diff --git a/components/AICoach.tsx b/components/AICoach.tsx
index 25c667e..6bc4c95 100644
--- a/components/AICoach.tsx
+++ b/components/AICoach.tsx
@@ -29,7 +29,7 @@ const AICoach: React.FC<AICoachProps> = ({ history, lang }) => {
 
   useEffect(() => {
     try {
-      const chat = createFitnessChat(history);
+      const chat = createFitnessChat(history, lang);
       if (chat) {
         chatSessionRef.current = chat;
       } else {
@@ -108,8 +108,8 @@ const AICoach: React.FC<AICoachProps> = ({ history, lang }) => {
         {messages.map((msg) => (
           <div key={msg.id} className={`flex ${msg.role === 'user' ? 'justify-end' : 'justify-start'}`}>
             <div className={`max-w-[85%] p-4 rounded-[20px] text-sm leading-relaxed shadow-sm ${msg.role === 'user'
-                ? 'bg-primary text-on-primary rounded-br-none'
-                : 'bg-surface-container-high text-on-surface border border-outline-variant/20 rounded-bl-none'
+              ? 'bg-primary text-on-primary rounded-br-none'
+              : 'bg-surface-container-high text-on-surface border border-outline-variant/20 rounded-bl-none'
               }`}>
               {msg.text}
             </div>
diff --git a/server/src/routes/ai.ts b/server/src/routes/ai.ts
index 8bbd109..b5dc6e6 100644
--- a/server/src/routes/ai.ts
+++ b/server/src/routes/ai.ts
@@ -5,7 +5,7 @@ import jwt from 'jsonwebtoken';
 const router = express.Router();
 const JWT_SECRET = process.env.JWT_SECRET || 'secret';
 const API_KEY = process.env.API_KEY;
-const MODEL_ID = 'gemini-1.5-flash';
+const MODEL_ID = 'gemini-2.0-flash';
 
 const authenticate = (req: any, res: any, next: any) => {
     const token = req.headers.authorization?.split(' ')[1];
@@ -35,11 +35,11 @@ router.post('/chat', async (req, res) => {
         const { systemInstruction, userMessage } = req.body;
 
         const model = ai.getGenerativeModel({
-            model: MODEL_ID,
-            systemInstruction
+            model: MODEL_ID
         });
 
-        const result = await model.generateContent(userMessage);
+        const prompt = `${systemInstruction}\n\nUser: ${userMessage}`;
+        const result = await model.generateContent(prompt);
         const response = result.response.text();
 
         res.json({ response });
diff --git a/services/geminiService.ts b/services/geminiService.ts
index 326708d..141998d 100644
--- a/services/geminiService.ts
+++ b/services/geminiService.ts
@@ -1,7 +1,7 @@
 import { WorkoutSession } from '../types';
 import { api } from './api';
 
-export const createFitnessChat = (history: WorkoutSession[]): any => {
+export const createFitnessChat = (history: WorkoutSession[], lang: 'en' | 'ru' = 'ru'): any => {
   // The original returned a Chat object.
   // Now we need to return something that behaves like it or refactor the UI.
   // The UI likely calls `chat.sendMessage(msg)`.
@@ -9,12 +9,12 @@ export const createFitnessChat = (history: WorkoutSession[]): any => {
 
   // Summarize data to reduce token count while keeping relevant context
   const summary = history.slice(0, 10).map(s => ({
-    date: new Date(s.startTime).toLocaleDateString('ru-RU'),
+    date: new Date(s.startTime).toLocaleDateString(lang === 'ru' ? 'ru-RU' : 'en-US'),
     userWeight: s.userBodyWeight,
-    exercises: s.sets.map(set => `${set.exerciseName}: ${set.weight ? set.weight + 'кг' : ''}${set.reps ? ' x ' + set.reps + 'повт' : ''} ${set.distanceMeters ? set.distanceMeters + 'м' : ''}`).join(', ')
+    exercises: s.sets.map(set => `${set.exerciseName}: ${set.weight ? set.weight + (lang === 'ru' ? 'кг' : 'kg') : ''}${set.reps ? ' x ' + set.reps + (lang === 'ru' ? 'повт' : 'reps') : ''} ${set.distanceMeters ? set.distanceMeters + (lang === 'ru' ? 'м' : 'm') : ''}`).join(', ')
   }));
 
-  const systemInstruction = `
+  const systemInstruction = lang === 'ru' ? `
     Ты — опытный и поддерживающий фитнес-тренер. 
     Твоя задача — анализировать тренировки пользователя и давать краткие, полезные советы на русском языке.
     
@@ -25,6 +25,18 @@ export const createFitnessChat = (history: WorkoutSession[]): any => {
 
     Если пользователь спрашивает о прогрессе, используй эти данные.
     Отвечай емко, мотивирующе. Избегай длинных лекций, если не просили.
+  ` : `
+    You are an experienced and supportive fitness coach.
+    Your task is to analyze the user's workouts and provide concise, helpful advice in English.
+    
+    Consider the user's weight (userWeight in json), if provided, when analyzing progress in bodyweight exercises.
+    
+    Here are the user's last 10 workouts (in JSON format):
+    ${JSON.stringify(summary)}
+
+    If the user asks about progress, use this data.
+    Answer concisely and motivationally. Avoid long lectures unless asked.
+    ALWAYS answer in the language the user speaks to you, defaulting to English if unsure.
   `;
 
   return {
@@ -34,6 +46,7 @@ export const createFitnessChat = (history: WorkoutSession[]): any => {
         userMessage
       });
       return {
+        text: res.response,
         response: {
           text: () => res.response
         }