diff --git a/admin/src/utils/liveWebRTC.js b/admin/src/utils/liveWebRTC.js
index b32deff..b44401d 100644
--- a/admin/src/utils/liveWebRTC.js
+++ b/admin/src/utils/liveWebRTC.js
@@ -57,6 +57,14 @@ function liveWsURLPublish(token) {
 
 const defaultIce = [{ urls: 'stun:stun.l.google.com:19302' }]
 
+const MAX_SIGNAL_RECONNECT = 15
+
+function healthCheckUrl() {
+  if (apiBase) return `${apiBase}/api/health`
+  if (typeof window !== 'undefined') return `${window.location.origin}/api/health`
+  return '/api/health'
+}
+
 function buildCameraConstraints(publishKey, videoDeviceId) {
   const preset = QUALITY_MEDIA[publishKey] || QUALITY_MEDIA.source
   const dev = videoDeviceId ? { deviceId: { exact: videoDeviceId } } : {}
@@ -130,6 +138,7 @@ export function startPublishing(opts = {}) {
   let reconnectTimer = null
   let reconnectAttempt = 0
   let wsGen = 0
+  let reconnectStopped = false
 
   function clearReconnectTimer() {
     if (reconnectTimer) {
@@ -254,20 +263,36 @@ export function startPublishing(opts = {}) {
   }
 
   function scheduleReconnect() {
-    if (closedByLocal) return
+    if (closedByLocal || reconnectStopped) return
     clearReconnectTimer()
-    const delay = Math.min(2000 * Math.pow(1.45, reconnectAttempt), 28000)
     reconnectAttempt += 1
-    onStatus(`信令断开，${Math.round(delay / 1000)} 秒后重连（${reconnectAttempt}）…`)
-    reconnectTimer = window.setTimeout(() => {
+    if (reconnectAttempt > MAX_SIGNAL_RECONNECT) {
+      reconnectStopped = true
+      onStatus(
+        `信令已重试 ${MAX_SIGNAL_RECONNECT} 次仍失败。多为 API 返回 502（进程未启动/崩溃）或 Nginx 未正确反代到 Go。请检查服务与 \`/api/web/live/ws\` 的 WebSocket 配置，修复后刷新本页再点「开始直播」。`
+      )
+      return
+    }
+    const delay = Math.min(2000 * Math.pow(1.45, reconnectAttempt - 1), 28000)
+    onStatus(`信令断开，约 ${Math.round(delay / 1000)} 秒后重试（${reconnectAttempt}/${MAX_SIGNAL_RECONNECT}）…`)
+    reconnectTimer = window.setTimeout(async () => {
       reconnectTimer = null
-      if (closedByLocal) return
+      if (closedByLocal || reconnectStopped) return
+      try {
+        const r = await fetch(healthCheckUrl(), { method: 'GET', cache: 'no-store' })
+        if (!r.ok) {
+          onStatus(`API 不可用（HTTP ${r.status}），多为网关 502，推迟重试…`)
+        }
+      } catch (_) {
+        onStatus('无法访问健康检查接口，请确认网络与域名。')
+      }
+      if (closedByLocal || reconnectStopped) return
       openSignalingSocket()
     }, delay)
   }
 
   function openSignalingSocket() {
-    if (closedByLocal) return
+    if (closedByLocal || reconnectStopped) return
     const myGen = ++wsGen
     clearReconnectTimer()
     if (ws) {
@@ -321,6 +346,7 @@ export function startPublishing(opts = {}) {
 
   function stop() {
     closedByLocal = true
+    reconnectStopped = true
     wsGen += 1
     clearReconnectTimer()
     if (ws) {
diff --git a/admin/src/views/sites/LiveBroadcast.vue b/admin/src/views/sites/LiveBroadcast.vue
index 5387cae..1b300ae 100644
--- a/admin/src/views/sites/LiveBroadcast.vue
+++ b/admin/src/views/sites/LiveBroadcast.vue
@@ -133,7 +133,7 @@ onBeforeRouteLeave(() => {
 
 <style scoped>
 .live-broadcast {
-  max-width: 720px;
+  max-width: min(1200px, 100%);
 }
 .status {
   color: #409eff;
@@ -160,21 +160,23 @@ onBeforeRouteLeave(() => {
 }
 .preview-wrap {
   position: relative;
-  max-width: 720px;
+  width: 100%;
+  max-width: 1100px;
 }
 .preview-main {
   display: block;
   width: 100%;
-  max-height: 70vh;
+  min-height: 320px;
+  max-height: min(85vh, 900px);
   border-radius: 8px;
   background: #000;
   object-fit: contain;
 }
 .preview-pip {
   position: absolute;
-  right: 12px;
-  bottom: 12px;
-  width: min(28%, 200px);
+  right: 14px;
+  bottom: 14px;
+  width: min(32%, 280px);
   aspect-ratio: 4 / 3;
   border-radius: 8px;
   border: 2px solid #409eff;