diff --git a/controllers/aboutUsController.js b/controllers/aboutUsController.js
index 9a4211a..847cacb 100644
--- a/controllers/aboutUsController.js
+++ b/controllers/aboutUsController.js
@@ -253,7 +253,7 @@ exports.getAbout = async (req, res) => {
     // ===============================
 
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(rawData, baseUrl);
 
     res.json(processedData);
diff --git a/controllers/activityController.js b/controllers/activityController.js
index dc1f9f0..4db7997 100644
--- a/controllers/activityController.js
+++ b/controllers/activityController.js
@@ -25,7 +25,7 @@ exports.api = async (req, res) => {
   try {
     // Return structured response with filters and camps
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
 
     // Get filters document (single doc with isFiltersDoc:true)
     const filtersDoc = await Activity.findOne({ isFiltersDoc: true }).lean();
@@ -69,7 +69,7 @@ exports.apiDetail = async (req, res) => {
     }
 
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processed = addBaseUrlToImages(activity, baseUrl);
 
     return res.json(processed);
@@ -618,7 +618,7 @@ exports.preview = async (req, res) => {
     }
 
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processed = addBaseUrlToImages(activity, baseUrl);
 
     res.json(processed);
diff --git a/controllers/blogController.js b/controllers/blogController.js
index dbe89ea..d6ceeec 100644
--- a/controllers/blogController.js
+++ b/controllers/blogController.js
@@ -445,7 +445,7 @@ exports.api = async (req, res) => {
 
     // Add base URL to images
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedBlogs = blogs.map((blog) =>
       addBaseUrlToImages(blog, baseUrl),
     );
@@ -515,7 +515,7 @@ exports.apiShow = async (req, res) => {
 
     // Add base URL to images
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedBlog = addBaseUrlToImages(blog, baseUrl);
 
     res.json({
@@ -662,7 +662,7 @@ exports.apiRecent = async (req, res) => {
 
     // Add base URL to images
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedPosts = recentPosts.map((post) =>
       addBaseUrlToImages(post, baseUrl),
     );
diff --git a/controllers/contactController.js b/controllers/contactController.js
index ecd4ea3..a1c3c28 100644
--- a/controllers/contactController.js
+++ b/controllers/contactController.js
@@ -22,7 +22,7 @@ exports.api = async (req, res) => {
       return res.status(404).json({ error: "Contact data not found" });
     }
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(contact, baseUrl);
     res.json(processedData);
   } catch (err) {
diff --git a/controllers/homeController.js b/controllers/homeController.js
index 5f8bc22..6f9ccfd 100644
--- a/controllers/homeController.js
+++ b/controllers/homeController.js
@@ -445,10 +445,9 @@ exports.apiGetBlogs = async (req, res) => {
 };
 exports.api = async (req, res) => {
   try {
-    // Chỉ dùng doc mới nhất, không merge nhiều docs
-    const doc = await getHomeDoc();
-    let data = doc?.toObject() || {};
-    const baseUrl = `${req.protocol}://${req.get("host")}`;
+    let data = await getHomeData();
+    const baseUrl =
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
 
     // === Xử lý Blog Preview động ===
     const blogPreview = data.blogPreview || {};
diff --git a/controllers/insuranceController.js b/controllers/insuranceController.js
index ba4a790..5978dbd 100644
--- a/controllers/insuranceController.js
+++ b/controllers/insuranceController.js
@@ -17,7 +17,7 @@ exports.api = async (req, res) => {
 
     // Sử dụng helper để thêm base URL vào đường dẫn ảnh
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(insuranceData, baseUrl);
 
     // Trả về trực tiếp hero, page, content (không wrap trong object)
@@ -56,7 +56,7 @@ exports.getInsuranceData = async (req, res) => {
 
     // Thêm base URL vào đường dẫn ảnh
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(insuranceData, baseUrl);
 
     res.json({
@@ -93,7 +93,7 @@ exports.getByLanguage = async (req, res) => {
 
     // Thêm base URL vào đường dẫn ảnh
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(insuranceData, baseUrl);
 
     res.json({
@@ -196,7 +196,7 @@ exports.preview = async (req, res) => {
 
     // Thêm base URL vào đường dẫn ảnh cho preview
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedHeroData = addBaseUrlToImages(heroData, baseUrl);
 
     // Render preview HTML
diff --git a/controllers/safetyController.js b/controllers/safetyController.js
index 953faa6..1cf4315 100644
--- a/controllers/safetyController.js
+++ b/controllers/safetyController.js
@@ -21,7 +21,7 @@ exports.api = async (req, res) => {
       return res.status(404).json({ error: "Safety data not found" });
     }
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(safety, baseUrl);
     res.json(processedData);
   } catch (err) {
diff --git a/controllers/serviceController.js b/controllers/serviceController.js
index 9cf24a0..9b11b72 100644
--- a/controllers/serviceController.js
+++ b/controllers/serviceController.js
@@ -253,7 +253,7 @@ exports.api = async (req, res) => {
   try {
     const serviceData = await getServiceData();
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
 
     const processedData = addBaseUrlToImages(serviceData, baseUrl);
     res.json(processedData);
@@ -291,7 +291,7 @@ exports.getServiceBySlug = async (req, res) => {
     }
 
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
 
     // Return service details in the expected format
     const responseData = {
diff --git a/controllers/termsController.js b/controllers/termsController.js
index 79bd924..e170790 100644
--- a/controllers/termsController.js
+++ b/controllers/termsController.js
@@ -19,7 +19,7 @@ exports.api = async (req, res) => {
     // Sử dụng helper để thêm base URL vào đường dẫn ảnh
     // Truyền baseUrl từ request hoặc từ environment
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(termsData, baseUrl);
 
     res.json({
@@ -57,7 +57,7 @@ exports.getTermsData = async (req, res) => {
 
     // Thêm base URL vào đường dẫn ảnh
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(termsData, baseUrl);
 
     res.json({
@@ -91,7 +91,7 @@ exports.getByLanguage = async (req, res) => {
 
     // Thêm base URL vào đường dẫn ảnh
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(termsData, baseUrl);
 
     res.json({
@@ -326,7 +326,7 @@ exports.preview = async (req, res) => {
 
     // Thêm base URL vào đường dẫn ảnh cho preview
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedHeroData = addBaseUrlToImages(heroData, baseUrl);
 
     // Render preview HTML
diff --git a/controllers/travelController.js b/controllers/travelController.js
index 834dde8..f4e6592 100644
--- a/controllers/travelController.js
+++ b/controllers/travelController.js
@@ -179,7 +179,7 @@ exports.api = exports.getTravelData = async (req, res) => {
 
     const travelObj = travel.toObject();
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processed = addBaseUrlToImages(travelObj, baseUrl);
 
     return res.json({
diff --git a/controllers/videoGalleryController.js b/controllers/videoGalleryController.js
index 7487812..c18297a 100644
--- a/controllers/videoGalleryController.js
+++ b/controllers/videoGalleryController.js
@@ -23,7 +23,7 @@ exports.api = async (req, res) => {
       return res.status(404).json({ error: "Video Gallery data not found" });
     }
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(videoGallery, baseUrl);
     res.json(processedData);
   } catch (err) {
diff --git a/controllers/visaController.js b/controllers/visaController.js
index d20aa1c..61d1899 100644
--- a/controllers/visaController.js
+++ b/controllers/visaController.js
@@ -678,7 +678,7 @@ exports.apiHero = async (req, res) => {
     );
 
     const baseUrl =
-      process.env.BACKEND_URL || `${req.protocol}://${req.get("host")}`;
+      process.env.BACKEND_URL ?? `${req.protocol}://${req.get("host")}`;
     const processedData = addBaseUrlToImages(heroData, baseUrl);
 
     return res.json({