diff --git a/.gitattributes b/.gitattributes
index 42d4987..8579a1d 100644
--- a/.gitattributes
+++ b/.gitattributes
@@ -1,4 +1,5 @@
 # Zorg dat omgevingsspecifieke bestanden nooit worden overschreven bij merges tussen dev en main
 config/config.php merge=ours
 includes/env_badge.php merge=ours
+config/.env.example merge=ours
 
diff --git a/README.md b/README.md
index c2b8d66..ab3f850 100644
--- a/README.md
+++ b/README.md
@@ -81,7 +81,7 @@ DB_PORT="3306"
 DB_NAME="fociz"
 DB_USER="uw_mariadb_gebruiker"
 DB_PASS="uw_mariadb_wachtwoord"
-APP_URL="https://uw-domein.nl"
+APP_URL="https://fociz.nl"
 ```
 
 ### 3. Automatische Tabellen Aanmaak
@@ -90,7 +90,7 @@ U hoeft **niet** handmatig SQL-commando's uit te voeren: zodra u de website voor
 *(Optioneel kunt u `config/schema.sql` ook zelf importeren via phpMyAdmin of de MariaDB CLI).*
 
 ### 4. Eerste Beheerder Instellen
-1. Open uw browser en ga naar `https://uw-domein.nl`.
+1. Open uw browser en ga naar `https://fociz.nl` (of `https://dev.fociz.nl`).
 2. U wordt automatisch doorverwezen naar `/auth/setup.php`.
 3. Vul uw naam, e-mailadres en gewenst wachtwoord in.
 4. Scan de QR-code met Google Authenticator of Microsoft Authenticator.
diff --git a/config/.env.example b/config/.env.example
index b767f64..9c95a8a 100644
--- a/config/.env.example
+++ b/config/.env.example
@@ -8,8 +8,8 @@ DB_PASS="F0c1z_Dev_Secure_2026!"
 # Omgeving: 'development' (knippert rood) of 'live' (knippert groen)
 APP_ENV="development"
 
-# Applicatie URL (voor uitnodigingslinks)
-APP_URL="https://uw-domein.nl"
+# Applicatie URL (voor uitnodigingslinks en OAuth redirects: https://dev.fociz.nl of https://fociz.nl)
+APP_URL="https://dev.fociz.nl"
 
 # Applicatie Geheime Sleutel (willekeurige tekenreeks)
 APP_SECRET="fociz-maria-db-super-secret-key-998877"
diff --git a/config/config.php b/config/config.php
index aa7d32d..d64fe28 100644
--- a/config/config.php
+++ b/config/config.php
@@ -73,11 +73,36 @@ define('DB_USER', fociz_env('DB_USER', 'root'));
 define('DB_PASS', fociz_env('DB_PASS', ''));
 define('DB_CHARSET', 'utf8mb4');
 
+// Bepaal de dynamische of geconfigureerde applicatie URL
+if (!function_exists('fociz_detect_app_url')) {
+    function fociz_detect_app_url(): string {
+        $envUrl = fociz_env('APP_URL');
+        if (!empty($envUrl) && !str_contains($envUrl, 'uw-domein.nl')) {
+            return rtrim($envUrl, '/');
+        }
+
+        // Dynamische detectie op basis van het huidige domein (werkt direct op dev.fociz.nl én fociz.nl)
+        if (!empty($_SERVER['HTTP_HOST'])) {
+            $isHttps = (
+                (!empty($_SERVER['HTTPS']) && $_SERVER['HTTPS'] !== 'off') ||
+                (!empty($_SERVER['HTTP_X_FORWARDED_PROTO']) && strtolower($_SERVER['HTTP_X_FORWARDED_PROTO']) === 'https') ||
+                (!empty($_SERVER['HTTP_X_FORWARDED_SSL']) && $_SERVER['HTTP_X_FORWARDED_SSL'] === 'on') ||
+                (isset($_SERVER['SERVER_PORT']) && (int)$_SERVER['SERVER_PORT'] === 443)
+            );
+            $scheme = $isHttps ? 'https://' : 'http://';
+            return $scheme . $_SERVER['HTTP_HOST'];
+        }
+
+        // Standaard fallback per omgeving
+        return (defined('APP_ENV') && APP_ENV === 'live') ? 'https://fociz.nl' : 'https://dev.fociz.nl';
+    }
+}
+
 // Applicatie instellingen
 define('APP_NAME', 'Fociz');
-define('APP_URL', fociz_env('APP_URL', ((isset($_SERVER['HTTPS']) && $_SERVER['HTTPS'] === 'on' ? 'https://' : 'http://') . ($_SERVER['HTTP_HOST'] ?? 'localhost'))));
-define('APP_SECRET', fociz_env('APP_SECRET', 'fociz-maria-db-super-secret-key-998877'));
 define('APP_ENV', fociz_env('APP_ENV', 'development')); // 'development' of 'live'
+define('APP_URL', fociz_detect_app_url());
+define('APP_SECRET', fociz_env('APP_SECRET', 'fociz-maria-db-super-secret-key-998877'));
 
 // Tijdzone
 date_default_timezone_set('Europe/Amsterdam');