diff --git a/.env.example b/.env.example
index 8575ca4..2ef9dd0 100644
--- a/.env.example
+++ b/.env.example
@@ -1,3 +1,16 @@
+# vite / vite dev：預設 mode = development
+# vite build：預設 mode = production
+# vite --mode staging：改成 staging
+# vite build --mode development：build 但用 development mode
+
+# 覆蓋優先從低至高
+# .env
+# .env.local
+# .env.[mode]
+# .env.[mode].local
+
+
+
 # Vite dev proxy 目標後端 URL。
 VITE_PROXY_TARGET=http://192.168.89.54:9002
 
diff --git a/vite.config.mts b/vite.config.mts
index c543b4b..7c88626 100644
--- a/vite.config.mts
+++ b/vite.config.mts
@@ -1,10 +1,13 @@
 import { fileURLToPath, URL } from 'node:url'
 import Vue from '@vitejs/plugin-vue'
-import { defineConfig } from 'vite'
+import { defineConfig, loadEnv } from 'vite'
 import Vuetify, { transformAssetUrls } from 'vite-plugin-vuetify'
 
 // https://vitejs.dev/config/
-export default defineConfig({
+export default defineConfig(({ mode }) => {
+  const env = loadEnv(mode, process.cwd(), '')
+
+  return {
   plugins: [
     Vue({
       template: { transformAssetUrls },
@@ -36,7 +39,7 @@ export default defineConfig({
     port: 3700,
     proxy:{
       "/service/": {
-        target: process.env.VITE_PROXY_TARGET || "http://localhost:8080",
+        target: env.VITE_PROXY_TARGET || "http://localhost:8080",
         changeOrigin: true,
       },
     }
@@ -47,4 +50,4 @@ export default defineConfig({
       },
     },
   },
-})
+}})