Не запускается JavaFX проект

Все работало, но потом я попробовал создать .jar, он не запускался. В попытках вернуть все к прежнему, я окончательно потерялся.

Выдает следующую ошибку:

/usr/lib/jvm/java-12-oracle/bin/java --add-modules javafx.base,javafx.graphics --add-reads javafx.base=ALL-UNNAMED --add-reads javafx.graphics=ALL-UNNAMED -Djava.library.path=/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib "-javaagent:/home/andriy/Java/IntelliJ IDEA/lib/idea_rt.jar=44303:/home/andriy/Java/IntelliJ IDEA/bin" -Dfile.encoding=UTF-8 -classpath /home/andriy/IdeaProjects/Calculator/out/production/Calculator:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/src.zip:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx-swt.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.web.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.base.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.fxml.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.media.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.swing.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.controls.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.graphics.jar -p /home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.base.jar:/home/andriy/Java/openjfx-11.0.2_linux-x64_bin-sdk/javafx-sdk-11.0.2/lib/javafx.graphics.jar sample.Main
(java:17017): Gtk-WARNING **: 19:03:47.568: Theme parsing error: gtk-widgets.css:238:26: Missing closing bracket for :not()
Exception in Application start method
java.lang.reflect.InvocationTargetException
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplicationWithArgs(LauncherImpl.java:464)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication(LauncherImpl.java:363)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
    at java.base/jdk.internal.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
    at java.base/jdk.internal.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
    at java.base/java.lang.reflect.Method.invoke(Method.java:567)
    at java.base/sun.launcher.LauncherHelper$FXHelper.main(LauncherHelper.java:1051)
Caused by: java.lang.RuntimeException: Exception in Application start method
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.launchApplication1(LauncherImpl.java:900)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication$2(LauncherImpl.java:195)
    at java.base/java.lang.Thread.run(Thread.java:835)
Caused by: java.lang.IllegalAccessError: class com.sun.javafx.fxml.FXMLLoaderHelper (in unnamed module @0x7398fc4) cannot access class com.sun.javafx.util.Utils (in module javafx.graphics) because module javafx.graphics does not export com.sun.javafx.util to unnamed module @0x7398fc4
    at com.sun.javafx.fxml.FXMLLoaderHelper.<clinit>(FXMLLoaderHelper.java:38)
    at javafx.fxml.FXMLLoader.<clinit>(FXMLLoader.java:2056)
    at sample.Main.start(Main.java:13)
    at javafx.graphics/com.sun.javafx.application.LauncherImpl.lambda$launchApplication1$9(LauncherImpl.java:846)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runAndWait$12(PlatformImpl.java:455)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$10(PlatformImpl.java:428)
    at java.base/java.security.AccessController.doPrivileged(AccessController.java:389)
    at javafx.graphics/com.sun.javafx.application.PlatformImpl.lambda$runLater$11(PlatformImpl.java:427)
    at javafx.graphics/com.sun.glass.ui.InvokeLaterDispatcher$Future.run(InvokeLaterDispatcher.java:96)
    at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication._runLoop(Native Method)
    at javafx.graphics/com.sun.glass.ui.gtk.GtkApplication.lambda$runLoop$11(GtkApplication.java:277)
    ... 1 more
Exception running application sample.Main
Process finished with exit code 1

Код програмы прилагается:

Main.java

package sample;
import javafx.application.Application;
import javafx.fxml.FXMLLoader;
import javafx.scene.Parent;
import javafx.scene.Scene;
import javafx.stage.Stage;
public class Main extends Application {
    @Override
    public void start(Stage primaryStage) throws Exception {
        Parent root = FXMLLoader.load(getClass().getResource("fxml/sample.fxml"));
        primaryStage.setTitle("Calculator");
        primaryStage.setScene(new Scene(root, 235, 300));
        primaryStage.setResizable(false);
        primaryStage.show();
    }

    public static void main(String[] args) {
        launch(args);
    }
}

Controller.java

package sample;
import javafx.fxml.FXML;
import javafx.scene.control.Button;
import javafx.scene.control.Label;
public class Controller {
    @FXML
    private Label labelField;
    @FXML
    private Button clr_btn;
    @FXML
    private Button plusminus_btn;
    @FXML
    private Button perc_btn;
    @FXML
    private Button plus_btn;
    @FXML
    private Button button_7;
    @FXML
    private Button button_8;
    @FXML
    private Button button_9;
    @FXML
    private Button mult_btn;
    @FXML
    private Button button_4;
    @FXML
    private Button button_5;
    @FXML
    private Button button_6;
    @FXML
    private Button minus_btn;
    @FXML
    private Button button_1;
    @FXML
    private Button button_2;
    @FXML
    private Button button_3;
    @FXML
    private Button comma_btn;
    @FXML
    private Button equal_btn;
    @FXML
    private Button div_btn;
    @FXML
    private Button button_0;
    private String str = "";
    private double firstNum = 0;
    private double secondNum = 0;
    private double result = 0;
    private char operation;
    @FXML
    void initialize(){
        comma_btn.setOnAction(event -> {
            if (!str.contains(".")) {
                if(str == "") {
                    str = str + "0.";
                }else{
                    str = str + ".";
                }
                labelField.setText(str);
            }
        });
        clr_btn.setOnAction(event -> {
            str = "";
            labelField.setText("0");
        });
        equal_btn.setOnAction(event -> {
            secondNum = Double.parseDouble(str);
            switch (operation){
                case '+':
                    result = firstNum + secondNum;
                    break;
                case '-':
                    result = firstNum - secondNum;
                    break;
                case '*':
                    result = firstNum * secondNum;
                    break;
                case '/':
                    if(secondNum != 0) {
                        result = firstNum / secondNum;
                    } else {
                        result = 0;
                    }
                    break;
            }
            labelField.setText(String.valueOf(result));
            str = String.valueOf(result);
        });
        plus_btn.setOnAction(event -> {
            operation = '+';
            firstNum = Double.parseDouble(str);
            str = "";
            labelField.setText("0");
        });
        minus_btn.setOnAction(event -> {
            operation = '-';
            firstNum = Double.parseDouble(str);
            str = "";
            labelField.setText("0");
        });
        mult_btn.setOnAction(event -> {
            operation = '*';
            firstNum = Double.parseDouble(str);
            str = "";
            labelField.setText("0");
        });
        div_btn.setOnAction(event -> {
            operation = '/';
            firstNum = Double.parseDouble(str);
            str = "";
            labelField.setText("0");
        });
        plusminus_btn.setOnAction(event -> {
            double temp = Double.parseDouble(str);
            temp = -1 * temp;
            str = String.valueOf(temp);
            labelField.setText(str);
        });
        perc_btn.setOnAction(event -> {
            if (firstNum != 0){
                secondNum = firstNum / 100 * Double.parseDouble(str);
                switch (operation){
                    case '+':
                        result = firstNum + secondNum;
                        break;
                    case '-':
                        result = firstNum - secondNum;
                        break;
                    case '*':
                        result = firstNum * secondNum;
                        break;
                    case '/':
                        result = firstNum / secondNum;
                        break;
                }
                labelField.setText(String.valueOf(result));
                str = String.valueOf(result);
            }
        });
        button_0.setOnAction(event -> {
            if(str != ""){
                str = str + '0';
                labelField.setText(str);
            }
        });
        button_1.setOnAction(event -> {
            str = str + '1';
            labelField.setText(str);
        });
        button_2.setOnAction(event -> {
            str = str + '2';
            labelField.setText(str);
        });
        button_3.setOnAction(event -> {
            str = str + '3';
            labelField.setText(str);
        });
        button_4.setOnAction(event -> {
            str = str + '4';
            labelField.setText(str);
        });
        button_5.setOnAction(event -> {
            str = str + '5';
            labelField.setText(str);
        });
        button_6.setOnAction(event -> {
            str = str + '6';
            labelField.setText(str);
        });
        button_7.setOnAction(event -> {
            str = str + '7';
            labelField.setText(str);
        });
        button_8.setOnAction(event -> {
            str = str + '8';
            labelField.setText(str);
        });
        button_9.setOnAction(event -> {
            str = str + '9';
            labelField.setText(str);
        });
    }
}

sample.fxml

<?xml version="1.0" encoding="UTF-8"?>
<?import javafx.geometry.Insets?>
<?import javafx.scene.Cursor?>
<?import javafx.scene.control.Button?>
<?import javafx.scene.control.Label?>
<?import javafx.scene.layout.AnchorPane?>
<?import javafx.scene.layout.ColumnConstraints?>
<?import javafx.scene.layout.GridPane?>
<?import javafx.scene.layout.RowConstraints?>
<?import javafx.scene.text.Font?>
<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="300.0" prefWidth="235.0" style="-fx-background-color: #363636;" xmlns="http://javafx.com/javafx/11.0.1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="sample.Controller">
    <children>
        <Label fx:id="labelField" alignment="CENTER_RIGHT" prefHeight="60.0" prefWidth="235.0" style="-fx-background-color: #363636; -fx-border-color: #363636; -fx-text-fill: #ffffff;" text="0" textAlignment="RIGHT" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
            <font>
                <Font name="System Bold" size="36.0" />
            </font>
        </Label>
        <GridPane layoutY="53.0" prefHeight="240.0" prefWidth="235.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="60.0">
            <columnConstraints>
                <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
                <ColumnConstraints hgrow="SOMETIMES" minWidth="10.0" prefWidth="100.0" />
            </columnConstraints>
            <rowConstraints>
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
                <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES" />
            </rowConstraints>
            <children>
                <Button fx:id="clr_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e0e0e0; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="AC">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <cursor>
                        <Cursor fx:constant="DEFAULT" />
                    </cursor>
                    <opaqueInsets>
                        <Insets />
                    </opaqueInsets>
                </Button>
                <Button fx:id="plusminus_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e0e0e0; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="+/-" GridPane.columnIndex="1">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="perc_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e0e0e0; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="\%" GridPane.columnIndex="2">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="div_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e3dc94; -fx-text-fill: #474747; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text=" ÷ " GridPane.columnIndex="3">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_7" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="7" GridPane.rowIndex="1">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_8" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="8" GridPane.columnIndex="1" GridPane.rowIndex="1">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_9" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="9" GridPane.columnIndex="2" GridPane.rowIndex="1">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="mult_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e3dc94; -fx-text-fill: #474747; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="×" GridPane.columnIndex="3" GridPane.rowIndex="1">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_4" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="4" GridPane.rowIndex="2">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_5" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="5" GridPane.columnIndex="1" GridPane.rowIndex="2">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_6" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="6" GridPane.columnIndex="2" GridPane.rowIndex="2">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="minus_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e3dc94; -fx-text-fill: #474747; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="-" GridPane.columnIndex="3" GridPane.rowIndex="2">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_1" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="1" GridPane.rowIndex="3">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_2" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="2" GridPane.columnIndex="1" GridPane.rowIndex="3">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_3" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="3" GridPane.columnIndex="2" GridPane.rowIndex="3">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="comma_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="," GridPane.columnIndex="2" GridPane.rowIndex="4">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="equal_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e3dc94; -fx-text-fill: #474747; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="=" GridPane.columnIndex="3" GridPane.rowIndex="4">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="plus_btn" alignment="CENTER" maxHeight="48.0" maxWidth="58.75" mnemonicParsing="false" prefHeight="48.0" prefWidth="58.75" style="-fx-background-color: #e3dc94; -fx-text-fill: #474747; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="+" GridPane.columnIndex="3" GridPane.rowIndex="3">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
                <Button fx:id="button_0" alignment="CENTER" maxHeight="48.0" maxWidth="119.5" mnemonicParsing="false" prefHeight="45.0" prefWidth="115.0" style="-fx-background-color: #999999; -fx-text-fill: #ffffff; -fx-border-color: #363636;" styleClass="btn" stylesheets="@../styles/style.css" text="0" GridPane.columnSpan="2" GridPane.rowIndex="4">
                    <font>
                        <Font name="System Bold" size="18.0" />
                    </font>
                    <opaqueInsets>
                        <Insets bottom="1.0" left="1.0" right="1.0" top="1.0" />
                    </opaqueInsets>
                </Button>
            </children>
        </GridPane>
    </children>
</AnchorPane>

style.css

.btn:pressed{
    -fx-background-color: #f5a742!important; }

Структура проекта: