'online' : 'idle' }}
+                {{ formatOnline(session.data?.connected) }}
               </span>
             </div>
 
             <div class="kv-grid">
-              <p><strong>Updated:</strong> {{ formatTime(session.data?.updated_at) }}</p>
-              <p><strong>SRTT:</strong> {{ formatScalar(session.data?.kcp?.srtt_ms, ' ms') }}</p>
-              <p><strong>RTTVAR:</strong> {{ formatScalar(session.data?.kcp?.srttvar_ms, ' ms') }}</p>
-              <p><strong>RTO:</strong> {{ formatScalar(session.data?.kcp?.rto_ms, ' ms') }}</p>
-              <p><strong>SND WND:</strong> {{ formatScalar(session.data?.kcp?.snd_wnd) }}</p>
-              <p><strong>RMT WND:</strong> {{ formatScalar(session.data?.kcp?.rmt_wnd) }}</p>
-              <p><strong>Inflight:</strong> {{ formatScalar(session.data?.kcp?.inflight) }}</p>
-              <p><strong>Window Limit:</strong> {{ formatScalar(session.data?.kcp?.window_limit) }}</p>
-              <p><strong>Pressure:</strong> {{ formatScalar(session.data?.kcp?.window_pressure_pct, '%') }}</p>
-              <p><strong>SND Queue:</strong> {{ formatScalar(session.data?.kcp?.snd_queue) }} / {{ session.data?.trend?.snd_queue_trend ?? 'stable' }}</p>
-              <p><strong>SND Buffer:</strong> {{ formatScalar(session.data?.kcp?.snd_buffer) }} / {{ session.data?.trend?.snd_buffer_trend ?? 'stable' }}</p>
-              <p><strong>Queue Delta:</strong> {{ formatScalar(session.data?.trend?.snd_queue_delta) }}</p>
-              <p><strong>Buffer Delta:</strong> {{ formatScalar(session.data?.trend?.snd_buffer_delta) }}</p>
-              <p><strong>Retrans:</strong> {{ formatScalar(session.data?.trend?.retrans_delta) }}</p>
-              <p><strong>Fast Retrans:</strong> {{ formatScalar(session.data?.trend?.fast_retrans_delta) }}</p>
-              <p><strong>Lost:</strong> {{ formatScalar(session.data?.trend?.lost_delta) }}</p>
-              <p><strong>Repeat:</strong> {{ formatScalar(session.data?.trend?.repeat_delta) }}</p>
-              <p><strong>Repair Rate:</strong> {{ formatScalar(session.data?.trend?.repair_rate_pct, '%') }}</p>
-              <p v-if="session.data?.app"><strong>App Bytes:</strong> tx={{ session.data.app.send_bytes ?? 0 }} / rx={{ session.data.app.recv_bytes ?? 0 }}</p>
-              <p v-if="session.data?.app"><strong>Registered:</strong> {{ session.data.app.registered ? 'yes' : 'no' }}</p>
-              <p v-if="session.data?.app?.last_server_error"><strong>Server Error:</strong> {{ session.data.app.last_server_error }}</p>
+              <p><strong>{{ t('networkPanel.updated') }}:</strong> {{ formatTime(session.data?.updated_at) }}</p>
+              <p><strong>{{ t('networkPanel.srtt') }}:</strong> {{ formatScalar(session.data?.kcp?.srtt_ms, ' ms') }}</p>
+              <p><strong>{{ t('networkPanel.rttvar') }}:</strong> {{ formatScalar(session.data?.kcp?.srttvar_ms, ' ms') }}</p>
+              <p><strong>{{ t('networkPanel.rto') }}:</strong> {{ formatScalar(session.data?.kcp?.rto_ms, ' ms') }}</p>
+              <p><strong>{{ t('networkPanel.sndWnd') }}:</strong> {{ formatScalar(session.data?.kcp?.snd_wnd) }}</p>
+              <p><strong>{{ t('networkPanel.rmtWnd') }}:</strong> {{ formatScalar(session.data?.kcp?.rmt_wnd) }}</p>
+              <p><strong>{{ t('networkPanel.inflight') }}:</strong> {{ formatScalar(session.data?.kcp?.inflight) }}</p>
+              <p><strong>{{ t('networkPanel.windowLimit') }}:</strong> {{ formatScalar(session.data?.kcp?.window_limit) }}</p>
+              <p><strong>{{ t('networkPanel.pressure') }}:</strong> {{ formatScalar(session.data?.kcp?.window_pressure_pct, '%') }}</p>
+              <p><strong>{{ t('networkPanel.sndQueue') }}:</strong> {{ formatScalar(session.data?.kcp?.snd_queue) }} / {{ formatTrend(session.data?.trend?.snd_queue_trend) }}</p>
+              <p><strong>{{ t('networkPanel.sndBuffer') }}:</strong> {{ formatScalar(session.data?.kcp?.snd_buffer) }} / {{ formatTrend(session.data?.trend?.snd_buffer_trend) }}</p>
+              <p><strong>{{ t('networkPanel.queueDelta') }}:</strong> {{ formatScalar(session.data?.trend?.snd_queue_delta) }}</p>
+              <p><strong>{{ t('networkPanel.bufferDelta') }}:</strong> {{ formatScalar(session.data?.trend?.snd_buffer_delta) }}</p>
+              <p><strong>{{ t('networkPanel.retrans') }}:</strong> {{ formatScalar(session.data?.trend?.retrans_delta) }}</p>
+              <p><strong>{{ t('networkPanel.fastRetrans') }}:</strong> {{ formatScalar(session.data?.trend?.fast_retrans_delta) }}</p>
+              <p><strong>{{ t('networkPanel.lost') }}:</strong> {{ formatScalar(session.data?.trend?.lost_delta) }}</p>
+              <p><strong>{{ t('networkPanel.repeat') }}:</strong> {{ formatScalar(session.data?.trend?.repeat_delta) }}</p>
+              <p><strong>{{ t('networkPanel.repairRate') }}:</strong> {{ formatScalar(session.data?.trend?.repair_rate_pct, '%') }}</p>
+              <p v-if="session.data?.app"><strong>{{ t('networkPanel.appBytes') }}:</strong> tx={{ session.data.app.send_bytes ?? 0 }} / rx={{ session.data.app.recv_bytes ?? 0 }}</p>
+              <p v-if="session.data?.app"><strong>{{ t('networkPanel.registered') }}:</strong> {{ formatBoolean(session.data.app.registered) }}</p>
+              <p v-if="session.data?.app?.last_server_error"><strong>{{ t('networkPanel.serverError') }}:</strong> {{ session.data.app.last_server_error }}</p>
             </div>
           </section>
         </div>
@@ -188,15 +227,15 @@ function legSessions(link: LinkTelemetry | null): Array<{ name: string; data: Li
     </div>
 
     <div class="summary">
-      <p><strong>Combined:</strong> sessions={{ network?.combined?.connected_sessions ?? 0 }} send={{ network?.combined?.send_bytes ?? 0 }}B recv={{ network?.combined?.recv_bytes ?? 0 }}B</p>
-      <p><strong>Video E2E Est.:</strong> {{ formatScalar(network?.latency_estimate?.video_e2e_est_ms, ' ms') }} / confidence={{ network?.latency_estimate?.confidence?.video ?? 'n/a' }}</p>
-      <p><strong>Control Estimate Confidence:</strong> {{ network?.latency_estimate?.confidence?.control ?? 'n/a' }}</p>
-      <p><strong>Video Freshness:</strong> repeat={{ formatScalar((network?.video_freshness?.repeated_frame_ratio ?? 0) * 100, '%') }} skip={{ formatScalar((network?.video_freshness?.skip_ratio ?? 0) * 100, '%') }} freeze={{ formatScalar(network?.video_freshness?.longest_freeze_ms, ' ms') }}</p>
-      <p><strong>Native UDP:</strong> {{ network?.ingress?.native_udp?.bind_addr ?? 'n/a' }} packets={{ network?.ingress?.native_udp?.packets_received ?? 0 }} invalid={{ network?.ingress?.native_udp?.invalid_packets ?? 0 }}</p>
-      <p><strong>Control Sender:</strong> {{ network?.control?.sender?.peer_id ?? 'n/a' }} -> {{ network?.control?.sender?.target_peer ?? 'n/a' }} sends={{ network?.control?.sender?.send_count ?? 0 }} registered={{ network?.control?.sender?.registered ? 'yes' : 'no' }}</p>
-      <p><strong>ACK Receiver:</strong> {{ network?.control?.ack_receiver?.peer_id ?? 'n/a' }} reconnects={{ network?.control?.ack_receiver?.reconnect_count ?? 0 }}</p>
-      <p><strong>Control Reconnects:</strong> {{ network?.control?.sender?.reconnect_count ?? 0 }}</p>
-      <p v-if="network?.control?.sender?.last_server_error"><strong>Control Session Error:</strong> {{ network?.control?.sender?.last_server_error }}</p>
+      <p><strong>{{ t('networkPanel.combined') }}:</strong> sessions={{ network?.combined?.connected_sessions ?? 0 }} send={{ network?.combined?.send_bytes ?? 0 }}B recv={{ network?.combined?.recv_bytes ?? 0 }}B</p>
+      <p><strong>{{ t('networkPanel.videoE2E') }}:</strong> {{ formatScalar(network?.latency_estimate?.video_e2e_est_ms, ' ms') }} / confidence={{ network?.latency_estimate?.confidence?.video ?? t('common.na') }}</p>
+      <p><strong>{{ t('networkPanel.controlEstimateConfidence') }}:</strong> {{ network?.latency_estimate?.confidence?.control ?? t('common.na') }}</p>
+      <p><strong>{{ t('networkPanel.videoFreshness') }}:</strong> {{ t('networkPanel.videoFreshnessRepeat') }}={{ formatScalar((network?.video_freshness?.repeated_frame_ratio ?? 0) * 100, '%') }} {{ t('networkPanel.videoFreshnessSkip') }}={{ formatScalar((network?.video_freshness?.skip_ratio ?? 0) * 100, '%') }} {{ t('networkPanel.videoFreshnessFreeze') }}={{ formatScalar(network?.video_freshness?.longest_freeze_ms, ' ms') }}</p>
+      <p><strong>{{ t('networkPanel.nativeUdp') }}:</strong> {{ network?.ingress?.native_udp?.bind_addr ?? t('common.na') }} packets={{ network?.ingress?.native_udp?.packets_received ?? 0 }} invalid={{ network?.ingress?.native_udp?.invalid_packets ?? 0 }}</p>
+      <p><strong>{{ t('networkPanel.controlSender') }}:</strong> {{ network?.control?.sender?.peer_id ?? t('common.na') }} -> {{ network?.control?.sender?.target_peer ?? t('common.na') }} sends={{ network?.control?.sender?.send_count ?? 0 }} registered={{ formatBoolean(network?.control?.sender?.registered) }}</p>
+      <p><strong>{{ t('networkPanel.ackReceiver') }}:</strong> {{ network?.control?.ack_receiver?.peer_id ?? t('common.na') }} reconnects={{ network?.control?.ack_receiver?.reconnect_count ?? 0 }}</p>
+      <p><strong>{{ t('networkPanel.controlReconnects') }}:</strong> {{ network?.control?.sender?.reconnect_count ?? 0 }}</p>
+      <p v-if="network?.control?.sender?.last_server_error"><strong>{{ t('networkPanel.controlSessionError') }}:</strong> {{ network?.control?.sender?.last_server_error }}</p>
     </div>
   </section>
 </template>
diff --git a/frontend/src/components/VideoPanel.vue b/frontend/src/components/VideoPanel.vue
index 3e06a1c..508cc21 100644
--- a/frontend/src/components/VideoPanel.vue
+++ b/frontend/src/components/VideoPanel.vue
@@ -2,6 +2,7 @@
 import { computed, onMounted, onUnmounted, ref, watch } from 'vue'
 
 import { buildVideoFrameUrl, fetchClockCalibrationSample, fetchVideoStatus, postVideoDisplayProbe } from '@/lib/api'
+import { t } from '@/lib/locale'
 import { useOperatorInputTelemetry } from '@/composables/useControlInterface'
 import type { NetworkTelemetry, VideoStatus } from '@/types'
 
@@ -62,10 +63,10 @@ const clockCalibration = ref<ClockCalibrationSnapshot>({ ...EMPTY_CLOCK_CALIBRAT
 
 const modeLabel = computed(() => {
   if (!displayVideo.value) {
-    return 'loading'
+    return t('videoPanel.mode.loading')
   }
   if (displayVideo.value.source_mode === 'omnisocket-jpeg-live') {
-    return `${displayVideo.value.fps} FPS live`
+    return t('videoPanel.mode.live', { fps: displayVideo.value.fps })
   }
   return displayVideo.value.source_mode
 })
@@ -73,7 +74,7 @@ const modeLabel = computed(() => {
 const timingHeadline = computed(() => {
   const latest = senderClockDebug.value?.sender_clock_delta_ms_raw
   if (latest == null) {
-    return 'waiting'
+    return t('videoPanel.timing.waiting')
   }
   return `${latest.toFixed(1)} ms`
 })
@@ -81,9 +82,9 @@ const timingHeadline = computed(() => {
 const timingHint = computed(() => {
   const timing = senderClockDebug.value
   if (!timing?.available) {
-    return 'raw sender clock delta is waiting for the first valid video trailer'
+    return t('videoPanel.timing.noTrailer')
   }
-  return 'raw sender clock delta only, unsynced clocks'
+  return t('videoPanel.timing.rawHint')
 })
 
 function formatNumber(value: number | null | undefined, suffix = '') {
@@ -437,8 +438,8 @@ watch(
   <section class="panel video-panel">
     <div class="panel-head">
       <div>
-        <p class="eyebrow">Video</p>
-        <h2>Live Video</h2>
+        <p class="eyebrow">{{ t('videoPanel.eyebrow') }}</p>
+        <h2>{{ t('videoPanel.title') }}</h2>
       </div>
       <span class="badge" :class="{ bad: !displayVideo?.available }">
         {{ modeLabel }}
@@ -450,63 +451,63 @@ watch(
         v-if="canRequestFrames"
         class="video-frame"
         :src="frameUrl"
-        alt="Robot live frame"
+        :alt="t('videoPanel.frameAlt')"
       />
       <div v-else class="video-placeholder">
-        waiting for live video frames
+        {{ t('videoPanel.waitingFrames') }}
       </div>
     </div>
 
     <div class="stats">
       <div class="stat-card">
-        <span>Frames</span>
+        <span>{{ t('videoPanel.stats.frames') }}</span>
         <strong>{{ displayVideo?.frame_count ?? 0 }}</strong>
       </div>
       <div class="stat-card">
-        <span>Latest Seq</span>
+        <span>{{ t('videoPanel.stats.latestSeq') }}</span>
         <strong>{{ displayVideo?.receiver?.latest_sequence ?? '--' }}</strong>
       </div>
       <div class="stat-card">
-        <span>Video E2E Est.</span>
+        <span>{{ t('videoPanel.stats.videoE2E') }}</span>
         <strong>{{ formatNumber(networkEstimate?.video_e2e_est_ms, ' ms') }}</strong>
       </div>
       <div class="stat-card">
-        <span>Paint Delay</span>
+        <span>{{ t('videoPanel.stats.paintDelay') }}</span>
         <strong>{{ formatNumber(displayVideo?.display_probe?.request_to_paint_ms, ' ms') }}</strong>
       </div>
     </div>
 
     <div class="metric-grid">
       <div class="metric-group">
-        <h3>Pipeline Estimate</h3>
-        <p><strong>Capture to send:</strong> {{ formatNumber(displayVideo?.receiver?.latest_capture_to_send_ms, ' ms') }}</p>
-        <p><strong>Network one-way:</strong> {{ formatNumber(networkEstimate?.video_network_oneway_est_ms, ' ms') }}</p>
-        <p><strong>Partial estimate:</strong> {{ formatNumber(networkEstimate?.video_partial_est_ms, ' ms') }}</p>
-        <p><strong>End-to-end estimate:</strong> {{ formatNumber(networkEstimate?.video_e2e_est_ms, ' ms') }}</p>
+        <h3>{{ t('videoPanel.section.pipeline') }}</h3>
+        <p><strong>{{ t('videoPanel.captureToSend') }}:</strong> {{ formatNumber(displayVideo?.receiver?.latest_capture_to_send_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.networkOneWay') }}:</strong> {{ formatNumber(networkEstimate?.video_network_oneway_est_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.partialEstimate') }}:</strong> {{ formatNumber(networkEstimate?.video_partial_est_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.endToEndEstimate') }}:</strong> {{ formatNumber(networkEstimate?.video_e2e_est_ms, ' ms') }}</p>
       </div>
 
       <div class="metric-group">
-        <h3>Freshness</h3>
-        <p><strong>Inter-frame avg:</strong> {{ formatNumber(freshness?.inter_frame_avg_ms, ' ms') }}</p>
-        <p><strong>Inter-frame p95:</strong> {{ formatNumber(freshness?.inter_frame_p95_ms, ' ms') }}</p>
-        <p><strong>Repeated ratio:</strong> {{ formatNumber((freshness?.repeated_frame_ratio ?? 0) * 100, ' %') }}</p>
-        <p><strong>Skip ratio:</strong> {{ formatNumber((freshness?.skip_ratio ?? 0) * 100, ' %') }}</p>
-        <p><strong>Longest freeze:</strong> {{ formatNumber(freshness?.longest_freeze_ms, ' ms') }}</p>
-        <p><strong>Lag frames:</strong> {{ freshness?.relative_freshness_lag_frames ?? 0 }}</p>
+        <h3>{{ t('videoPanel.section.freshness') }}</h3>
+        <p><strong>{{ t('videoPanel.interFrameAvg') }}:</strong> {{ formatNumber(freshness?.inter_frame_avg_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.interFrameP95') }}:</strong> {{ formatNumber(freshness?.inter_frame_p95_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.repeatedRatio') }}:</strong> {{ formatNumber((freshness?.repeated_frame_ratio ?? 0) * 100, ' %') }}</p>
+        <p><strong>{{ t('videoPanel.skipRatio') }}:</strong> {{ formatNumber((freshness?.skip_ratio ?? 0) * 100, ' %') }}</p>
+        <p><strong>{{ t('videoPanel.longestFreeze') }}:</strong> {{ formatNumber(freshness?.longest_freeze_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.lagFrames') }}:</strong> {{ freshness?.relative_freshness_lag_frames ?? 0 }}</p>
       </div>
 
       <div class="metric-group">
-        <h3>Operator Loop</h3>
-        <p><strong>Input to next seq:</strong> {{ formatNumber(operatorMetrics.input_to_next_fresh_frame_ms, ' ms') }}</p>
-        <p><strong>Input to changed frame:</strong> {{ formatNumber(operatorMetrics.input_to_next_changed_frame_ms, ' ms') }}</p>
-        <p><strong>Input to paint:</strong> {{ formatNumber(operatorMetrics.input_to_next_paint_ms, ' ms') }}</p>
-        <p><strong>Display probe request-to-paint:</strong> {{ formatNumber(displayVideo?.display_probe?.request_to_paint_ms, ' ms') }}</p>
+        <h3>{{ t('videoPanel.section.operator') }}</h3>
+        <p><strong>{{ t('videoPanel.inputToNextSeq') }}:</strong> {{ formatNumber(operatorMetrics.input_to_next_fresh_frame_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.inputToChangedFrame') }}:</strong> {{ formatNumber(operatorMetrics.input_to_next_changed_frame_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.inputToPaint') }}:</strong> {{ formatNumber(operatorMetrics.input_to_next_paint_ms, ' ms') }}</p>
+        <p><strong>{{ t('videoPanel.displayProbeRequestToPaint') }}:</strong> {{ formatNumber(displayVideo?.display_probe?.request_to_paint_ms, ' ms') }}</p>
       </div>
     </div>
 
     <div class="timing-panel">
       <div class="timing-head">
-        <span>Sender Clock Delta</span>
+        <span>{{ t('videoPanel.senderClockDelta') }}</span>
         <strong>{{ timingHeadline }}</strong>
       </div>
       <div class="timing-grid">
@@ -524,7 +525,7 @@ watch(
     </div>
 
     <p class="hint">
-      {{ displayVideo?.source_detail ?? 'no live video detail available' }}
+      {{ displayVideo?.source_detail ?? t('videoPanel.noSourceDetail') }}
     </p>
   </section>
 </template>
diff --git a/frontend/src/composables/useControlInterface.ts b/frontend/src/composables/useControlInterface.ts
index 67fe2a0..40a1747 100644
--- a/frontend/src/composables/useControlInterface.ts
+++ b/frontend/src/composables/useControlInterface.ts
@@ -1,6 +1,7 @@
 import { computed, onMounted, onUnmounted, ref } from 'vue'
 
 import { buildControlWebSocketUrl } from '@/lib/api'
+import { t } from '@/lib/locale'
 
 type SocketState = 'connecting' | 'open' | 'closed'
 type ControlInputMode = 'keyboard' | 'gamepad'
@@ -35,7 +36,7 @@ const KEY_LABELS: Record<string, string> = {
   KeyE: 'E',
   ShiftLeft: 'Shift',
   ShiftRight: 'Shift',
-  Space: 'Stop',
+  Space: 'Space',
 }
 const GAMEPAD_BUTTON_LABELS = ['A', 'B', 'X', 'Y', 'LB', 'RB', 'LT', 'RT', 'Back', 'Start', 'LS', 'RS']
 
@@ -57,10 +58,11 @@ const MAX_TURBO_MULTIPLIER = 3
 
 const pressedKeys = ref<Set<string>>(new Set())
 const socketState = ref<SocketState>('connecting')
-const lastServerMessage = ref('waiting')
+const lastServerMessageOverride = ref('')
+const lastServerMessagePreset = ref<'waiting' | 'live'>('waiting')
 const gamepadSupported = ref(false)
 const gamepadConnected = ref(false)
-const gamepadName = ref('No gamepad detected')
+const gamepadNameRaw = ref('')
 const gamepadIndex = ref<number | null>(null)
 const gamepadMapping = ref('')
 const gamepadAxes = ref<number[]>([0, 0, 0, 0])
@@ -444,7 +446,7 @@ function handleKeyup(event: KeyboardEvent) {
 
 function resetGamepadState() {
   gamepadConnected.value = false
-  gamepadName.value = 'No gamepad detected'
+  gamepadNameRaw.value = ''
   gamepadIndex.value = null
   gamepadMapping.value = ''
   gamepadAxes.value = [0, 0, 0, 0]
@@ -484,9 +486,9 @@ function pollGamepadState() {
 
   lastGamepadSignature = signature
   gamepadConnected.value = true
-  gamepadName.value = pad.id || 'Unnamed gamepad'
+  gamepadNameRaw.value = pad.id || ''
   gamepadIndex.value = pad.index
-  gamepadMapping.value = pad.mapping || 'unknown'
+  gamepadMapping.value = pad.mapping || ''
   gamepadAxes.value = axes
   gamepadButtonPressed.value = buttons
   if (controlInputMode.value === 'gamepad') {
@@ -506,18 +508,21 @@ function connectSocket() {
 
   socket.onopen = () => {
     socketState.value = 'open'
-    lastServerMessage.value = 'control link live'
+    lastServerMessagePreset.value = 'live'
+    lastServerMessageOverride.value = ''
     refreshSendLoop(true, false)
   }
 
   socket.onmessage = (event) => {
     if (typeof event.data === 'string') {
-      lastServerMessage.value = event.data
+      lastServerMessageOverride.value = event.data
     }
   }
 
   socket.onclose = () => {
     socketState.value = 'closed'
+    lastServerMessagePreset.value = 'waiting'
+    lastServerMessageOverride.value = ''
     stopSendLoop()
     socket = null
     if (manualClose) {
@@ -596,20 +601,27 @@ function unmountConsumer() {
 }
 
 const socketLabel = computed(() => {
-  if (socketState.value === 'open') return 'ws open'
-  if (socketState.value === 'connecting') return 'connecting'
-  return 'reconnecting'
+  if (socketState.value === 'open') return t('control.socket.open')
+  if (socketState.value === 'connecting') return t('control.socket.connecting')
+  return t('control.socket.reconnecting')
 })
 
 const activeSourceLabel = computed(() => {
-  if (activeSource.value === 'keyboard') return 'Keyboard'
-  if (activeSource.value === 'gamepad') return 'Gamepad'
-  return 'Idle'
+  if (activeSource.value === 'keyboard') return t('common.keyboard')
+  if (activeSource.value === 'gamepad') return t('common.gamepad')
+  return t('common.idle')
 })
 
 const controlInputModeLabel = computed(() => {
-  if (controlInputMode.value === 'gamepad') return 'Gamepad'
-  return 'Keyboard'
+  if (controlInputMode.value === 'gamepad') return t('common.gamepad')
+  return t('common.keyboard')
+})
+
+const lastServerMessage = computed(() => {
+  if (lastServerMessageOverride.value) {
+    return lastServerMessageOverride.value
+  }
+  return lastServerMessagePreset.value === 'live' ? t('control.server.live') : t('control.server.waiting')
 })
 
 const commandValues = computed(() => {
@@ -635,12 +647,12 @@ const commandMagnitude = computed(() => {
   )
 })
 
-const pressedKeysLabel = computed(() => Array.from(pressedKeys.value).sort().join(', ') || 'none')
+const pressedKeysLabel = computed(() => Array.from(pressedKeys.value).sort().join(', ') || t('common.none'))
 
 const keyboardKeys = computed<KeyFeedback[]>(() =>
   TRACKED_KEYS.map((code) => ({
     code,
-    label: KEY_LABELS[code] ?? code,
+    label: code === 'Space' ? t('control.key.stop') : (KEY_LABELS[code] ?? code),
     pressed: pressedKeys.value.has(code),
   })),
 )
@@ -667,6 +679,13 @@ const gamepadButtons = computed<ButtonFeedback[]>(() =>
   })),
 )
 
+const gamepadName = computed(() => {
+  if (!gamepadConnected.value) {
+    return t('control.gamepad.none')
+  }
+  return gamepadNameRaw.value || t('control.gamepad.unnamed')
+})
+
 const gamepadLeftStick = computed(() => ({
   x: gamepadAxes.value[0] ?? 0,
   y: gamepadAxes.value[1] ?? 0,
diff --git a/frontend/src/composables/useMonitoringData.ts b/frontend/src/composables/useMonitoringData.ts
index 38c1dc3..054cb26 100644
--- a/frontend/src/composables/useMonitoringData.ts
+++ b/frontend/src/composables/useMonitoringData.ts
@@ -1,6 +1,7 @@
 import { computed, onMounted, onUnmounted, ref } from 'vue'
 
 import { fetchDashboardSnapshot } from '@/lib/api'
+import { t } from '@/lib/locale'
 import type { GpsTelemetry, NetworkTelemetry, VideoStatus } from '@/types'
 
 type UseMonitoringDataOptions = {
@@ -25,7 +26,7 @@ export function useMonitoringData(options: UseMonitoringDataOptions = {}) {
       video.value = snapshot.video
       errorMessage.value = ''
     } catch (error) {
-      errorMessage.value = error instanceof Error ? error.message : 'Failed to load monitoring data'
+      errorMessage.value = error instanceof Error ? error.message : t('common.requestFailed', { status: '-', statusText: '' })
     } finally {
       loading.value = false
     }
@@ -36,9 +37,9 @@ export function useMonitoringData(options: UseMonitoringDataOptions = {}) {
       return errorMessage.value
     }
     if (loading.value) {
-      return 'Connecting to the Django backend and loading live monitoring data...'
+      return t('monitoring.loading')
     }
-    return 'Dashboard connected. Video, GPS, and live session telemetry refresh continuously from the unified A-side daemon.'
+    return t('monitoring.connected')
   })
 
   onMounted(() => {
diff --git a/frontend/src/lib/api.ts b/frontend/src/lib/api.ts
index 7dd4d6d..d21b29d 100644
--- a/frontend/src/lib/api.ts
+++ b/frontend/src/lib/api.ts
@@ -1,4 +1,5 @@
 import type { DashboardSnapshot, VideoStatus } from '@/types'
+import { t } from '@/lib/locale'
 
 const envBaseUrl = import.meta.env.VITE_API_BASE_URL as string | undefined
 
@@ -7,7 +8,7 @@ export const API_BASE = (envBaseUrl?.trim() || 'http://127.0.0.1:8001').replace(
 async function fetchJson<T>(path: string): Promise<T> {
   const response = await fetch(`${API_BASE}${path}`)
   if (!response.ok) {
-    throw new Error(`请求失败: ${response.status} ${response.statusText}`)
+    throw new Error(t('common.requestFailed', { status: response.status, statusText: response.statusText }))
   }
   return response.json() as Promise<T>
 }
diff --git a/frontend/src/lib/locale.ts b/frontend/src/lib/locale.ts
new file mode 100644
index 0000000..89c7398
--- /dev/null
+++ b/frontend/src/lib/locale.ts
@@ -0,0 +1,512 @@
+import { computed, readonly, ref } from 'vue'
+
+export type Locale = 'zh-CN' | 'en-US'
+
+const LOCALE_STORAGE_KEY = 'robot-command-center.locale'
+const DEFAULT_LOCALE: Locale = 'zh-CN'
+
+const zhCNMessages = {
+  'common.loading': '加载中',
+  'common.waiting': '等待中',
+  'common.unavailable': '不可用',
+  'common.unknown': '未知',
+  'common.none': '无',
+  'common.na': 'n/a',
+  'common.yes': '是',
+  'common.no': '否',
+  'common.keyboard': '键盘',
+  'common.gamepad': '手柄',
+  'common.idle': '空闲',
+  'common.control': '控制',
+  'common.video': '视频',
+  'common.online': '在线',
+  'common.offline': '离线',
+  'common.fresh': '新鲜',
+  'common.stale': '过期',
+  'common.stable': '稳定',
+  'common.rising': '上升',
+  'common.falling': '下降',
+  'common.selected': '已选中',
+  'common.standby': '待命',
+  'common.turbo': '加速',
+  'common.ackLoop': 'ACK 闭环',
+  'common.srttFallback': 'SRTT 回退',
+  'common.requestFailed': '请求失败: {status} {statusText}',
+  'app.brandTitle': '机器人指挥中心',
+  'app.brandSubtitle': '远程机器人控制台',
+  'app.nav.overview': '概览',
+  'app.nav.video': '视频',
+  'app.nav.map': '地图定位',
+  'app.nav.network': '网络状态',
+  'app.localeToggle': 'English',
+  'dashboard.eyebrow': '概览',
+  'dashboard.title': '机器人指挥中心',
+  'dashboard.description': 'A 端统一后台进程持续刷新视频、控制仲裁和链路遥测。',
+  'networkView.eyebrow': '网络',
+  'networkView.title': '网络遥测',
+  'networkView.description': '查看 A <-> D 与 D <-> B 两段链路的实时队列、重传、窗口压力和延迟估计。',
+  'videoView.eyebrow': '视频',
+  'videoView.title': '视频监控',
+  'videoView.description': '查看机器人实时 JPEG 视频流、画面新鲜度和端到端延迟估计。',
+  'mapView.eyebrow': '地图',
+  'mapView.title': '地图定位',
+  'mapView.description': '查看机器人最新 GPS 数据，并按需使用高德地图做坐标转换和展示。',
+  'monitoring.loading': '正在连接 Django 后端并加载实时监控数据...',
+  'monitoring.connected': '仪表盘已连接。视频、GPS 和会话遥测正在持续刷新。',
+  'control.socket.open': 'WebSocket 已连接',
+  'control.socket.connecting': '连接中',
+  'control.socket.reconnecting': '重连中',
+  'control.server.waiting': '等待控制链路就绪',
+  'control.server.live': '控制链路已建立',
+  'control.gamepad.none': '未检测到手柄',
+  'control.gamepad.unnamed': '未命名手柄',
+  'control.gamepad.unknownMapping': '未知映射',
+  'control.key.stop': '停止',
+  'controlPanel.eyebrow': '控制',
+  'controlPanel.title': '控制反馈',
+  'controlPanel.resetDefaults': '恢复默认',
+  'controlPanel.inputModeEyebrow': '输入模式',
+  'controlPanel.inputModeCopy': '同一时刻只能有一种本地输入模式控制页面。',
+  'controlPanel.keyboardDetail': '使用 W/S、A/D、Q/E、Shift 和 Space。',
+  'controlPanel.gamepadDetail': '仅使用浏览器识别到的手柄。',
+  'controlPanel.forward': '前进',
+  'controlPanel.strafe': '横移',
+  'controlPanel.turn': '转向',
+  'controlPanel.turbo': '加速',
+  'controlPanel.keyboardHint': '键盘映射: W/S 前后, A/D 横移, Q/E 转向, Shift 加速, Space 停止。',
+  'controlPanel.tuningHint': '速度调节由两种本地输入模式共享，并保存在当前浏览器中。',
+  'controlPanel.gamepadHint': '手柄模式下左摇杆控制移动，右摇杆控制转向，RB 加速，A 发送停止。',
+  'controlFeedback.modeChip': '{mode} 模式',
+  'controlFeedback.forward': '前进',
+  'controlFeedback.strafe': '横移',
+  'controlFeedback.turn': '转向',
+  'controlFeedback.tuningSummary': '调参: 前进 {forward} m/s, 横移 {strafe} m/s, 转向 {turn} rad/s, 加速 x{turbo}',
+  'controlFeedback.keyboard': '键盘',
+  'controlFeedback.gamepad': '手柄',
+  'controlFeedback.waitingForController': '等待手柄接入',
+  'controlFeedback.gamepadMeta': '#{index} / 映射={mapping}',
+  'controlFeedback.gamepadHint': '左摇杆控制移动，右摇杆控制转向，RB 加速，A 停止。',
+  'controlFeedback.leftStick': '左摇杆',
+  'controlFeedback.rightStick': '右摇杆',
+  'controlFeedback.outgoingCommand': '当前发出命令: {command}',
+  'videoPanel.eyebrow': '视频',
+  'videoPanel.title': '实时视频',
+  'videoPanel.frameAlt': '机器人实时画面',
+  'videoPanel.waitingFrames': '等待实时视频帧',
+  'videoPanel.mode.loading': '加载中',
+  'videoPanel.mode.live': '{fps} FPS 实时',
+  'videoPanel.stats.frames': '帧数',
+  'videoPanel.stats.latestSeq': '最新序号',
+  'videoPanel.stats.videoE2E': '视频端到端估计',
+  'videoPanel.stats.paintDelay': '绘制延迟',
+  'videoPanel.section.pipeline': '流水线估计',
+  'videoPanel.section.freshness': '新鲜度',
+  'videoPanel.section.operator': '操作员闭环',
+  'videoPanel.captureToSend': '采集到发送',
+  'videoPanel.networkOneWay': '网络单程',
+  'videoPanel.partialEstimate': '部分估计',
+  'videoPanel.endToEndEstimate': '端到端估计',
+  'videoPanel.interFrameAvg': '帧间平均',
+  'videoPanel.interFrameP95': '帧间 p95',
+  'videoPanel.repeatedRatio': '重复比例',
+  'videoPanel.skipRatio': '跳帧比例',
+  'videoPanel.longestFreeze': '最长卡顿',
+  'videoPanel.lagFrames': '落后帧数',
+  'videoPanel.inputToNextSeq': '输入到下一新序号',
+  'videoPanel.inputToChangedFrame': '输入到下一变化帧',
+  'videoPanel.inputToPaint': '输入到下一次绘制',
+  'videoPanel.displayProbeRequestToPaint': '显示探针请求到绘制',
+  'videoPanel.senderClockDelta': '发送端时钟差',
+  'videoPanel.timing.waiting': '等待中',
+  'videoPanel.timing.noTrailer': '正在等待第一帧带有效 trailer 的视频数据',
+  'videoPanel.timing.rawHint': '这里只显示发送端原始时钟差，设备时钟未同步',
+  'videoPanel.noSourceDetail': '暂无实时视频详情',
+  'networkPanel.eyebrow': '网络',
+  'networkPanel.title': '双段链路遥测',
+  'networkPanel.controlLoopRtt': '控制闭环 RTT',
+  'networkPanel.controlToPersist': '控制到持久化',
+  'networkPanel.controlSrttOneWay': '控制单程 SRTT',
+  'networkPanel.videoOneWayEst': '视频单程估计',
+  'networkPanel.txRate': '发送速率',
+  'networkPanel.rxRate': '接收速率',
+  'networkPanel.robotFault': '机器人故障',
+  'networkPanel.recoveryState': '恢复状态',
+  'networkPanel.healthConfidence': '健康置信度',
+  'networkPanel.healthUpdated': '健康更新时间',
+  'networkPanel.transport': '传输',
+  'networkPanel.activeControl': '当前控制源',
+  'networkPanel.lease': '租约',
+  'networkPanel.ackMode': 'ACK 模式',
+  'networkPanel.ackUpdated': 'ACK 更新时间',
+  'networkPanel.telemetryPeer': '遥测 Peer',
+  'networkPanel.telemetryRegistered': '遥测已注册',
+  'networkPanel.hubFreshness': 'Hub 新鲜度',
+  'networkPanel.hubState': 'Hub 状态',
+  'networkPanel.telemetryReconnects': '遥测重连次数',
+  'networkPanel.hubError': 'Hub 错误',
+  'networkPanel.telemetrySessionError': '遥测会话错误',
+  'networkPanel.online': '在线',
+  'networkPanel.maxPressure': '最大压力',
+  'networkPanel.queued': '排队量',
+  'networkPanel.inFlightBuffer': '在途缓冲',
+  'networkPanel.retransDelta': '重传增量',
+  'networkPanel.repairRate': '修复率',
+  'networkPanel.updated': '更新时间',
+  'networkPanel.srtt': 'SRTT',
+  'networkPanel.rttvar': 'RTTVAR',
+  'networkPanel.rto': 'RTO',
+  'networkPanel.sndWnd': '发送窗口',
+  'networkPanel.rmtWnd': '远端窗口',
+  'networkPanel.inflight': '在途',
+  'networkPanel.windowLimit': '窗口上限',
+  'networkPanel.pressure': '压力',
+  'networkPanel.sndQueue': '发送队列',
+  'networkPanel.sndBuffer': '发送缓冲',
+  'networkPanel.queueDelta': '队列增量',
+  'networkPanel.bufferDelta': '缓冲增量',
+  'networkPanel.retrans': '重传',
+  'networkPanel.fastRetrans': '快速重传',
+  'networkPanel.lost': '丢失',
+  'networkPanel.repeat': '重复',
+  'networkPanel.appBytes': '应用字节',
+  'networkPanel.registered': '已注册',
+  'networkPanel.serverError': '服务端错误',
+  'networkPanel.combined': '总计',
+  'networkPanel.videoE2E': '视频端到端估计',
+  'networkPanel.controlEstimateConfidence': '控制估计置信度',
+  'networkPanel.videoFreshness': '视频新鲜度',
+  'networkPanel.videoFreshnessRepeat': '重复',
+  'networkPanel.videoFreshnessSkip': '跳帧',
+  'networkPanel.videoFreshnessFreeze': '卡顿',
+  'networkPanel.nativeUdp': '原生 UDP',
+  'networkPanel.controlSender': '控制发送端',
+  'networkPanel.ackReceiver': 'ACK 接收端',
+  'networkPanel.controlReconnects': '控制重连次数',
+  'networkPanel.controlSessionError': '控制会话错误',
+  'networkPanel.loadingPeer': '加载中',
+  'networkPanel.unassigned': '未分配',
+  'gpsMap.eyebrow': 'GPS',
+  'gpsMap.title': '地图定位',
+  'gpsMap.intro': '这里展示机器人最新的 GPS 定位，并在需要时调用高德地图做坐标转换。',
+  'gpsMap.keyPlaceholder': '高德 Web 端 Key',
+  'gpsMap.jscodePlaceholder': '安全密钥 jscode',
+  'gpsMap.loadMap': '加载地图',
+  'gpsMap.stopMap': '停止加载',
+  'gpsMap.status.waitingInit': '等待加载高德地图。',
+  'gpsMap.status.fillCredentials': '请先填写高德 Key 和安全密钥 jscode。',
+  'gpsMap.status.loading': '正在加载高德地图...',
+  'gpsMap.status.loaded': '地图已加载。',
+  'gpsMap.status.stopped': '已停止高德地图加载与坐标转换。需要时再点击“加载地图”即可。',
+  'gpsMap.status.waitingGps': '等待 GPS 数据。',
+  'gpsMap.status.noFix': 'GPS 在线，但当前还没有有效定位。',
+  'gpsMap.status.convertFailed': 'GPS 坐标转换失败。',
+  'gpsMap.status.refreshedSource': '地图已刷新，数据源: {source}',
+  'gpsMap.status.restoredConfig': '已恢复高德配置。地图不会自动加载，按需点击“加载地图”。',
+  'gpsMap.status.loadFailed': '地图加载失败。',
+  'gpsMap.mapPlaceholder': '高德地图当前未加载。点击上方“加载地图”后才会开始请求地图与坐标转换服务。',
+  'gpsMap.wgs84': 'WGS84 坐标',
+  'gpsMap.gcj02': '高德 GCJ-02',
+  'gpsMap.rawLatHex': '纬度原始 8 字节',
+  'gpsMap.rawLonHex': '经度原始 8 字节',
+  'gpsMap.utcTime': 'UTC 时间',
+  'gpsMap.satAltitude': '卫星 / 海拔',
+  'gpsMap.coordMeta': '坐标系 / 格式',
+  'gpsMap.lastUpdated': '最近刷新',
+  'gpsMap.noValue': '暂无',
+  'gpsMap.noValidFix': '暂无有效定位',
+  'gpsMap.infoTitle': '机器人 GPS 定位',
+  'gpsMap.infoSatellites': '卫星数',
+  'gpsMap.infoAltitude': '海拔',
+} as const
+
+export type MessageKey = keyof typeof zhCNMessages
+
+const enUSMessages: Record<MessageKey, string> = {
+  'common.loading': 'Loading',
+  'common.waiting': 'Waiting',
+  'common.unavailable': 'Unavailable',
+  'common.unknown': 'Unknown',
+  'common.none': 'None',
+  'common.na': 'n/a',
+  'common.yes': 'Yes',
+  'common.no': 'No',
+  'common.keyboard': 'Keyboard',
+  'common.gamepad': 'Gamepad',
+  'common.idle': 'Idle',
+  'common.control': 'Control',
+  'common.video': 'Video',
+  'common.online': 'Online',
+  'common.offline': 'Offline',
+  'common.fresh': 'Fresh',
+  'common.stale': 'Stale',
+  'common.stable': 'Stable',
+  'common.rising': 'Rising',
+  'common.falling': 'Falling',
+  'common.selected': 'Selected',
+  'common.standby': 'Standby',
+  'common.turbo': 'Turbo',
+  'common.ackLoop': 'ACK loop',
+  'common.srttFallback': 'SRTT fallback',
+  'common.requestFailed': 'Request failed: {status} {statusText}',
+  'app.brandTitle': 'Robot Command Center',
+  'app.brandSubtitle': 'Remote robot command console',
+  'app.nav.overview': 'Overview',
+  'app.nav.video': 'Video',
+  'app.nav.map': 'Map',
+  'app.nav.network': 'Network',
+  'app.localeToggle': '中文',
+  'dashboard.eyebrow': 'Overview',
+  'dashboard.title': 'Robot Command Center',
+  'dashboard.description': 'The A-side unified backend keeps video, control arbitration, and live transport telemetry refreshed.',
+  'networkView.eyebrow': 'Network',
+  'networkView.title': 'Network Telemetry',
+  'networkView.description': 'Inspect queueing, retransmissions, window pressure, and latency estimates for the A <-> D and D <-> B legs.',
+  'videoView.eyebrow': 'Video',
+  'videoView.title': 'Video Monitor',
+  'videoView.description': 'Inspect the live robot JPEG stream, freshness metrics, and end-to-end latency estimates.',
+  'mapView.eyebrow': 'Map',
+  'mapView.title': 'Map Positioning',
+  'mapView.description': 'Inspect the latest robot GPS fix and use AMap for coordinate conversion when needed.',
+  'monitoring.loading': 'Connecting to the Django backend and loading live monitoring data...',
+  'monitoring.connected': 'Dashboard connected. Video, GPS, and session telemetry are refreshing continuously.',
+  'control.socket.open': 'WebSocket open',
+  'control.socket.connecting': 'Connecting',
+  'control.socket.reconnecting': 'Reconnecting',
+  'control.server.waiting': 'Waiting for control link',
+  'control.server.live': 'Control link live',
+  'control.gamepad.none': 'No gamepad detected',
+  'control.gamepad.unnamed': 'Unnamed gamepad',
+  'control.gamepad.unknownMapping': 'unknown',
+  'control.key.stop': 'Stop',
+  'controlPanel.eyebrow': 'Control',
+  'controlPanel.title': 'Control Feedback',
+  'controlPanel.resetDefaults': 'Reset Defaults',
+  'controlPanel.inputModeEyebrow': 'Input Mode',
+  'controlPanel.inputModeCopy': 'Only one local input mode can control the page at a time.',
+  'controlPanel.keyboardDetail': 'Use W/S, A/D, Q/E, Shift, and Space.',
+  'controlPanel.gamepadDetail': 'Use the browser-detected controller only.',
+  'controlPanel.forward': 'Forward',
+  'controlPanel.strafe': 'Strafe',
+  'controlPanel.turn': 'Turn',
+  'controlPanel.turbo': 'Turbo',
+  'controlPanel.keyboardHint': 'Keyboard mapping: W/S forward-back, A/D strafe, Q/E turn, Shift turbo, Space stop.',
+  'controlPanel.tuningHint': 'Speed tuning is shared by both local input modes and saved in this browser.',
+  'controlPanel.gamepadHint': 'Gamepad mode uses the left stick to drive, the right stick to turn, RB to boost, and A to stop.',
+  'controlFeedback.modeChip': '{mode} mode',
+  'controlFeedback.forward': 'Forward',
+  'controlFeedback.strafe': 'Strafe',
+  'controlFeedback.turn': 'Turn',
+  'controlFeedback.tuningSummary': 'Tuning: fwd {forward} m/s, strafe {strafe} m/s, turn {turn} rad/s, turbo x{turbo}',
+  'controlFeedback.keyboard': 'Keyboard',
+  'controlFeedback.gamepad': 'Gamepad',
+  'controlFeedback.waitingForController': 'Waiting for controller',
+  'controlFeedback.gamepadMeta': '#{index} / mapping={mapping}',
+  'controlFeedback.gamepadHint': 'Left stick drives, right stick turns, RB boosts, A stops.',
+  'controlFeedback.leftStick': 'Left stick',
+  'controlFeedback.rightStick': 'Right stick',
+  'controlFeedback.outgoingCommand': 'Outgoing command: {command}',
+  'videoPanel.eyebrow': 'Video',
+  'videoPanel.title': 'Live Video',
+  'videoPanel.frameAlt': 'Robot live frame',
+  'videoPanel.waitingFrames': 'waiting for live video frames',
+  'videoPanel.mode.loading': 'loading',
+  'videoPanel.mode.live': '{fps} FPS live',
+  'videoPanel.stats.frames': 'Frames',
+  'videoPanel.stats.latestSeq': 'Latest Seq',
+  'videoPanel.stats.videoE2E': 'Video E2E Est.',
+  'videoPanel.stats.paintDelay': 'Paint Delay',
+  'videoPanel.section.pipeline': 'Pipeline Estimate',
+  'videoPanel.section.freshness': 'Freshness',
+  'videoPanel.section.operator': 'Operator Loop',
+  'videoPanel.captureToSend': 'Capture to send',
+  'videoPanel.networkOneWay': 'Network one-way',
+  'videoPanel.partialEstimate': 'Partial estimate',
+  'videoPanel.endToEndEstimate': 'End-to-end estimate',
+  'videoPanel.interFrameAvg': 'Inter-frame avg',
+  'videoPanel.interFrameP95': 'Inter-frame p95',
+  'videoPanel.repeatedRatio': 'Repeated ratio',
+  'videoPanel.skipRatio': 'Skip ratio',
+  'videoPanel.longestFreeze': 'Longest freeze',
+  'videoPanel.lagFrames': 'Lag frames',
+  'videoPanel.inputToNextSeq': 'Input to next seq',
+  'videoPanel.inputToChangedFrame': 'Input to changed frame',
+  'videoPanel.inputToPaint': 'Input to paint',
+  'videoPanel.displayProbeRequestToPaint': 'Display probe request-to-paint',
+  'videoPanel.senderClockDelta': 'Sender Clock Delta',
+  'videoPanel.timing.waiting': 'waiting',
+  'videoPanel.timing.noTrailer': 'waiting for the first valid video trailer',
+  'videoPanel.timing.rawHint': 'raw sender clock delta only, unsynced clocks',
+  'videoPanel.noSourceDetail': 'no live video detail available',
+  'networkPanel.eyebrow': 'Network',
+  'networkPanel.title': 'Dual-Leg Telemetry',
+  'networkPanel.controlLoopRtt': 'Control Loop RTT',
+  'networkPanel.controlToPersist': 'Control to Persist',
+  'networkPanel.controlSrttOneWay': 'Control SRTT One-way',
+  'networkPanel.videoOneWayEst': 'Video One-way Est.',
+  'networkPanel.txRate': 'TX Rate',
+  'networkPanel.rxRate': 'RX Rate',
+  'networkPanel.robotFault': 'Robot Fault',
+  'networkPanel.recoveryState': 'Recovery State',
+  'networkPanel.healthConfidence': 'Health Confidence',
+  'networkPanel.healthUpdated': 'Health Updated',
+  'networkPanel.transport': 'Transport',
+  'networkPanel.activeControl': 'Active Control',
+  'networkPanel.lease': 'Lease',
+  'networkPanel.ackMode': 'ACK Mode',
+  'networkPanel.ackUpdated': 'ACK Updated',
+  'networkPanel.telemetryPeer': 'Telemetry Peer',
+  'networkPanel.telemetryRegistered': 'Telemetry Registered',
+  'networkPanel.hubFreshness': 'Hub Freshness',
+  'networkPanel.hubState': 'Hub State',
+  'networkPanel.telemetryReconnects': 'Telemetry Reconnects',
+  'networkPanel.hubError': 'Hub Error',
+  'networkPanel.telemetrySessionError': 'Telemetry Session Error',
+  'networkPanel.online': 'Online',
+  'networkPanel.maxPressure': 'Max Pressure',
+  'networkPanel.queued': 'Queued',
+  'networkPanel.inFlightBuffer': 'In Flight Buffer',
+  'networkPanel.retransDelta': 'Retrans Delta',
+  'networkPanel.repairRate': 'Repair Rate',
+  'networkPanel.updated': 'Updated',
+  'networkPanel.srtt': 'SRTT',
+  'networkPanel.rttvar': 'RTTVAR',
+  'networkPanel.rto': 'RTO',
+  'networkPanel.sndWnd': 'SND WND',
+  'networkPanel.rmtWnd': 'RMT WND',
+  'networkPanel.inflight': 'Inflight',
+  'networkPanel.windowLimit': 'Window Limit',
+  'networkPanel.pressure': 'Pressure',
+  'networkPanel.sndQueue': 'SND Queue',
+  'networkPanel.sndBuffer': 'SND Buffer',
+  'networkPanel.queueDelta': 'Queue Delta',
+  'networkPanel.bufferDelta': 'Buffer Delta',
+  'networkPanel.retrans': 'Retrans',
+  'networkPanel.fastRetrans': 'Fast Retrans',
+  'networkPanel.lost': 'Lost',
+  'networkPanel.repeat': 'Repeat',
+  'networkPanel.appBytes': 'App Bytes',
+  'networkPanel.registered': 'Registered',
+  'networkPanel.serverError': 'Server Error',
+  'networkPanel.combined': 'Combined',
+  'networkPanel.videoE2E': 'Video E2E Est.',
+  'networkPanel.controlEstimateConfidence': 'Control Estimate Confidence',
+  'networkPanel.videoFreshness': 'Video Freshness',
+  'networkPanel.videoFreshnessRepeat': 'repeat',
+  'networkPanel.videoFreshnessSkip': 'skip',
+  'networkPanel.videoFreshnessFreeze': 'freeze',
+  'networkPanel.nativeUdp': 'Native UDP',
+  'networkPanel.controlSender': 'Control Sender',
+  'networkPanel.ackReceiver': 'ACK Receiver',
+  'networkPanel.controlReconnects': 'Control Reconnects',
+  'networkPanel.controlSessionError': 'Control Session Error',
+  'networkPanel.loadingPeer': 'loading',
+  'networkPanel.unassigned': 'unassigned',
+  'gpsMap.eyebrow': 'GPS',
+  'gpsMap.title': 'Map Positioning',
+  'gpsMap.intro': 'This panel displays the latest robot GPS fix and uses AMap for coordinate conversion when needed.',
+  'gpsMap.keyPlaceholder': 'AMap Web Key',
+  'gpsMap.jscodePlaceholder': 'Security jscode',
+  'gpsMap.loadMap': 'Load Map',
+  'gpsMap.stopMap': 'Stop Loading',
+  'gpsMap.status.waitingInit': 'Waiting to load AMap.',
+  'gpsMap.status.fillCredentials': 'Please enter the AMap key and security jscode first.',
+  'gpsMap.status.loading': 'Loading AMap...',
+  'gpsMap.status.loaded': 'Map loaded.',
+  'gpsMap.status.stopped': 'Stopped AMap loading and coordinate conversion. Click "Load Map" again when needed.',
+  'gpsMap.status.waitingGps': 'Waiting for GPS data.',
+  'gpsMap.status.noFix': 'GPS is online, but there is no valid fix yet.',
+  'gpsMap.status.convertFailed': 'GPS coordinate conversion failed.',
+  'gpsMap.status.refreshedSource': 'Map refreshed, source: {source}',
+  'gpsMap.status.restoredConfig': 'Recovered saved AMap config. The map will not auto-load; click "Load Map" when needed.',
+  'gpsMap.status.loadFailed': 'Map loading failed.',
+  'gpsMap.mapPlaceholder': 'AMap is not loaded right now. Click "Load Map" above before requesting map and coordinate conversion services.',
+  'gpsMap.wgs84': 'WGS84 Coordinates',
+  'gpsMap.gcj02': 'AMap GCJ-02',
+  'gpsMap.rawLatHex': 'Raw Latitude 8 Bytes',
+  'gpsMap.rawLonHex': 'Raw Longitude 8 Bytes',
+  'gpsMap.utcTime': 'UTC Time',
+  'gpsMap.satAltitude': 'Satellites / Altitude',
+  'gpsMap.coordMeta': 'Coordinate System / Format',
+  'gpsMap.lastUpdated': 'Last Updated',
+  'gpsMap.noValue': 'Unavailable',
+  'gpsMap.noValidFix': 'No valid fix',
+  'gpsMap.infoTitle': 'Robot GPS Position',
+  'gpsMap.infoSatellites': 'Satellites',
+  'gpsMap.infoAltitude': 'Altitude',
+}
+
+const messages: Record<Locale, Record<MessageKey, string>> = {
+  'zh-CN': zhCNMessages,
+  'en-US': enUSMessages,
+}
+
+function normalizeLocale(raw: unknown): Locale {
+  return raw === 'en-US' ? 'en-US' : DEFAULT_LOCALE
+}
+
+function loadStoredLocale(): Locale {
+  if (typeof window === 'undefined') {
+    return DEFAULT_LOCALE
+  }
+  try {
+    return normalizeLocale(window.localStorage.getItem(LOCALE_STORAGE_KEY))
+  } catch {
+    return DEFAULT_LOCALE
+  }
+}
+
+const localeState = ref<Locale>(loadStoredLocale())
+
+function storeLocale(locale: Locale) {
+  if (typeof window === 'undefined') {
+    return
+  }
+  try {
+    window.localStorage.setItem(LOCALE_STORAGE_KEY, locale)
+  } catch {
+    // Ignore storage failures; locale still works for current session.
+  }
+}
+
+function interpolate(template: string, params?: Record<string, string | number | null | undefined>) {
+  if (!params) {
+    return template
+  }
+  return template.replace(/\{(\w+)\}/g, (_, key: string) => String(params[key] ?? ''))
+}
+
+export function t(key: MessageKey, params?: Record<string, string | number | null | undefined>) {
+  const template = messages[localeState.value][key] ?? key
+  return interpolate(template, params)
+}
+
+export function formatDateTime(value?: string | null) {
+  if (!value) {
+    return t('common.unavailable')
+  }
+  return new Date(value).toLocaleString(localeState.value, { hour12: false })
+}
+
+export function setLocale(locale: Locale) {
+  const next = normalizeLocale(locale)
+  if (localeState.value === next) {
+    return
+  }
+  localeState.value = next
+  storeLocale(next)
+}
+
+export function toggleLocale() {
+  setLocale(localeState.value === 'zh-CN' ? 'en-US' : 'zh-CN')
+}
+
+export function useLocale() {
+  return {
+    locale: readonly(localeState),
+    setLocale,
+    toggleLocale,
+    t,
+    formatDateTime,
+    nextLocaleLabel: computed(() => t('app.localeToggle')),
+  }
+}
diff --git a/frontend/src/views/DashboardView.vue b/frontend/src/views/DashboardView.vue
index f38dbef..1aad0bb 100644
--- a/frontend/src/views/DashboardView.vue
+++ b/frontend/src/views/DashboardView.vue
@@ -3,6 +3,7 @@ import ControlPanel from '@/components/ControlPanel.vue'
 import GpsMapPanel from '@/components/GpsMapPanel.vue'
 import NetworkPanel from '@/components/NetworkPanel.vue'
 import VideoPanel from '@/components/VideoPanel.vue'
+import { t } from '@/lib/locale'
 import { useMonitoringData } from '@/composables/useMonitoringData'
 
 const { gps, network, video, errorMessage, headerStatus } = useMonitoringData()
@@ -12,13 +13,10 @@ const { gps, network, video, errorMessage, headerStatus } = useMonitoringData()
   <div class="page-shell">
     <header class="hero">
       <div>
-        <p class="eyebrow">Overview</p>
-        <h1>Robot Command Center</h1>
+        <p class="eyebrow">{{ t('dashboard.eyebrow') }}</p>
+        <h1>{{ t('dashboard.title') }}</h1>
       </div>
-      <p class="hero-text">
-        The A-side daemon now owns video receive, control ingress arbitration, and live session
-        telemetry in one backend process.
-      </p>
+      <p class="hero-text">{{ t('dashboard.description') }}</p>
     </header>
 
     <section class="banner" :class="{ error: !!errorMessage }">
diff --git a/frontend/src/views/MapView.vue b/frontend/src/views/MapView.vue
index 42f8da7..316db32 100644
--- a/frontend/src/views/MapView.vue
+++ b/frontend/src/views/MapView.vue
@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import GpsMapPanel from '@/components/GpsMapPanel.vue'
+import { t } from '@/lib/locale'
 import { useMonitoringData } from '@/composables/useMonitoringData'
 
 const { gps, errorMessage, headerStatus } = useMonitoringData({
@@ -11,13 +12,10 @@ const { gps, errorMessage, headerStatus } = useMonitoringData({
   <div class="page-shell">
     <header class="page-header">
       <div>
-        <p class="eyebrow">Map</p>
-        <h1>地图定位页面</h1>
+        <p class="eyebrow">{{ t('mapView.eyebrow') }}</p>
+        <h1>{{ t('mapView.title') }}</h1>
       </div>
-      <p class="description">
-        这里整合了 `GeoStream` 的 GPS 展示逻辑。只要原来的 GPS 模块继续写
-        `gps_latest.json`，这个页面就能直接显示实时定位。
-      </p>
+      <p class="description">{{ t('mapView.description') }}</p>
     </header>
 
     <section class="banner" :class="{ error: !!errorMessage }">
diff --git a/frontend/src/views/NetworkView.vue b/frontend/src/views/NetworkView.vue
index b4ce4a0..c89eb3f 100644
--- a/frontend/src/views/NetworkView.vue
+++ b/frontend/src/views/NetworkView.vue
@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import NetworkPanel from '@/components/NetworkPanel.vue'
+import { t } from '@/lib/locale'
 import { useMonitoringData } from '@/composables/useMonitoringData'
 
 const { network, errorMessage, headerStatus } = useMonitoringData({
@@ -11,14 +12,10 @@ const { network, errorMessage, headerStatus } = useMonitoringData({
   <div class="page-shell">
     <header class="page-header">
       <div>
-        <p class="eyebrow">Network</p>
-        <h1>Network Telemetry</h1>
+        <p class="eyebrow">{{ t('networkView.eyebrow') }}</p>
+        <h1>{{ t('networkView.title') }}</h1>
       </div>
-      <p class="description">
-        Live dual-leg OmniSocket telemetry from the A-side daemon, separating the local `A <-> D`
-        sessions from the hub-reported `D <-> B` leg with queue pressure, retransmission, and stale-link
-        visibility.
-      </p>
+      <p class="description">{{ t('networkView.description') }}</p>
     </header>
 
     <section class="banner" :class="{ error: !!errorMessage }">
diff --git a/frontend/src/views/VideoView.vue b/frontend/src/views/VideoView.vue
index 0c21a1e..b9806ab 100644
--- a/frontend/src/views/VideoView.vue
+++ b/frontend/src/views/VideoView.vue
@@ -1,5 +1,6 @@
 <script setup lang="ts">
 import VideoPanel from '@/components/VideoPanel.vue'
+import { t } from '@/lib/locale'
 import { useMonitoringData } from '@/composables/useMonitoringData'
 
 const { video, network, errorMessage, headerStatus } = useMonitoringData()
@@ -9,10 +10,10 @@ const { video, network, errorMessage, headerStatus } = useMonitoringData()
   <div class="page-shell">
     <header class="page-header">
       <div>
-        <p class="eyebrow">Video</p>
-        <h1>视频流页面</h1>
+        <p class="eyebrow">{{ t('videoView.eyebrow') }}</p>
+        <h1>{{ t('videoView.title') }}</h1>
       </div>
-      <p class="description">这个页面专门用于看逐帧 JPEG 画面。前端会按固定频率请求单张 JPEG，后端每次返回一帧。</p>
+      <p class="description">{{ t('videoView.description') }}</p>
     </header>
 
     <section class="banner" :class="{ error: !!errorMessage }">