Correct all thing say expect the one about switchRoot I didn't understand (Btw add some comment)

app/src/main/java/school_project/Controller.java

@@ -34,7 +34,7 @@ public class Controller extends Application {
         stage.setScene(new Scene(root));
     }
     public static void main(String[] args) {
-        launch(args);
+        launch();
     }
 }
 

app/src/main/java/school_project/Menu/MenuAcceuil.java

@@ -8,18 +8,16 @@ import javafx.scene.paint.Color;
 import javafx.scene.text.Font;
 import school_project.Controller;
 public class MenuAcceuil extends BorderPane {
-    private Button Play;
-    public static Button SelectLevel;
-    private Button Trophy;
-    private Label Title;
 
 
     public MenuAcceuil(){
         super();
-        Play = new Button("Play");
+        //create all the objet that i need
-        SelectLevel= new Button("Select Level");
+        Button Play = new Button("Play");
-        Trophy = new Button("Trophy");
+        Button SelectLevel= new Button("Select Level");
-        Title = new Label("Welcome to Road to Master");
+        Button Trophy = new Button("Trophy");
+        Label Title = new Label("Welcome to Road to Master");
+        //set up all the Button where i need
         setTop(Title);
         setLeft(Play);
         setRight(SelectLevel);
@@ -30,7 +28,6 @@ public class MenuAcceuil extends BorderPane {
         setAlignment(Play,Pos.CENTER);
         setAlignment(SelectLevel,Pos.CENTER);
         setAlignment(Trophy,Pos.CENTER);
-        //Menu.getStylesheets().add("style.css"); todo creat a file css
         setPadding(new Insets(20,60,20,60));
         SelectLevel.setOnAction(event ->  Controller.switchRoot(new MenuLevel(1)));
         getStyleClass().add("BorderPane");

app/src/main/java/school_project/Menu/MenuLevel.java

@@ -9,20 +9,26 @@ import javafx.scene.layout.RowConstraints;
 import school_project.Controller;
 
 public class MenuLevel extends GridPane {
-    public Button BckMenu;
+    private int StartLevel;
-    public Button[] Days = new Button[3];
-    public int StartLevel;
-    public ColumnConstraints[] Columns = new ColumnConstraints[3];
-    public RowConstraints[] Rows = new RowConstraints[5];
-
     public MenuLevel(int choose_day) {
-        BckMenu = new Button("Back to menu");
+
+        //create all Object that I need
+        RowConstraints[] Rows = new RowConstraints[5];
+        ColumnConstraints[] Columns = new ColumnConstraints[3];
+        Button[] Days = new Button[3];
+        Button BckMenu = new Button("Back to menu");
+
         BckMenu.setOnAction(event -> Controller.switchRoot(new MenuAcceuil()));
         setHalignment(BckMenu,HPos.CENTER);
         add(BckMenu,2,4);
+
+
         for (int i = 0; i < Days.length; i++){
             Days[i] = new Button("Day"+(i+1));
         }
+
+        //it's here that I know which day I can show on the screen
+
         if (choose_day == 1) {
             StartLevel = 1;
             add(Days[1],0,0);
@@ -30,6 +36,7 @@ public class MenuLevel extends GridPane {
             setHalignment(Days[1], HPos.CENTER);
             setHalignment(Days[2], HPos.CENTER);
         }
+
         else if (choose_day == 2) {
             StartLevel = 11;
             add(Days[0], 0, 0);
@@ -37,6 +44,7 @@ public class MenuLevel extends GridPane {
             setHalignment(Days[0], HPos.CENTER);
             setHalignment(Days[2], HPos.CENTER);
         }
+
         else if (choose_day == 3) {
             StartLevel = 21;
             add(Days[0], 0, 0);
@@ -44,10 +52,12 @@ public class MenuLevel extends GridPane {
             setHalignment(Days[0], HPos.CENTER);
             setHalignment(Days[1], HPos.CENTER);
         }
+
         Days[0].setOnAction(event -> Controller.switchRoot(new MenuLevel(1)));
         Days[1].setOnAction(event -> Controller.switchRoot(new MenuLevel(2)));
         Days[2].setOnAction(event -> Controller.switchRoot(new MenuLevel(3)));
 
+        //It's here that I put all buttons where I need (base on column not row)
         for (int i = 0; i < 3; i++) {
             for (int j = 1; j < 5; j++) {
                 if(i==0){
@@ -77,28 +87,24 @@ public class MenuLevel extends GridPane {
                 }
             }
         }
+
         for(int i=0;i<=2;i++){
             Columns[i] = new ColumnConstraints();
             Columns[i].setPercentWidth(33);
             getColumnConstraints().addAll(Columns[i]);
         }
+
         for (int i= 0;i<=4;i++){
             Rows[i] = new RowConstraints();
             Rows[i].setPercentHeight(20);
             getRowConstraints().addAll(Rows[i]);
         }
+
         setHgap(20);
         setVgap(20);
         setPadding(new Insets(20,10,10,20));
         getStyleClass().add("GridPane");
         getStylesheets().add(String.valueOf(getClass().getResource("StyleMenuAcceuil.css")));
-
-
-
-
-
-
-
     }
 }