diff --git a/CMakeLists.txt b/CMakeLists.txt
index ddc7d49..7fe178b 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -19,8 +19,12 @@ set(CXX_EXTENSIONS NO)
 set(BOOST_INCLUDE_LIBRARIES "pfr")
 option(CPM_USE_LOCAL_PACKAGES "Use local packages" ON)
 
-file(GLOB_RECURSE LIB_SOURCES "lib/src/*.cpp")
+file(GLOB_RECURSE LIB_SOURCES "src/lib/*.cpp")
 file(GLOB_RECURSE SOURCES "src/*.cpp")
+file(GLOB_RECURSE IMPL_SOURCES "src/*_impl.cpp")
+file(GLOB_RECURSE LIB_IMPL_SOURCES "src/lib/*_impl.cpp")
+list(REMOVE_ITEM LIB_SOURCES ${LIB_IMPL_SOURCES})
+list(REMOVE_ITEM SOURCES ${IMPL_SOURCES} ${LIB_SOURCES})
 set(CMAKE_CXX_MODULE_STD 1)
 
 set_target_properties(__cmake_cxx23 PROPERTIES CXX_EXTENSIONS OFF)
@@ -85,6 +89,8 @@ target_compile_features(larra_xmpp INTERFACE cxx_std_23)
 target_sources(larra_xmpp PUBLIC FILE_SET larraXMPPSet TYPE CXX_MODULES
   FILES ${LIB_SOURCES})
 
+target_sources(larra_xmpp PUBLIC ${LIB_IMPL_SOURCES})
+
 
 install(TARGETS larra_xmpp
   EXPORT larraXMPPTargets
@@ -115,6 +121,7 @@ target_link_libraries(larra larra_xmpp)
 target_sources(larra PUBLIC FILE_SET larraSet TYPE CXX_MODULES
   FILES ${SOURCES})
 
+target_sources(larra PUBLIC ${IMPL_SOURCES})
 
 install(TARGETS larra
     RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
diff --git a/src/application.cpp b/src/application.cpp
index 4d79a74..6a57c41 100644
--- a/src/application.cpp
+++ b/src/application.cpp
@@ -3,17 +3,16 @@ module;
 
 #include <print>
 export module larra.application;
-import larra.main_window;
 
 namespace larra {
 
 export struct Application : Gtk::Application {
   Application() : Gtk::Application("org.larra.larra") {
     Glib::set_application_name("Larra");
-  };
+  }
   static auto create() -> Glib::RefPtr<Application> {
     return Glib::make_refptr_for_instance<Application>(new Application{});  // NOLINT
-  };
+  }
   auto on_startup() -> void final {
     this->Gtk::Application::on_startup();
     this->add_action("preferences", sigc::mem_fun(*this, &Application::OnClickPreferences));
@@ -32,25 +31,15 @@ export struct Application : Gtk::Application {
     gmenu->append_submenu("Accounts", accountsMenu);
     gmenu->append_submenu("Help", helpMenu);
     this->set_menubar(gmenu);
-  };
+  }
 
-  auto on_activate() -> void final {
-    auto win = new MainWindow{};  // NOLINT
-    this->add_window(*win);
-    win->signal_hide().connect([win] {
-      delete win;  // NOLINT
-    });
-    win->set_show_menubar();
-    win->set_visible(true);
-  };
+  auto on_activate() -> void final;
 
   auto OnClickPreferences() -> void {
-
-  };
+  }
 
   auto OnClickManageAccounts() -> void {
-
-  };
+  }
 
   auto OnClickAbout() -> void {};
 };
diff --git a/src/application_impl.cpp b/src/application_impl.cpp
new file mode 100644
index 0000000..0d8cf16
--- /dev/null
+++ b/src/application_impl.cpp
@@ -0,0 +1,16 @@
+module larra.application;
+import larra.main_window;
+
+namespace larra {
+
+auto Application::on_activate() -> void {
+  auto win = new MainWindow{*this};  // NOLINT
+  this->add_window(*win);
+  win->signal_hide().connect([win] {
+    delete win;  // NOLINT
+  });
+  win->set_show_menubar();
+  win->set_visible(true);
+}
+
+}  // namespace larra
diff --git a/lib/src/library.cpp b/src/lib/library.cpp
similarity index 100%
rename from lib/src/library.cpp
rename to src/lib/library.cpp
diff --git a/src/main_window.cpp b/src/main_window.cpp
index b194dac..546b289 100644
--- a/src/main_window.cpp
+++ b/src/main_window.cpp
@@ -1,19 +1,21 @@
 module;
 #include <gtkmm.h>
 export module larra.main_window;
+import larra.application;
 
 namespace larra {
 
 export struct MainWindow : Gtk::ApplicationWindow {
   Gtk::Box main;
-
-  Gtk::Box leftPanel{Gtk::Orientation::VERTICAL};
-  Gtk::Box accounts{Gtk::Orientation::VERTICAL};
-
-  MainWindow() {
+  Application& app;
+  MainWindow(Application& app) : app(app) {
     this->set_title("Larra");
-    auto settings = Gtk::Settings::get_default();
-    this->main.append(this->leftPanel);
+    Gtk::Box leftPanel{Gtk::Orientation::VERTICAL};
+    leftPanel.set_halign(Gtk::Align::START);
+    leftPanel.set_expand(true);
+    Gtk::Box accounts{Gtk::Orientation::VERTICAL};
+    leftPanel.append(accounts);
+    this->main.append(leftPanel);
     this->set_child(this->main);
   }
 };