all requierd methods implemented

src/main/java/workshop/Controller.java

@@ -1,6 +1,7 @@
 package workshop;
 
 import javafx.fxml.FXML;
+import javafx.scene.control.Alert;
 import javafx.scene.control.Label;
 import javafx.scene.control.Button;
 
@@ -17,25 +18,43 @@ public class Controller {
     @FXML
     private void buyBasic() {
         // TODO: Call showAlert() with a message indicating the user entered the payment gateway
+        showAlert("Basic Plan Selected.");
     }
 
     @FXML
     private void buyPro() {
         // TODO: Call showAlert() with a message indicating the user entered the payment gateway
+        showAlert("Pro Plan Selected.");
     }
 
     @FXML
     private void buyEnterprise() {
         // TODO: Call showAlert() with a message indicating the user entered the payment gateway
+        showAlert("Enterprise Plan Selected.");
     }
 
     @FXML
     private void toggleTheme() {
         // TODO: Toggle the isDark flag. If dark, switch to style.css and set button text to "Switch to Light Mode"
+
+        isDark = !isDark;
+
+        themeToggle.getScene().getStylesheets().clear();
+        if (isDark) {
+            themeToggle.getScene().getStylesheets().add(getClass().getResource("light.css").toExternalForm());
+            themeToggle.setText("Switch to Dark Mode");
+        }
         // TODO: If light, switch to light.css and set button text to "Switch to Dark Mode"
+        else {
+            themeToggle.getScene().getStylesheets().add(getClass().getResource("style.css").toExternalForm());
+            themeToggle.setText("Switch to Light Mode");
+        }
     }
 
     private void showAlert(String message) {
         // TODO: Create a new Alert of type INFORMATION with the given message and display it
+        Alert alert = new Alert(Alert.AlertType.INFORMATION);
+        alert.setHeaderText(message);
+        alert.show();
     }
 }