diff --git a/cmake/Dependencies.cmake b/cmake/Dependencies.cmake
index faf5031..ef689cc 100644
--- a/cmake/Dependencies.cmake
+++ b/cmake/Dependencies.cmake
@@ -22,4 +22,4 @@ FetchContent_MakeAvailable(googletest)
 find_package(PkgConfig REQUIRED)
 
 # Check for gtkmm-4.0 specifically, not just gtk4
-pkg_check_modules(GTKMM REQUIRED gtkmm-4.0)
\ No newline at end of file
+pkg_check_modules(GTKMM REQUIRED gtkmm-4.0)
diff --git a/src/ap/CMakeLists.txt b/src/ap/CMakeLists.txt
index 7e9ae84..00c999a 100644
--- a/src/ap/CMakeLists.txt
+++ b/src/ap/CMakeLists.txt
@@ -18,4 +18,4 @@ target_sources(ap
 target_link_libraries(ap PRIVATE gtk4-settings)
 
 add_subdirectory(mvc)
-# add_subdirectory(mvvm)
\ No newline at end of file
+# add_subdirectory(mvvm)
diff --git a/src/ap/README.md b/src/ap/README.md
index 0eaf53b..030a31f 100644
--- a/src/ap/README.md
+++ b/src/ap/README.md
@@ -46,11 +46,11 @@ View → Controller → Model
 
 ### 4. Examples
 ### 4.1. simple_ap
-- Cos:
+- Pros:
     - Quick, Simple
-- Pos:
+- Cons:
     - Dependency: e.g. what happen when we delete  Gtk::Label m_labelMonitorA;
     - Scalability: 
     - Reusability:
 
-### 4.2. mvc_ap
\ No newline at end of file
+### 4.2. mvc_ap
diff --git a/src/ap/mvc/CMakeLists.txt b/src/ap/mvc/CMakeLists.txt
index 48ddf03..c265c19 100644
--- a/src/ap/mvc/CMakeLists.txt
+++ b/src/ap/mvc/CMakeLists.txt
@@ -9,4 +9,4 @@ target_sources(mvc_ap
     controller/Controller.cpp
 )
 
-target_link_libraries(mvc_ap PRIVATE gtk4-settings)
\ No newline at end of file
+target_link_libraries(mvc_ap PRIVATE gtk4-settings)
diff --git a/src/ap/mvc/IObserver.h b/src/ap/mvc/IObserver.h
index 60c9baf..2c4ed75 100644
--- a/src/ap/mvc/IObserver.h
+++ b/src/ap/mvc/IObserver.h
@@ -1,7 +1,8 @@
 #pragma once
+#include <string>
 
 class IObserver {
  public:
   virtual ~IObserver() = default;
   virtual void onDataChanged(const std::string& newData) = 0;
-};
\ No newline at end of file
+};
diff --git a/src/ap/mvc/controller/Controller.cpp b/src/ap/mvc/controller/Controller.cpp
index 843268a..b86d412 100644
--- a/src/ap/mvc/controller/Controller.cpp
+++ b/src/ap/mvc/controller/Controller.cpp
@@ -9,4 +9,4 @@ void Controller::updateRequest(const std::string& text) {
   // the Controller updates the Model when receiving new data from the View,
   // which then notifies all Views of the change
   model_->setData(text);
-}
\ No newline at end of file
+}
diff --git a/src/ap/mvc/controller/Controller.h b/src/ap/mvc/controller/Controller.h
index 37198f5..487b264 100644
--- a/src/ap/mvc/controller/Controller.h
+++ b/src/ap/mvc/controller/Controller.h
@@ -10,4 +10,4 @@ class Controller {
 
  private:
   std::shared_ptr<SharedData> model_;
-};
\ No newline at end of file
+};
diff --git a/src/ap/mvc/model/SharedData.cpp b/src/ap/mvc/model/SharedData.cpp
index 0f44a39..1f44c28 100644
--- a/src/ap/mvc/model/SharedData.cpp
+++ b/src/ap/mvc/model/SharedData.cpp
@@ -20,4 +20,4 @@ void SharedData::addObserver(IObserver* obs) {
 
 std::string SharedData::getData() const {
   return data_;
-}
\ No newline at end of file
+}
diff --git a/src/ap/mvc/model/SharedData.h b/src/ap/mvc/model/SharedData.h
index 83f3349..ddac039 100644
--- a/src/ap/mvc/model/SharedData.h
+++ b/src/ap/mvc/model/SharedData.h
@@ -18,4 +18,4 @@ class SharedData {
  private:
   std::string data_;
   std::vector<IObserver*> observers_;
-};
\ No newline at end of file
+};
diff --git a/src/ap/mvc/mvc_ap.cpp b/src/ap/mvc/mvc_ap.cpp
index e6cb20c..aa31661 100644
--- a/src/ap/mvc/mvc_ap.cpp
+++ b/src/ap/mvc/mvc_ap.cpp
@@ -71,4 +71,4 @@ ContainerWindow::ContainerWindow()
 int main(int argc, char* argv[]) {
   auto app = Gtk::Application::create("org.gtkmm.example.singlemvc");
   return app->make_window_and_run<ContainerWindow>(argc, argv);
-}
\ No newline at end of file
+}
diff --git a/src/ap/mvc/view/DisplayWidget.cpp b/src/ap/mvc/view/DisplayWidget.cpp
index 9686cbc..63599f2 100644
--- a/src/ap/mvc/view/DisplayWidget.cpp
+++ b/src/ap/mvc/view/DisplayWidget.cpp
@@ -3,8 +3,8 @@
 DisplayWidget::DisplayWidget(const std::string& title, const std::string& color,
                              const std::string& startData)
     : Gtk::Box(Gtk::Orientation::VERTICAL),
-      color_(color),
-      innerBox_(Gtk::Orientation::VERTICAL) {
+      innerBox_(Gtk::Orientation::VERTICAL),
+      color_(color) {
   frame_.set_label(title);
   frame_.set_margin(10);
 
@@ -18,12 +18,13 @@ DisplayWidget::DisplayWidget(const std::string& title, const std::string& color,
 }
 
 void DisplayWidget::updateLabel(const std::string& text) {
-  // Use HTML markup to change text color
+  // Escape text to prevent Pango markup injection
+  auto escaped = Glib::Markup::escape_text(text);
   std::string markup = "<span foreground='" + color_ +
-                       "' size='x-large' weight='bold'>" + text + "</span>";
+                       "' size='x-large' weight='bold'>" + escaped + "</span>";
   labelData_.set_markup(markup);
 }
 
 void DisplayWidget::onDataChanged(const std::string& newData) {
   updateLabel(newData);
-}
\ No newline at end of file
+}
diff --git a/src/ap/mvc/view/DisplayWidget.h b/src/ap/mvc/view/DisplayWidget.h
index a3e882f..e881d9f 100644
--- a/src/ap/mvc/view/DisplayWidget.h
+++ b/src/ap/mvc/view/DisplayWidget.h
@@ -1,6 +1,7 @@
+#pragma once
 #include <gtkmm.h>
 #include "../IObserver.h"
-#include "../controller/Controller.h"
+
 class DisplayWidget : public Gtk::Box, public IObserver {
  public:
   DisplayWidget(const std::string& title, const std::string& color,
@@ -14,4 +15,4 @@ class DisplayWidget : public Gtk::Box, public IObserver {
   Gtk::Box innerBox_;
   Gtk::Label labelData_;
   std::string color_;
-};
\ No newline at end of file
+};
diff --git a/src/ap/mvc/view/EditorWidget.cpp b/src/ap/mvc/view/EditorWidget.cpp
index aea6e51..d9affda 100644
--- a/src/ap/mvc/view/EditorWidget.cpp
+++ b/src/ap/mvc/view/EditorWidget.cpp
@@ -1,10 +1,10 @@
 #include "EditorWidget.h"
-#include <iostream>
+
 EditorWidget::EditorWidget(std::shared_ptr<Controller> c,
                            const std::string& initData)
     : Gtk::Box(Gtk::Orientation::VERTICAL),
-      controller_(c),
-      innerBox_(Gtk::Orientation::VERTICAL) {
+      innerBox_(Gtk::Orientation::VERTICAL),
+      controller_(c) {
   // Create a beautiful border
   frame_.set_label("ZONE 1: EDITOR (Input View)");
   frame_.set_margin(10);
@@ -22,18 +22,14 @@ EditorWidget::EditorWidget(std::shared_ptr<Controller> c,
 
   frame_.set_child(innerBox_);
   this->append(frame_);  // Add a frame to the main Box of this class
-  controller_ = c;
+
   // MVC logic to help the Controller receive update input from the View
-  button_.signal_clicked().connect([this]() {
-    std::cout << "1\n";
-    controller_->updateRequest(entry_.get_text());
-    std::cout << "2\n";
-  });
+  button_.signal_clicked().connect(
+      [this]() { controller_->updateRequest(entry_.get_text()); });
 }
 
 void EditorWidget::onDataChanged(const std::string& newData) {
-  // Fix string comparison error or do not thing ?
   if (entry_.get_text() != Glib::ustring(newData)) {
     entry_.set_text(newData);
   }
-}
\ No newline at end of file
+}
diff --git a/src/ap/mvc/view/EditorWidget.h b/src/ap/mvc/view/EditorWidget.h
index 88c69b9..1f46393 100644
--- a/src/ap/mvc/view/EditorWidget.h
+++ b/src/ap/mvc/view/EditorWidget.h
@@ -17,4 +17,4 @@ class EditorWidget : public Gtk::Box, public IObserver {
   Gtk::Button button_;
 
   std::shared_ptr<Controller> controller_;
-};
\ No newline at end of file
+};
diff --git a/src/ap/simple_ap.cpp b/src/ap/simple_ap.cpp
index 9d297cd..110c043 100644
--- a/src/ap/simple_ap.cpp
+++ b/src/ap/simple_ap.cpp
@@ -87,13 +87,16 @@ class MainWindow : public Gtk::Window {
       if (text.empty())
         return;
 
+      // Escape text to prevent Pango markup injection
+      auto escaped = Glib::Markup::escape_text(text);
+
       // Step 2: Update Monitor A (Hard-coded) directly
       m_labelMonitorA.set_markup("<span foreground='blue' size='x-large'>" +
-                                 text + "</span>");
+                                 escaped + "</span>");
 
       // Step 3: Update Monitor B (Hard-coded) directly
       m_labelMonitorB.set_markup("<span foreground='red' size='x-large'>" +
-                                 text + "</span>");
+                                 escaped + "</span>");
       std::cout << "Updated directly without Model!" << std::endl;
     });
   }
@@ -102,4 +105,4 @@ class MainWindow : public Gtk::Window {
 int main(int argc, char* argv[]) {
   auto app = Gtk::Application::create("org.gtkmm.example.nomvc");
   return app->make_window_and_run<MainWindow>(argc, argv);
-}
\ No newline at end of file
+}