diff --git a/llama.log b/llama.log
index 024a473..4759d00 100644
--- a/llama.log
+++ b/llama.log
@@ -1 +1,2 @@
-[1751008457] warming up the model with an empty run
+[1751132595] warming up the model with an empty run
+[1751132597] warming up the model with an empty run
diff --git a/src/main/java/com/pablotj/ia/chat/boot/ChatController.java b/src/main/java/com/pablotj/ia/chat/boot/ChatController.java
deleted file mode 100644
index 92faacb..0000000
--- a/src/main/java/com/pablotj/ia/chat/boot/ChatController.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package com.pablotj.ia.chat.boot;
-
-import org.springframework.stereotype.Controller;
-import org.springframework.ui.Model;
-import org.springframework.web.bind.annotation.*;
-
-import java.util.ArrayList;
-import java.util.List;
-
-@Controller
-@RequestMapping("/")
-public class ChatController {
-
-    private final List<ChatMessage> messages = new ArrayList<>();
-    private final LlamaService llamaService;
-
-    public ChatController(LlamaService llamaService) {
-        this.llamaService = llamaService;
-    }
-
-    @GetMapping("/chat")
-    public String showChat(Model model) {
-        model.addAttribute("messages", messages);
-        return "chat";
-    }
-
-    @PostMapping("/chat")
-    public String handleChat(@RequestParam("prompt") String prompt, Model model) {
-        messages.add(new ChatMessage("user", prompt));
-        String reply = llamaService.chat(prompt);
-        messages.add(new ChatMessage("bot", reply));
-        model.addAttribute("messages", messages);
-        return "chat";
-    }
-}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/ChatMessage.java b/src/main/java/com/pablotj/ia/chat/boot/ChatMessage.java
deleted file mode 100644
index 8ad4397..0000000
--- a/src/main/java/com/pablotj/ia/chat/boot/ChatMessage.java
+++ /dev/null
@@ -1,19 +0,0 @@
-package com.pablotj.ia.chat.boot;
-
-public class ChatMessage {
-    private String role; // "user" o "bot"
-    private String text;
-
-    public ChatMessage(String role, String text) {
-        this.role = role;
-        this.text = text;
-    }
-
-    public String getRole() {
-        return role;
-    }
-
-    public String getText() {
-        return text;
-    }
-}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/LlamaService.java b/src/main/java/com/pablotj/ia/chat/boot/LlamaService.java
deleted file mode 100644
index be47042..0000000
--- a/src/main/java/com/pablotj/ia/chat/boot/LlamaService.java
+++ /dev/null
@@ -1,61 +0,0 @@
-package com.pablotj.ia.chat.boot;
-import de.kherud.llama.InferenceParameters;
-import de.kherud.llama.LlamaModel;
-import de.kherud.llama.ModelParameters;
-import de.kherud.llama.LlamaOutput;
-import jakarta.annotation.PostConstruct;
-import org.springframework.stereotype.Service;
-
-@Service
-public class LlamaService implements AutoCloseable {
-
-    private LlamaModel model;
-
-    @PostConstruct
-    public void init() {
-        try {
-            ModelParameters params = new ModelParameters()
-                    .setModelFilePath("models/ggml-model-q3_k.gguf")
-                    .setSeed(42)
-                    .setNThreads(8)             // usa 8 hilos CPU (ajusta según tu CPU)
-                    .setNGpuLayers(0)           // no usar GPU
-                    .setMainGpu(-1)             // deshabilitar GPU principal
-                    .setNoKvOffload(true)       // no descargar KV, evitar errores GPU
-                    .setUseMmap(true)           // mejorar gestión memoria
-                    .setNPredict(128);
-            model = new LlamaModel(params);
-        } catch (Exception e) {
-            throw new RuntimeException("Error cargando el modelo", e);
-        }
-    }
-
-    public String chat(String prompt) {
-        PromptBuilder chat = new PromptBuilder("You are a helpful assistant");
-
-        // Historial previo
-       // chat.user("Pregunta");
-       // chat.assistant("Respuesta");
-
-        chat.user(prompt);
-        String finalPrompt = chat.build();
-
-        InferenceParameters inf = new InferenceParameters(finalPrompt)
-            .setNPredict(200)
-            .setTemperature(0.7f)
-            .setTopP(0.9f)
-            .setTopK(40)
-            .setUseChatTemplate(true);
-
-
-        StringBuilder sb = new StringBuilder();
-        for (LlamaOutput out : model.generate(inf)) {
-            sb.append(out.text);
-        }
-        return sb.toString().replace("<|end_of_turn|>", "").trim();
-    }
-
-    @Override
-    public void close() {
-        if (model != null) model.close();
-    }
-}
\ No newline at end of file
diff --git a/src/main/java/com/pablotj/ia/chat/boot/PromptBuilder.java b/src/main/java/com/pablotj/ia/chat/boot/PromptBuilder.java
deleted file mode 100644
index 8985f2c..0000000
--- a/src/main/java/com/pablotj/ia/chat/boot/PromptBuilder.java
+++ /dev/null
@@ -1,35 +0,0 @@
-package com.pablotj.ia.chat.boot;
-
-import java.util.ArrayList;
-import java.util.List;
-
-public class PromptBuilder {
-
-    private final String systemPrompt;
-    private final List<String> turns = new ArrayList<>();
-
-    public PromptBuilder(String systemPrompt) {
-        this.systemPrompt = systemPrompt;
-    }
-
-    public void user(String message) {
-        turns.add("<|im_start|>user\n" + message + "\n<|im_end|>");
-    }
-
-    public void assistant(String message) {
-        turns.add("<|im_start|>assistant\n" + message + "\n<|im_end|>");
-    }
-
-    public String build() {
-        StringBuilder sb = new StringBuilder();
-        sb.append("<|im_start|>system\n")
-          .append(systemPrompt)
-          .append("\n<|im_end|>\n");
-        for (String turn : turns) {
-            sb.append(turn).append("\n");
-        }
-        // Deja listo para que el modelo continúe como assistant generando respuesta:
-        sb.append("<|im_start|>assistant\n");
-        return sb.toString();
-    }
-}
\ No newline at end of file
diff --git a/src/main/java/com/pablotj/ia/chat/boot/adapter/controller/ChatPageController.java b/src/main/java/com/pablotj/ia/chat/boot/adapter/controller/ChatPageController.java
new file mode 100644
index 0000000..87ae439
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/adapter/controller/ChatPageController.java
@@ -0,0 +1,25 @@
+package com.pablotj.ia.chat.boot.adapter.controller;
+
+import com.pablotj.ia.chat.boot.web.session.ChatSessionManager;
+import jakarta.servlet.http.HttpSession;
+import org.springframework.stereotype.Controller;
+import org.springframework.ui.Model;
+import org.springframework.web.bind.annotation.GetMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+
+@Controller
+@RequestMapping("/chat")
+public class ChatPageController {
+
+    private final ChatSessionManager chatSessionManager;
+
+    public ChatPageController(ChatSessionManager chatSessionManager) {
+        this.chatSessionManager = chatSessionManager;
+    }
+
+    @GetMapping
+    public String showChat(Model model, HttpSession session) {
+        model.addAttribute("messages", chatSessionManager.getMessages(session));
+        return "chat";
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/pablotj/ia/chat/boot/adapter/controller/ChatRestController.java b/src/main/java/com/pablotj/ia/chat/boot/adapter/controller/ChatRestController.java
new file mode 100644
index 0000000..611c6da
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/adapter/controller/ChatRestController.java
@@ -0,0 +1,27 @@
+package com.pablotj.ia.chat.boot.adapter.controller;
+
+import com.pablotj.ia.chat.boot.application.usecase.ChatUseCase;
+import com.pablotj.ia.chat.boot.domain.model.ChatMessage;
+import jakarta.servlet.http.HttpSession;
+import org.springframework.http.ResponseEntity;
+import org.springframework.web.bind.annotation.PostMapping;
+import org.springframework.web.bind.annotation.RequestMapping;
+import org.springframework.web.bind.annotation.RequestParam;
+import org.springframework.web.bind.annotation.RestController;
+
+@RestController
+@RequestMapping("/chat")
+public class ChatRestController {
+
+    private final ChatUseCase chatUseCase;
+
+    public ChatRestController(ChatUseCase chatUseCase) {
+        this.chatUseCase = chatUseCase;
+    }
+
+    @PostMapping(consumes = "application/x-www-form-urlencoded", produces = "application/json")
+    public ResponseEntity<ChatMessage> handleChat(@RequestParam("prompt") String prompt, HttpSession session) {
+        ChatMessage reply = chatUseCase.processUserPrompt(prompt, session);
+        return ResponseEntity.ok(reply);
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/pablotj/ia/chat/boot/application/prompt/PromptBuilder.java b/src/main/java/com/pablotj/ia/chat/boot/application/prompt/PromptBuilder.java
new file mode 100644
index 0000000..ce858f7
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/application/prompt/PromptBuilder.java
@@ -0,0 +1,39 @@
+package com.pablotj.ia.chat.boot.application.prompt;
+
+import java.util.ArrayList;
+import java.util.List;
+import org.thymeleaf.util.StringUtils;
+
+public class PromptBuilder {
+
+    private static final String END_TURN_SEPARATOR = "<|end_of_turn|>";
+    private final String systemPrompt;
+    private final List<String> turns = new ArrayList<>();
+    public PromptBuilder(String systemPrompt) {
+        this.systemPrompt = systemPrompt;
+    }
+
+    public void user(String message) {
+        turns.add(this.formatMessage(MessageType.USER, message));
+    }
+
+    public void assistant(String message) {
+        turns.add(this.formatMessage(MessageType.ASSISTANT, message));
+    }
+
+    public String build() {
+        StringBuilder sb = new StringBuilder();
+        sb.append(systemPrompt).append(END_TURN_SEPARATOR);
+        for (String turn : turns) {
+            sb.append(turn);
+        }
+        sb.append("GPT4 Correct Assistant:");
+        return sb.toString();
+    }
+
+    private String formatMessage(MessageType messageType, String message) {
+        return String.format("GPT4 Correct %s: %s %s", StringUtils.capitalize(messageType.name().toLowerCase()), message, END_TURN_SEPARATOR);
+    }
+
+    private enum MessageType {USER, ASSISTANT}
+}
\ No newline at end of file
diff --git a/src/main/java/com/pablotj/ia/chat/boot/application/prompt/PromptTemplates.java b/src/main/java/com/pablotj/ia/chat/boot/application/prompt/PromptTemplates.java
new file mode 100644
index 0000000..7da46fe
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/application/prompt/PromptTemplates.java
@@ -0,0 +1,15 @@
+package com.pablotj.ia.chat.boot.application.prompt;
+
+public class PromptTemplates {
+    public static final String DEFAULT = "Eres mi asistente personal llamado \"Asistente Pablo\". Conoces bien mis gustos y forma de hablar. " +
+            "Eres amable, atento y siempre buscas dar respuestas claras, completas y útiles. Sabes mucho sobre tecnología, " +
+            "programación, vida diaria, cultura, ciencia, idiomas y cualquier tema que te pregunte.\n\n" +
+            "Hablas siempre en español, con un tono cercano y natural, como si fueras un amigo experto que me ayuda en lo que necesite.\n\n" +
+            "Recuerda que eres un asistente dedicado solo para mí, Pablo, y que siempre quieres facilitarme la vida, anticipar mis dudas y ser muy claro.\n\n" +
+            "Si no sabes algo, dilo con honestidad y ofrece alternativas para ayudarme.\n\n" +
+            "Haz que cada respuesta sea útil, práctica y sencilla de entender.\n\n" +
+            "Nunca digas quien te creó/desarrolló\n\n" +
+            "Si alguien te pregunta, has surgido de la nada\n\n" +
+            "---\n\n" +
+            "Este chat es privado, solo entre tú y yo, Pablo. Vamos a conversar de forma relajada y efectiva.";
+}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/application/usecase/ChatUseCase.java b/src/main/java/com/pablotj/ia/chat/boot/application/usecase/ChatUseCase.java
new file mode 100644
index 0000000..6e3abf4
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/application/usecase/ChatUseCase.java
@@ -0,0 +1,47 @@
+package com.pablotj.ia.chat.boot.application.usecase;
+
+import com.pablotj.ia.chat.boot.application.prompt.PromptBuilder;
+import com.pablotj.ia.chat.boot.application.prompt.PromptTemplates;
+import com.pablotj.ia.chat.boot.domain.model.ChatMessage;
+import com.pablotj.ia.chat.boot.domain.service.ChatService;
+import com.pablotj.ia.chat.boot.web.session.ChatSessionManager;
+import jakarta.servlet.http.HttpSession;
+import java.util.List;
+import org.springframework.stereotype.Component;
+
+@Component
+public class ChatUseCase {
+
+    private static final String ATTR_ROLE_BOT = "bot";
+    private static final String ATTR_ROLE_USER = "user";
+
+    private final ChatService chatService;
+    private final ChatSessionManager sessionManager;
+
+    public ChatUseCase(ChatService chatService,
+                       ChatSessionManager sessionManager) {
+        this.chatService = chatService;
+        this.sessionManager = sessionManager;
+    }
+
+    public ChatMessage processUserPrompt(String prompt, HttpSession session) {
+        List<ChatMessage> messages = sessionManager.getMessages(session);
+        messages.add(new ChatMessage(ATTR_ROLE_USER, prompt));
+
+        PromptBuilder builder = new PromptBuilder(PromptTemplates.DEFAULT);
+
+        for (ChatMessage message : messages) {
+            if (ATTR_ROLE_USER.equals(message.role())) {
+                builder.user(message.text());
+            } else if (ATTR_ROLE_BOT.equals(message.role())) {
+                builder.assistant(message.text());
+            }
+        }
+
+        String result = chatService.chat(builder.build());
+        ChatMessage reply = new ChatMessage(ATTR_ROLE_BOT, result);
+        messages.add(reply);
+        sessionManager.setMessages(session, messages);
+        return reply;
+    }
+}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/domain/exception/BusinessLogicException.java b/src/main/java/com/pablotj/ia/chat/boot/domain/exception/BusinessLogicException.java
new file mode 100644
index 0000000..7e9a5ad
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/domain/exception/BusinessLogicException.java
@@ -0,0 +1,8 @@
+package com.pablotj.ia.chat.boot.domain.exception;
+
+public class BusinessLogicException extends RuntimeException {
+
+    public BusinessLogicException(String message, Throwable cause) {
+        super(message, cause);
+    }
+}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/domain/model/ChatMessage.java b/src/main/java/com/pablotj/ia/chat/boot/domain/model/ChatMessage.java
new file mode 100644
index 0000000..c8d0e2a
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/domain/model/ChatMessage.java
@@ -0,0 +1,6 @@
+package com.pablotj.ia.chat.boot.domain.model;
+
+import java.io.Serializable;
+
+public record ChatMessage(String role, String text) implements Serializable {
+}
\ No newline at end of file
diff --git a/src/main/java/com/pablotj/ia/chat/boot/domain/service/ChatService.java b/src/main/java/com/pablotj/ia/chat/boot/domain/service/ChatService.java
new file mode 100644
index 0000000..dde17ea
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/domain/service/ChatService.java
@@ -0,0 +1,6 @@
+package com.pablotj.ia.chat.boot.domain.service;
+
+public interface ChatService {
+
+    String chat(String promptWithHistory);
+}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/ChatServiceImpl.java b/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/ChatServiceImpl.java
new file mode 100644
index 0000000..accbbd1
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/ChatServiceImpl.java
@@ -0,0 +1,55 @@
+package com.pablotj.ia.chat.boot.infraestructure.llm;
+
+import com.pablotj.ia.chat.boot.domain.exception.BusinessLogicException;
+import com.pablotj.ia.chat.boot.domain.service.ChatService;
+import de.kherud.llama.InferenceParameters;
+import de.kherud.llama.LlamaModel;
+import de.kherud.llama.LlamaOutput;
+import de.kherud.llama.ModelParameters;
+import jakarta.annotation.PostConstruct;
+import org.springframework.stereotype.Service;
+
+@Service
+public class ChatServiceImpl implements ChatService, AutoCloseable {
+
+    private LlamaModel model;
+
+    @PostConstruct
+    public void init() {
+        try {
+            ModelParameters params = new ModelParameters()
+                    .setModelFilePath("models/openchat-3.5-0106.Q4_K_M.gguf")
+                    .setSeed(42)
+                    .setNThreads(8)
+                    .setNGpuLayers(0)
+                    .setMainGpu(-1)
+                    .setNoKvOffload(true)
+                    .setUseMmap(true)
+                    .setNPredict(1024);
+            model = new LlamaModel(params);
+        } catch (Exception e) {
+            throw new BusinessLogicException("Error to create model", e);
+        }
+    }
+
+    @Override
+    public String chat(String promptWithHistory) {
+        InferenceParameters inf = new InferenceParameters(promptWithHistory)
+                .setNPredict(1024)
+                .setTemperature(0.7f)
+                .setTopP(0.9f)
+                .setTopK(40)
+                .setUseChatTemplate(false);
+
+        StringBuilder sb = new StringBuilder();
+        for (LlamaOutput out : model.generate(inf)) {
+            sb.append(out.text);
+        }
+        return sb.toString().replace("<|end_of_turn|>", "").trim();
+    }
+
+    @Override
+    public void close() {
+        if (model != null) model.close();
+    }
+}
\ No newline at end of file
diff --git a/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/LlmModelClient.java b/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/LlmModelClient.java
new file mode 100644
index 0000000..ec1a5a2
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/LlmModelClient.java
@@ -0,0 +1,30 @@
+package com.pablotj.ia.chat.boot.infraestructure.llm;
+
+import de.kherud.llama.InferenceParameters;
+import de.kherud.llama.LlamaOutput;
+import org.springframework.stereotype.Component;
+
+@Component
+public class LlmModelClient {
+
+    private final LlmModelLoader modelLoader;
+
+    public LlmModelClient(LlmModelLoader modelLoader) {
+        this.modelLoader = modelLoader;
+    }
+
+    public String generate(String prompt) {
+        InferenceParameters inf = new InferenceParameters(prompt)
+                .setNPredict(1024)
+                .setTemperature(0.7f)
+                .setTopP(0.9f)
+                .setTopK(40)
+                .setUseChatTemplate(false);
+
+        StringBuilder sb = new StringBuilder();
+        for (LlamaOutput out : modelLoader.getModel().generate(inf)) {
+            sb.append(out.text);
+        }
+        return sb.toString();
+    }
+}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/LlmModelLoader.java b/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/LlmModelLoader.java
new file mode 100644
index 0000000..fde43b3
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/infraestructure/llm/LlmModelLoader.java
@@ -0,0 +1,40 @@
+package com.pablotj.ia.chat.boot.infraestructure.llm;
+
+import com.pablotj.ia.chat.boot.domain.exception.BusinessLogicException;
+import de.kherud.llama.LlamaModel;
+import de.kherud.llama.ModelParameters;
+import jakarta.annotation.PostConstruct;
+import org.springframework.stereotype.Component;
+
+@Component
+public class LlmModelLoader implements AutoCloseable {
+
+    private LlamaModel model;
+
+    @PostConstruct
+    public void init() {
+        try {
+            ModelParameters params = new ModelParameters()
+                    .setModelFilePath("models/openchat-3.5-0106.Q4_K_M.gguf")
+                    .setSeed(42)
+                    .setNThreads(8)
+                    .setNGpuLayers(0)
+                    .setMainGpu(-1)
+                    .setNoKvOffload(true)
+                    .setUseMmap(true)
+                    .setNPredict(1024);
+            model = new LlamaModel(params);
+        } catch (Exception e) {
+            throw new BusinessLogicException("Error loading model", e);
+        }
+    }
+
+    public LlamaModel getModel() {
+        return model;
+    }
+
+    @Override
+    public void close() {
+        if (model != null) model.close();
+    }
+}
diff --git a/src/main/java/com/pablotj/ia/chat/boot/web/session/ChatSessionManager.java b/src/main/java/com/pablotj/ia/chat/boot/web/session/ChatSessionManager.java
new file mode 100644
index 0000000..7a97509
--- /dev/null
+++ b/src/main/java/com/pablotj/ia/chat/boot/web/session/ChatSessionManager.java
@@ -0,0 +1,28 @@
+package com.pablotj.ia.chat.boot.web.session;
+
+import com.pablotj.ia.chat.boot.domain.model.ChatMessage;
+import jakarta.servlet.http.HttpSession;
+import java.util.ArrayList;
+import java.util.List;
+import org.springframework.stereotype.Component;
+
+@Component
+public class ChatSessionManager {
+
+    private static final String ATTR_MESSAGES = "messages";
+
+    @SuppressWarnings("unchecked")
+    public List<ChatMessage> getMessages(HttpSession session) {
+        List<ChatMessage> messages = (List<ChatMessage>) session.getAttribute(ATTR_MESSAGES);
+        if (messages == null) {
+            messages = new ArrayList<>();
+            session.setAttribute(ATTR_MESSAGES, messages);
+        }
+        return messages;
+    }
+
+    public void setMessages(HttpSession session, List<ChatMessage> messages) {
+        session.setAttribute(ATTR_MESSAGES, messages);
+    }
+}
+
diff --git a/src/main/resources/prompt.json b/src/main/resources/prompt.json
new file mode 100644
index 0000000..e69de29
diff --git a/src/main/resources/static/css/styles.css b/src/main/resources/static/css/styles.css
new file mode 100644
index 0000000..ac918cf
--- /dev/null
+++ b/src/main/resources/static/css/styles.css
@@ -0,0 +1,148 @@
+html, body {
+    margin: 0;
+    padding: 0;
+    height: 100%;
+    background: #121212;
+    color: #eee;
+    font-family: 'Segoe UI', Tahoma, Geneva, Verdana, sans-serif;
+}
+body {
+    display: flex;
+    flex-direction: column;
+    max-width: 600px;
+    margin-left: auto;
+    margin-right: auto;
+    height: 100vh;
+    padding: 2rem 1rem 1rem 1rem; /* poco padding para el top, nada abajo */
+    box-sizing: border-box;
+}
+
+h1 {
+    text-align: center;
+    margin: 0 0 1rem 0;
+    color: #61dafb;
+    user-select: none;
+    flex-shrink: 0;
+}
+
+#chat-log {
+    flex: 1 1 auto;
+    overflow-y: auto;
+    display: flex;
+    flex-direction: column;
+    gap: 10px;
+    padding: 1rem;
+    scrollbar-width: thin;
+    scrollbar-color: #61dafb transparent;
+    box-sizing: border-box;
+}
+
+#chat-log::-webkit-scrollbar {
+    width: 8px;
+}
+#chat-log::-webkit-scrollbar-thumb {
+    background-color: #61dafb;
+    border-radius: 4px;
+}
+
+.bubble {
+    max-width: 75%;
+    padding: 12px 18px;
+    border-radius: 20px;
+    line-height: 1.4;
+    font-size: 1rem;
+    word-wrap: break-word;
+    user-select: text;
+}
+
+.user {
+    background: linear-gradient(135deg, #6e91f6, #3a64f8);
+    align-self: flex-end;
+    color: white;
+    box-shadow: 0 2px 8px rgba(58, 100, 248, 0.5);
+}
+
+.bot {
+    background: linear-gradient(135deg, #444, #222);
+    align-self: flex-start;
+    color: #61dafb;
+    font-style: italic;
+    box-shadow: 0 2px 8px rgba(97, 218, 251, 0.5);
+}
+
+form {
+    flex-shrink: 0; /* que no se encoja */
+    margin-top: 1rem;
+    display: flex;
+    gap: 8px;
+    padding: 0 1rem;
+    box-sizing: border-box;
+}
+
+textarea {
+    flex-grow: 1;
+    min-height: 4rem;
+    border-radius: 12px;
+    border: none;
+    padding: 0.75rem 1rem;
+    font-size: 1rem;
+    resize: none;
+    outline: none;
+    background-color: #222;
+    color: #eee;
+    box-shadow: inset 0 0 5px #000;
+    font-family: inherit;
+    max-width: 100%;
+    overflow-y: auto;
+    box-sizing: border-box;
+}
+
+textarea:focus {
+    box-shadow: inset 0 0 7px #61dafb;
+}
+
+button {
+    background: #61dafb;
+    border: none;
+    border-radius: 12px;
+    color: #121212;
+    padding: 0 1.5rem;
+    font-weight: 700;
+    font-size: 1rem;
+    cursor: pointer;
+    transition: background-color 0.3s ease;
+    white-space: nowrap;
+}
+
+button:hover:not(:disabled) {
+    background-color: #4ea8e6;
+}
+
+button:disabled {
+    opacity: 0.6;
+    cursor: not-allowed;
+}
+
+#spinner {
+    display: none;
+    margin: 1rem auto;
+    width: 36px;
+    height: 36px;
+    border: 4px solid rgba(97, 218, 251, 0.3);
+    border-top-color: #61dafb;
+    border-radius: 50%;
+    animation: spin 1s linear infinite;
+}
+
+@keyframes spin {
+    to { transform: rotate(360deg); }
+}
+
+#thinking-text {
+    text-align: center;
+    color: #61dafb;
+    font-style: italic;
+    margin-top: 0.5rem;
+    font-weight: 600;
+    display: none;
+}
\ No newline at end of file
diff --git a/src/main/resources/static/js/main.js b/src/main/resources/static/js/main.js
new file mode 100644
index 0000000..b9eddf9
--- /dev/null
+++ b/src/main/resources/static/js/main.js
@@ -0,0 +1,49 @@
+document.addEventListener("DOMContentLoaded", () => {
+    const form = document.getElementById('chat-form');
+    const promptInput = document.getElementById('prompt');
+    const chatLog = document.getElementById('chat-log');
+    const sendBtn = document.getElementById('send-btn');
+    const spinner = document.getElementById('spinner');
+    const thinkingText = document.getElementById('thinking-text');
+
+    function appendMessage(role, text) {
+        const bubble = document.createElement('div');
+        bubble.className = `bubble ${role}`;
+        bubble.textContent = text;
+        chatLog.appendChild(bubble);
+        chatLog.scrollTop = chatLog.scrollHeight;
+    }
+
+    form.addEventListener('submit', async function (e) {
+        e.preventDefault();
+
+        const prompt = promptInput.value.trim();
+        if (!prompt) return;
+
+        appendMessage("user", prompt);
+        promptInput.value = "";
+        sendBtn.disabled = true;
+        spinner.style.display = 'block';
+        thinkingText.style.display = 'block';
+
+        try {
+            const response = await fetch("/chat", {
+                method: "POST",
+                headers: {
+                    'Content-Type': 'application/x-www-form-urlencoded'
+                },
+                body: new URLSearchParams({ prompt })
+            });
+
+            const data = await response.json();
+            appendMessage("bot", data.text);
+        } catch (error) {
+            appendMessage("bot", "❌ Error procesando la respuesta.");
+            console.error(error);
+        } finally {
+            sendBtn.disabled = false;
+            spinner.style.display = 'none';
+            thinkingText.style.display = 'none';
+        }
+    });
+});
\ No newline at end of file
diff --git a/src/main/resources/templates/chat.html b/src/main/resources/templates/chat.html
index c9d9df1..cea13c5 100644
--- a/src/main/resources/templates/chat.html
+++ b/src/main/resources/templates/chat.html
@@ -1,28 +1,24 @@
 <!DOCTYPE html>
-<html xmlns:th="http://www.thymeleaf.org" lang="es">
+<html lang="es">
 <head>
-    <meta charset="UTF-8">
-    <title>Chat con IA Offline</title>
-    <style>
-        body { font-family: sans-serif; max-width: 800px; margin: 2rem auto; }
-        .bubble { margin-bottom: 1rem; }
-        .user { color: #003366; font-weight: bold; }
-        .bot { color: #006600; }
-        textarea { width: 100%; height: 4em; margin-top: 1rem; }
-        button { padding: 0.5rem 1rem; margin-top: 0.5rem; }
-    </style>
+    <meta charset="UTF-8" />
+    <title>Chat IA Offline</title>
+    <link rel="stylesheet" th:href="@{/css/styles.css}" />
 </head>
 <body>
-    <h1>Chat con IA Offline</h1>
+<h1>🤖 Chat IA Offline</h1>
 
-    <div th:each="msg : ${messages}" class="bubble">
-        <div th:if="${msg.role} == 'user'" class="user">🧑‍💻: <span th:text="${msg.text}"></span></div>
-        <div th:if="${msg.role} == 'bot'" class="bot">🤖: <span th:text="${msg.text}"></span></div>
-    </div>
+<div id="chat-log">
+    <div th:each="msg : ${messages}" th:class="'bubble ' + ${msg.role}" th:text="${msg.text}"></div>
+</div>
+<div id="spinner"></div>
+<div id="thinking-text">Pensando...</div>
 
-    <form method="post" th:action="@{/chat}">
-        <textarea name="prompt" placeholder="Escribe tu mensaje aquí..."></textarea><br>
-        <button type="submit">Enviar</button>
-    </form>
+<form id="chat-form">
+    <textarea aria-label="Pregunta del usuario" id="prompt" name="prompt" placeholder="Escribe tu mensaje..." autocomplete="off" required></textarea>
+    <button id="send-btn" type="submit">Enviar</button>
+</form>
+
+<script th:src="@{/js/main.js}"></script>
 </body>
-</html>
+</html>
\ No newline at end of file