GUI: StartScreen

import javafx.application.Application;
import javafx.geometry.Insets;
import javafx.scene.Scene;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
import javafx.scene.layout.GridPane;
import javafx.scene.paint.Color;
import javafx.scene.text.Font;
import javafx.scene.text.FontWeight;
import javafx.stage.Stage;

import java.util.ArrayList;
import java.util.Collections;
import java.util.Scanner;

public class StartScreen extends Application {

    Stage window;
    GridPane grid;
    Scene startScene;
    Label numPlayers;
    Button onePlayer, twoPlayer;

    public static void main(String[] args) {

        launch(args);
    }

    @Override
    public void start(Stage primaryStage) throws Exception {
        Scanner input = new Scanner(System.in);

        window = primaryStage;
        window.setTitle("Trivia Game");

        grid = new GridPane();
        grid.setPadding(new Insets(10, 10, 10, 10));
        grid.setVgap(10);
        grid.setHgap(10);

        //Label numPlayers: 1 or 2 player
        numPlayers = new Label("Select the number of players: ");
        numPlayers.setFont(Font.font("Verdana", FontWeight.BOLD, 12));
        numPlayers.setTextFill(Color.WHITE);
        GridPane.setConstraints(numPlayers, 0, 0);

        //Button onePlayer & twoPlayer: creates buttons and assigns actions
        onePlayer = new Button("1 Player");
        final String IDLE_BUTTON_STYLE = "-fx-background-color: black;" +
                "-fx-text-fill: white;" +
                "-fx-border-style: solid inside;" +
                "-fx-border-width: 2;" +
                "-fx-border-insets: 0;" +
                "-fx-border-radius: 5;" +
                "-fx-border-color: #87CEFA;";
        final String HOVERED_BUTTON_STYLE = "-fx-background-color: black;" +
                "-fx-shadow-highlight-color: black;" +
                "-fx-text-fill: white;" +
                "-fx-border-style: solid inside;" +
                "-fx-border-width: 2;" +
                "-fx-border-insets: 0;" +
                "-fx-border-radius: 5;" +
                "-fx-border-color: #7CFC00";

        onePlayer.setStyle(IDLE_BUTTON_STYLE);
        onePlayer.setOnMouseEntered(e -> onePlayer.setStyle(HOVERED_BUTTON_STYLE));
        onePlayer.setOnMouseExited(e -> onePlayer.setStyle(IDLE_BUTTON_STYLE));

        onePlayer.setOnAction(e -> {
            window.hide();
            OnePlayerName.Display("Trivia Game: Names", "Enter name of player1: ");
        });
        twoPlayer = new Button("2 Player");

        twoPlayer.setStyle(IDLE_BUTTON_STYLE);
        twoPlayer.setOnMouseEntered(e -> twoPlayer.setStyle(HOVERED_BUTTON_STYLE));
        twoPlayer.setOnMouseExited(e -> twoPlayer.setStyle(IDLE_BUTTON_STYLE));

        twoPlayer.setOnAction(e -> {
            window.hide();
            TwoPlayerName.Display("Trivia Game: Names", "Enter name of player1: ", "Enter name of player2: ");
        });

        GridPane.setConstraints(onePlayer, 0, 1);
        GridPane.setConstraints(twoPlayer, 1, 1);
        grid.getChildren().addAll(numPlayers, onePlayer, twoPlayer);

        //Scene startScene: sets beginning scene
        grid.setStyle("-fx-background-color: linear-gradient(to bottom, black, #191970);");
        startScene = new Scene(grid, 300, 200);
        window.setScene(startScene);
        window.show();
    }

    public static ArrayList<Integer> QuestionOrder() {
        ArrayList<Integer> questions = new ArrayList<Integer>();
        //int number = (int) (Math.random() * 10);
        for (int i = 0; i < 10; i++) {
            questions.add(i);
        }

        Collections.shuffle(questions);

        int number;
        for (int i = 0; i < 10; i++) {
            number = questions.get(i);
        }
        return questions;
    }
}