cors

frontend/src/services/api.js

@@ -1,6 +1,18 @@
 import axios from 'axios';
 
-const API_URL = import.meta.env.VITE_API_URL || 'http://localhost:3000';
+const resolveApiUrl = () => {
+  if (import.meta.env.VITE_API_URL) {
+    return import.meta.env.VITE_API_URL;
+  }
+
+  if (typeof window !== 'undefined' && window.location?.origin) {
+    return window.location.origin;
+  }
+
+  return 'http://localhost:3000';
+};
+
+const API_URL = resolveApiUrl();
 
 const api = axios.create({
   baseURL: API_URL,