init css file and bind with app

src/main/java/ch/zhaw/gartenverwaltung/bootstrap/AppLoader.java

@@ -73,7 +73,10 @@ public class AppLoader {
     public Object loadSceneToStage(String fxmlFile, Stage appendee) throws IOException {
         FXMLLoader loader = new FXMLLoader(Objects.requireNonNull(HelloApplication.class.getResource(fxmlFile)));
         Pane root = loader.load();
-        appendee.setScene(new Scene(root));
+        Scene scene = new Scene(root);
+        String css = Objects.requireNonNull(this.getClass().getResource("styles.css")).toExternalForm();
+        appendee.setScene(scene);
+        scene.getStylesheets().add(css);
         Object controller = loader.getController();
         annotationInject(controller);
         return controller;

src/main/resources/ch/zhaw/gartenverwaltung/TextFieldFormular.fxml

@@ -7,7 +7,8 @@
 <?import javafx.scene.layout.HBox?>
 
 
-<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="64.0" prefWidth="298.0" xmlns="http://javafx.com/javafx/1" xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.zhaw.gartenverwaltung.TextFieldFormularController">
+<AnchorPane maxHeight="-Infinity" maxWidth="-Infinity" minHeight="-Infinity" minWidth="-Infinity" prefHeight="64.0" prefWidth="298.0" xmlns="http://javafx.com/javafx/17"
+            xmlns:fx="http://javafx.com/fxml/1" fx:controller="ch.zhaw.gartenverwaltung.TextFieldFormularController">
    <children>
       <HBox alignment="CENTER" layoutX="153.0" layoutY="33.0" prefHeight="100.0" prefWidth="200.0" spacing="10.0" AnchorPane.bottomAnchor="0.0" AnchorPane.leftAnchor="0.0" AnchorPane.rightAnchor="0.0" AnchorPane.topAnchor="0.0">
          <children>

src/main/resources/ch/zhaw/gartenverwaltung/bootstrap/styles.css

@@ -0,0 +1,6 @@
+.button{
+    -fx-text-fill: rgb(49, 89, 23);
+    -fx-border-color: rgb(49, 89, 23);
+    -fx-border-radius: 5;
+    -fx-padding: 3 6 6 6;
+}