diff --git a/backend/app/Services/AiInteractiveLabGeneratorService.php b/backend/app/Services/AiInteractiveLabGeneratorService.php
index 32d14e8..24fea49 100644
--- a/backend/app/Services/AiInteractiveLabGeneratorService.php
+++ b/backend/app/Services/AiInteractiveLabGeneratorService.php
@@ -118,7 +118,7 @@ PROMPT;
      */
     private static function callGemini(string $apiKey, string $prompt): string
     {
-        $model = 'gemini-2.0-flash';
+        $model = Env::get('GEMINI_MODEL') ?: 'gemini-flash-lite-latest';
         $url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent?key={$apiKey}";
 
         $payload = [
@@ -164,7 +164,7 @@ PROMPT;
 
     private static function callGeminiFallback(string $apiKey, string $prompt): string
     {
-        $model = 'gemini-1.5-flash';
+        $model = Env::get('GEMINI_MODEL') ?: 'gemini-flash-lite-latest';
         $url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent?key={$apiKey}";
 
         $payload = [
diff --git a/backend/app/Services/AiLessonEnhancerService.php b/backend/app/Services/AiLessonEnhancerService.php
index e996b5d..408d400 100644
--- a/backend/app/Services/AiLessonEnhancerService.php
+++ b/backend/app/Services/AiLessonEnhancerService.php
@@ -122,7 +122,7 @@ class AiLessonEnhancerService
         $keys = explode(',', $apiKey);
         $apiKey = trim($keys[0]);
 
-        $model = Env::get('GEMINI_MODEL') ?: 'gemini-1.5-flash';
+        $model = Env::get('GEMINI_MODEL') ?: 'gemini-flash-lite-latest';
         $url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent?key={$apiKey}";
 
         $payload = [
diff --git a/backend/app/Services/AiQuestionBankGeneratorService.php b/backend/app/Services/AiQuestionBankGeneratorService.php
index faeb6e0..d5d82ea 100644
--- a/backend/app/Services/AiQuestionBankGeneratorService.php
+++ b/backend/app/Services/AiQuestionBankGeneratorService.php
@@ -253,7 +253,7 @@ class AiQuestionBankGeneratorService
 
         $keys = explode(',', $apiKey);
         $apiKey = trim($keys[0]);
-        $model = Env::get('GEMINI_MODEL') ?: 'gemini-1.5-flash';
+        $model = Env::get('GEMINI_MODEL') ?: 'gemini-flash-lite-latest';
         $url = "https://generativelanguage.googleapis.com/v1beta/models/{$model}:generateContent?key={$apiKey}";
 
         $payload = [
diff --git a/backend/app/Services/AiVideoAnalyzerService.php b/backend/app/Services/AiVideoAnalyzerService.php
index 87e7795..749f43e 100644
--- a/backend/app/Services/AiVideoAnalyzerService.php
+++ b/backend/app/Services/AiVideoAnalyzerService.php
@@ -123,7 +123,7 @@ class AiVideoAnalyzerService
                 ]],
                 'generationConfig' => ['responseMimeType' => 'application/json', 'temperature' => 0.1],
             ];
-            $geminiModel = getenv('GEMINI_MODEL') ?: 'gemini-1.5-flash';
+            $geminiModel = getenv('GEMINI_MODEL') ?: 'gemini-flash-lite-latest';
             $ch = curl_init('https://generativelanguage.googleapis.com/v1beta/models/' . rawurlencode($geminiModel) . ':generateContent?key=' . rawurlencode($key));
             curl_setopt_array($ch, [
                 CURLOPT_POST => true,
@@ -329,7 +329,7 @@ class AiVideoAnalyzerService
   \"approval_status\": \"approved_official\"
 }";
 
-                $geminiModel = getenv('GEMINI_MODEL') ?: 'gemini-1.5-flash';
+                $geminiModel = getenv('GEMINI_MODEL') ?: 'gemini-flash-lite-latest';
                 $url = "https://generativelanguage.googleapis.com/v1beta/models/" . rawurlencode($geminiModel) . ":generateContent?key=" . $geminiKey;
                 $payload = [
                     'contents' => [['parts' => [['text' => $prompt]]]],
@@ -445,7 +445,7 @@ class AiVideoAnalyzerService
 }
 قاعدة صارمة: السؤال عند أي دقيقة يسأل فقط عما تم شرحه قبل ذلك التوقيت، وممنوع نهائياً الاستعانة بأي معلومة خارج المنهاج.";
 
-                $geminiModel = getenv('GEMINI_MODEL') ?: 'gemini-1.5-flash';
+                $geminiModel = getenv('GEMINI_MODEL') ?: 'gemini-flash-lite-latest';
                 $url = "https://generativelanguage.googleapis.com/v1beta/models/" . rawurlencode($geminiModel) . ":generateContent?key=" . $geminiKey;
                 $payload = [
                     'contents' => [
diff --git a/backend/scripts/curriculum_worker.php b/backend/scripts/curriculum_worker.php
index a45088c..96a58c0 100644
--- a/backend/scripts/curriculum_worker.php
+++ b/backend/scripts/curriculum_worker.php
@@ -185,7 +185,7 @@ sleep(4);
 // Allow custom model from .env (e.g. gemini-1.5-flash or gemini-2.0-flash)
 $geminiModel = Env::get('GEMINI_MODEL') ?: getenv('GEMINI_MODEL');
 if (empty($geminiModel)) {
-    $geminiModel = "gemini-1.5-flash"; // standard robust model
+    $geminiModel = "gemini-flash-lite-latest";
 }
 updateState($stateFile, 'analyzing', 75, "جاري إرسال البيانات للنموذج [{$geminiModel}] لاستخراج الدروس والمفاهيم والمعادلات...");
 $url = "https://generativelanguage.googleapis.com/v1beta/models/{$geminiModel}:generateContent?key=" . $geminiKey;