diff --git a/src/main/java/de/hitec/nhplus/Main.java b/src/main/java/de/hitec/nhplus/Main.java
index 9a7eac5..54ef1bc 100644
--- a/src/main/java/de/hitec/nhplus/Main.java
+++ b/src/main/java/de/hitec/nhplus/Main.java
@@ -6,6 +6,7 @@ import javafx.application.Application;
 import javafx.application.Platform;
 import javafx.fxml.FXMLLoader;
 import javafx.scene.Scene;
+import javafx.scene.control.TabPane;
 import javafx.scene.layout.BorderPane;
 import javafx.stage.Stage;
 
@@ -23,12 +24,12 @@ public class Main extends Application {
     public void mainWindow() {
         try {
             FXMLLoader loader = new FXMLLoader(Main.class.getResource("/de/hitec/nhplus/MainWindowView.fxml"));
-            BorderPane pane = loader.load();
+            TabPane pane = loader.load();
 
             Scene scene = new Scene(pane);
             this.primaryStage.setTitle("NHPlus");
             this.primaryStage.setScene(scene);
-            this.primaryStage.setResizable(false);
+            this.primaryStage.setResizable(true);
             this.primaryStage.show();
 
             this.primaryStage.setOnCloseRequest(event -> {
diff --git a/src/main/java/de/hitec/nhplus/main/MainWindowController.java b/src/main/java/de/hitec/nhplus/main/MainWindowController.java
index 078bcb2..21b8da1 100644
--- a/src/main/java/de/hitec/nhplus/main/MainWindowController.java
+++ b/src/main/java/de/hitec/nhplus/main/MainWindowController.java
@@ -1,37 +1,58 @@
 package de.hitec.nhplus.main;
 
 import de.hitec.nhplus.Main;
-import javafx.event.ActionEvent;
 import javafx.fxml.FXML;
 import javafx.fxml.FXMLLoader;
+import javafx.scene.control.Tab;
+import javafx.scene.layout.AnchorPane;
 import javafx.scene.layout.BorderPane;
 
 import java.io.IOException;
 
 public class MainWindowController {
-
     @FXML
-    private BorderPane mainBorderPane;
+    private AnchorPane patientPage;
+    @FXML
+    private Tab patientTab;
+    @FXML
+    private AnchorPane treatmentPage;
+    @FXML
+    private Tab treatmentTab;
+
     @FXML
     public void initialize() {
-        handleShowAllPatient(null);
+        loadPatientPage();
+        loadTreatmentsPage();
+
+        patientTab.setOnSelectionChanged(event -> loadPatientPage());
+        treatmentTab.setOnSelectionChanged(event -> loadTreatmentsPage());
     }
 
-    @FXML
-    private void handleShowAllPatient(ActionEvent event) {
-        FXMLLoader loader = new FXMLLoader(Main.class.getResource("/de/hitec/nhplus/patient/AllPatientView.fxml"));
+    private void loadPatientPage() {
         try {
-            mainBorderPane.setCenter(loader.load());
+            BorderPane patientsPane = FXMLLoader.load(
+                    Main.class.getResource("/de/hitec/nhplus/patient/AllPatientView.fxml")
+            );
+            patientPage.getChildren().setAll(patientsPane);
+            AnchorPane.setTopAnchor(patientsPane, 0d);
+            AnchorPane.setBottomAnchor(patientsPane, 0d);
+            AnchorPane.setLeftAnchor(patientsPane, 0d);
+            AnchorPane.setRightAnchor(patientsPane, 0d);
         } catch (IOException exception) {
             exception.printStackTrace();
         }
     }
 
-    @FXML
-    private void handleShowAllTreatments(ActionEvent event) {
-        FXMLLoader loader = new FXMLLoader(Main.class.getResource("/de/hitec/nhplus/treatment/AllTreatmentView.fxml"));
+    private void loadTreatmentsPage() {
         try {
-            mainBorderPane.setCenter(loader.load());
+            BorderPane treatmentsPane = FXMLLoader.load(
+                    Main.class.getResource("/de/hitec/nhplus/treatment/AllTreatmentView.fxml")
+            );
+            treatmentPage.getChildren().setAll(treatmentsPane);
+            AnchorPane.setTopAnchor(treatmentsPane, 0d);
+            AnchorPane.setBottomAnchor(treatmentsPane, 0d);
+            AnchorPane.setLeftAnchor(treatmentsPane, 0d);
+            AnchorPane.setRightAnchor(treatmentsPane, 0d);
         } catch (IOException exception) {
             exception.printStackTrace();
         }
diff --git a/src/main/resources/de/hitec/nhplus/Application.css b/src/main/resources/de/hitec/nhplus/Application.css
index feaa0ee..b7e3076 100644
--- a/src/main/resources/de/hitec/nhplus/Application.css
+++ b/src/main/resources/de/hitec/nhplus/Application.css
@@ -1,6 +1 @@
 /* https://materialui.co/colors */
-.tabs{
-    -fx-background-color: #1565C0;
-    -fx-padding: 4px;
-    -fx-spacing: 4px;
-}
diff --git a/src/main/resources/de/hitec/nhplus/MainWindowView.fxml b/src/main/resources/de/hitec/nhplus/MainWindowView.fxml
index 861efcc..00eab26 100644
--- a/src/main/resources/de/hitec/nhplus/MainWindowView.fxml
+++ b/src/main/resources/de/hitec/nhplus/MainWindowView.fxml
@@ -1,44 +1,18 @@
 <?xml version="1.0" encoding="UTF-8"?>
 
-<?import javafx.geometry.Insets?>
-<?import javafx.scene.control.Button?>
-<?import javafx.scene.layout.BorderPane?>
-<?import javafx.scene.layout.HBox?>
-<BorderPane
-        fx:id="mainBorderPane"
-        maxHeight="-Infinity"
-        maxWidth="-Infinity"
-        minHeight="-Infinity"
-        minWidth="-Infinity"
-        prefHeight="688.0"
-        prefWidth="926.0"
-        xmlns="http://javafx.com/javafx/10.0.2-internal"
+<?import javafx.scene.control.Tab?>
+<?import javafx.scene.control.TabPane?>
+<?import javafx.scene.layout.AnchorPane?>
+<TabPane
+        tabClosingPolicy="UNAVAILABLE"
+        xmlns="http://javafx.com/javafx/17.0.2-ea"
         xmlns:fx="http://javafx.com/fxml/1"
-        fx:controller="de.hitec.nhplus.main.MainWindowController">
-    <top>
-        <HBox id="tabs" alignment="CENTER_LEFT" styleClass="tabs" stylesheets="@Application.css">
-            <children>
-                <Button
-                        alignment="CENTER"
-                        contentDisplay="CENTER"
-                        mnemonicParsing="false"
-                        onAction="#handleShowAllPatient"
-                        prefWidth="105.0"
-                        text="Patienten"
-                >
-                    <opaqueInsets>
-                        <Insets/>
-                    </opaqueInsets>
-                </Button>
-                <Button
-                        alignment="CENTER"
-                        contentDisplay="CENTER"
-                        mnemonicParsing="false"
-                        onAction="#handleShowAllTreatments"
-                        prefWidth="105.0"
-                        text="Behandlungen"
-                ></Button>
-            </children>
-        </HBox>
-    </top>
-</BorderPane>
+        fx:controller="de.hitec.nhplus.main.MainWindowController"
+>
+    <Tab fx:id="patientTab" text="Patienten">
+        <AnchorPane fx:id="patientPage"/>
+    </Tab>
+    <Tab fx:id="treatmentTab" text="Behandlungen">
+        <AnchorPane fx:id="treatmentPage"/>
+    </Tab>
+</TabPane>
diff --git a/src/main/resources/de/hitec/nhplus/patient/AllPatientView.fxml b/src/main/resources/de/hitec/nhplus/patient/AllPatientView.fxml
index a7908fa..e1a2e5a 100644
--- a/src/main/resources/de/hitec/nhplus/patient/AllPatientView.fxml
+++ b/src/main/resources/de/hitec/nhplus/patient/AllPatientView.fxml
@@ -3,44 +3,72 @@
 <?import javafx.geometry.Insets?>
 <?import javafx.scene.control.*?>
 <?import javafx.scene.layout.*?>
-<?import javafx.scene.text.Font?>
-<AnchorPane
-        prefHeight="500.0"
-        prefWidth="855.0"
+<BorderPane
         xmlns="http://javafx.com/javafx/11.0.1"
         xmlns:fx="http://javafx.com/fxml/1"
-        fx:controller="de.hitec.nhplus.patient.AllPatientController">
-    <children>
+        fx:controller="de.hitec.nhplus.patient.AllPatientController"
+>
+    <padding>
+        <Insets top="8" left="8" bottom="8" right="8"/>
+    </padding>
+    <center>
         <TableView
                 fx:id="tableView"
-                editable="true" layoutX="31.0"
-                layoutY="120.0" prefHeight="287.0"
-                prefWidth="825.0"
-                AnchorPane.bottomAnchor="100.0"
-                AnchorPane.leftAnchor="15.0"
-                AnchorPane.rightAnchor="15.0"
-                AnchorPane.topAnchor="80.0">
+                editable="true"
+        >
             <columns>
-                <TableColumn fx:id="columnId" maxWidth="-1.0" minWidth="40.0" prefWidth="5.0" text="ID"/>
-                <TableColumn fx:id="columnSurname" maxWidth="-1.0" minWidth="140.0" onEditCommit="#handleOnEditSurname"
-                             prefWidth="100.0" text="Nachname"/>
-                <TableColumn fx:id="columnFirstName" maxWidth="-1.00" minWidth="140.0"
-                             onEditCommit="#handleOnEditFirstname" prefWidth="75.0" text="Vorname"/>
-                <TableColumn fx:id="columnDateOfBirth" maxWidth="-1.0" minWidth="140.0"
-                             onEditCommit="#handleOnEditDateOfBirth" prefWidth="75.0" text="Geburtstag"/>
-                <TableColumn fx:id="columnCareLevel" maxWidth="-1.0" minWidth="140.0"
-                             onEditCommit="#handleOnEditCareLevel" prefWidth="75.0" text="Pflegegrad"/>
-                <TableColumn fx:id="columnRoomNumber" maxWidth="-1.0" minWidth="140.0"
-                             onEditCommit="#handleOnEditRoomNumber" prefWidth="75.0" text="Raum"/>
+                <TableColumn
+                        fx:id="columnId"
+                        minWidth="40.0"
+                        text="ID"
+                />
+                <TableColumn
+                        fx:id="columnSurname"
+                        minWidth="140.0"
+                        onEditCommit="#handleOnEditSurname"
+                        text="Nachname"
+                />
+                <TableColumn
+                        fx:id="columnFirstName"
+                        minWidth="140.0"
+                        onEditCommit="#handleOnEditFirstname"
+                        text="Vorname"
+                />
+                <TableColumn
+                        fx:id="columnDateOfBirth"
+                        minWidth="140.0"
+                        onEditCommit="#handleOnEditDateOfBirth"
+                        text="Geburtstag"
+                />
+                <TableColumn
+                        fx:id="columnCareLevel"
+                        minWidth="140.0"
+                        onEditCommit="#handleOnEditCareLevel"
+                        prefWidth="75.0"
+                        text="Pflegegrad"
+                />
+                <TableColumn
+                        fx:id="columnRoomNumber"
+                        minWidth="140.0"
+                        onEditCommit="#handleOnEditRoomNumber"
+                        text="Raum"
+                />
             </columns>
             <columnResizePolicy>
                 <TableView fx:constant="CONSTRAINED_RESIZE_POLICY"/>
             </columnResizePolicy>
         </TableView>
-        <HBox layoutX="623.0" layoutY="419.3999938964844" spacing="10.0" AnchorPane.bottomAnchor="15.0"
-              AnchorPane.leftAnchor="15.0" AnchorPane.rightAnchor="15.0">
-            <children>
-                <GridPane hgap="10.0" vgap="10.0">
+    </center>
+    <bottom>
+        <BorderPane>
+            <BorderPane.margin>
+                <Insets top="8.0"/>
+            </BorderPane.margin>
+            <center>
+                <GridPane hgap="8.0" vgap="8.0">
+                    <padding>
+                        <Insets right="48.0"/>
+                    </padding>
                     <columnConstraints>
                         <ColumnConstraints halignment="LEFT" hgrow="SOMETIMES" prefWidth="200.0"/>
                         <ColumnConstraints halignment="LEFT" hgrow="SOMETIMES" minWidth="200.0" prefWidth="200.0"/>
@@ -50,48 +78,65 @@
                         <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES"/>
                         <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES"/>
                     </rowConstraints>
-                    <children>
-                        <TextField fx:id="textFieldFirstName" minWidth="200.0" prefHeight="26.0" prefWidth="200.0"
-                                   promptText="Vorname"/>
-                        <TextField fx:id="textFieldSurname" minWidth="200.0" prefHeight="26.0" prefWidth="200.0"
-                                   promptText="Nachname" GridPane.columnIndex="1"/>
-                        <TextField fx:id="textFieldDateOfBirth" minWidth="160.0" prefWidth="160.0"
-                                   promptText="Geburtstag" GridPane.columnIndex="2"/>
-                        <TextField fx:id="textFieldCareLevel" prefHeight="26.0" prefWidth="200.0"
-                                   promptText="Pflegegrad" GridPane.rowIndex="1"/>
-                        <TextField fx:id="textFieldRoomNumber" prefHeight="26.0" prefWidth="200.0" promptText="Raum"
-                                   GridPane.columnIndex="1" GridPane.rowIndex="1"/>
-                    </children>
-                    <padding>
-                        <Insets right="10.0"/>
-                    </padding>
-                    <HBox.margin>
-                        <Insets/>
-                    </HBox.margin>
+                    <TextField
+                            fx:id="textFieldFirstName"
+                            minWidth="200.0"
+                            prefHeight="26.0"
+                            prefWidth="200.0"
+                            promptText="Vorname"
+                    />
+                    <TextField
+                            fx:id="textFieldSurname"
+                            minWidth="200.0"
+                            prefHeight="26.0"
+                            prefWidth="200.0"
+                            promptText="Nachname"
+                            GridPane.columnIndex="1"
+                    />
+                    <TextField
+                            fx:id="textFieldDateOfBirth"
+                            minWidth="160.0"
+                            prefWidth="160.0"
+
+                            promptText="Geburtstag"
+                            GridPane.columnIndex="2"
+                    />
+                    <TextField
+                            fx:id="textFieldCareLevel"
+                            prefHeight="26.0"
+                            prefWidth="200.0"
+
+                            promptText="Pflegegrad"
+                            GridPane.rowIndex="1"
+                    />
+                    <TextField
+                            fx:id="textFieldRoomNumber"
+                            prefHeight="26.0"
+                            prefWidth="200.0"
+                            promptText="Raum"
+                            GridPane.columnIndex="1"
+                            GridPane.rowIndex="1"
+                    />
                 </GridPane>
-                <HBox alignment="TOP_CENTER" prefWidth="190.0" spacing="10.0">
-                    <children>
-                        <Button fx:id="buttonAdd" mnemonicParsing="false" onAction="#handleAdd" prefWidth="90.0"
-                                text="Hinzufügen"/>
-                        <Button fx:id="buttonDelete" mnemonicParsing="false" onAction="#handleDelete" prefWidth="90.0"
-                                text="Löschen"/>
-                    </children>
-                </HBox>
-            </children>
-        </HBox>
-        <HBox alignment="TOP_CENTER" layoutX="10.0" layoutY="10.0" prefWidth="200.0" spacing="25.0"
-              AnchorPane.leftAnchor="15.0" AnchorPane.rightAnchor="15.0" AnchorPane.topAnchor="5.0">
-            <children>
-                <Label alignment="CENTER" contentDisplay="CENTER" minWidth="400.0" text="Patienten"
-                       textAlignment="CENTER">
-                    <font>
-                        <Font size="36.0"/>
-                    </font>
-                </Label>
-            </children>
-        </HBox>
-    </children>
-    <padding>
-        <Insets top="10.0"/>
-    </padding>
-</AnchorPane>
+            </center>
+            <right>
+                <VBox spacing="8.0">
+                    <Button
+                            fx:id="buttonAdd"
+                            mnemonicParsing="false"
+                            onAction="#handleAdd"
+                            prefWidth="90.0"
+                            text="Hinzufügen"
+                    />
+                    <Button
+                            fx:id="buttonDelete"
+                            mnemonicParsing="false"
+                            onAction="#handleDelete"
+                            prefWidth="90.0"
+                            text="Löschen"
+                    />
+                </VBox>
+            </right>
+        </BorderPane>
+    </bottom>
+</BorderPane>
diff --git a/src/main/resources/de/hitec/nhplus/treatment/AllTreatmentView.fxml b/src/main/resources/de/hitec/nhplus/treatment/AllTreatmentView.fxml
index 056004a..ec89105 100644
--- a/src/main/resources/de/hitec/nhplus/treatment/AllTreatmentView.fxml
+++ b/src/main/resources/de/hitec/nhplus/treatment/AllTreatmentView.fxml
@@ -3,70 +3,93 @@
 <?import javafx.geometry.Insets?>
 <?import javafx.scene.control.*?>
 <?import javafx.scene.layout.*?>
-<?import javafx.scene.text.Font?>
-<AnchorPane prefHeight="500.0" prefWidth="855.0" xmlns="http://javafx.com/javafx/11.0.1"
-            xmlns:fx="http://javafx.com/fxml/1" fx:controller="de.hitec.nhplus.treatment.AllTreatmentController">
-    <children>
-        <TableView fx:id="tableView" editable="true" layoutX="31.0" layoutY="35.0" onMouseClicked="#handleMouseClick"
-                   prefHeight="364.0" prefWidth="825.0" AnchorPane.bottomAnchor="75.0" AnchorPane.leftAnchor="15.0"
-                   AnchorPane.rightAnchor="15.0" AnchorPane.topAnchor="80.0">
+<BorderPane
+        xmlns="http://javafx.com/javafx/11.0.1"
+        xmlns:fx="http://javafx.com/fxml/1"
+        fx:controller="de.hitec.nhplus.treatment.AllTreatmentController"
+>
+    <padding>
+        <Insets top="8" left="8" bottom="8" right="8"/>
+    </padding>
+    <center>
+        <TableView
+                fx:id="tableView"
+                editable="true"
+                onMouseClicked="#handleMouseClick"
+        >
             <columns>
-                <TableColumn fx:id="columnId" maxWidth="-1.0" minWidth="40.0" prefWidth="50.0" text="ID"/>
-                <TableColumn fx:id="columnPatientId" maxWidth="-1.0" minWidth="40.0" prefWidth="120.0"
-                             text="PatientID"/>
-                <TableColumn fx:id="columnDate" maxWidth="-1.0" minWidth="140.0" prefWidth="150.0" text="Datum"/>
-                <TableColumn fx:id="columnBegin" maxWidth="-1.0" minWidth="140.0" prefWidth="150.0" text="Beginn"/>
-                <TableColumn fx:id="columnEnd" maxWidth="-1.0" minWidth="140.0" prefWidth="150.0" text="Ende"/>
-                <TableColumn fx:id="columnDescription" maxWidth="-1.0" minWidth="200.0" prefWidth="300.0"
-                             text="Kurzbeschreibung"/>
+                <TableColumn
+                        fx:id="columnId"
+                        minWidth="40.0"
+                        text="ID"
+                />
+                <TableColumn
+                        fx:id="columnPatientId"
+                        minWidth="40.0"
+                        text="PatientID"
+                />
+                <TableColumn
+                        fx:id="columnDate"
+                        maxWidth="-1.0"
+                        minWidth="140.0"
+                        prefWidth="150.0"
+                        text="Datum"
+                />
+                <TableColumn
+                        fx:id="columnBegin"
+                        minWidth="140.0"
+                        text="Beginn"
+                />
+                <TableColumn
+                        fx:id="columnEnd"
+                        minWidth="140.0"
+                        text="Ende"
+                />
+                <TableColumn
+                        fx:id="columnDescription"
+                        minWidth="200.0"
+                        text="Kurzbeschreibung"
+                />
             </columns>
             <columnResizePolicy>
                 <TableView fx:constant="CONSTRAINED_RESIZE_POLICY"/>
             </columnResizePolicy>
         </TableView>
-        <HBox layoutX="623.0" layoutY="419.3999938964844" spacing="10.0" AnchorPane.bottomAnchor="15.0"
-              AnchorPane.leftAnchor="15.0" AnchorPane.rightAnchor="15.0">
-            <children>
-                <GridPane hgap="10.0" vgap="10.0">
-                    <columnConstraints>
-                        <ColumnConstraints halignment="LEFT" hgrow="SOMETIMES" prefWidth="200.0"/>
-                        <ColumnConstraints halignment="LEFT" hgrow="SOMETIMES" minWidth="200.0" prefWidth="200.0"/>
-                        <ColumnConstraints halignment="LEFT" hgrow="SOMETIMES" minWidth="10.0" prefWidth="160.0"/>
-                    </columnConstraints>
-                    <rowConstraints>
-                        <RowConstraints minHeight="10.0" prefHeight="30.0" vgrow="SOMETIMES"/>
-                    </rowConstraints>
-                    <children>
-                        <Button fx:id="buttonNewTreament" mnemonicParsing="false" onAction="#handleNewTreatment"
-                                prefWidth="200.0" text="neue Behandlung anlegen" GridPane.columnIndex="1"/>
-                        <ComboBox fx:id="comboBoxPatientSelection" minWidth="160.0" onAction="#handleComboBox"
-                                  prefWidth="200.0"/>
-                        <Button fx:id="buttonDelete" mnemonicParsing="false" onAction="#handleDelete" prefWidth="200.0"
-                                text="Löschen" GridPane.columnIndex="2"/>
-                    </children>
-                    <padding>
-                        <Insets right="10.0"/>
-                    </padding>
-                    <HBox.margin>
-                        <Insets/>
-                    </HBox.margin>
-                </GridPane>
-                <HBox prefWidth="190.0" spacing="10.0"/>
-            </children>
-        </HBox>
-        <HBox alignment="TOP_CENTER" layoutX="10.0" layoutY="10.0" prefWidth="200.0" spacing="25.0"
-              AnchorPane.leftAnchor="15.0" AnchorPane.rightAnchor="15.0" AnchorPane.topAnchor="5.0">
-            <children>
-                <Label alignment="CENTER" contentDisplay="CENTER" minWidth="400.0" text="Behandlungen"
-                       textAlignment="CENTER">
-                    <font>
-                        <Font size="36.0"/>
-                    </font>
-                </Label>
-            </children>
-        </HBox>
-    </children>
-    <padding>
-        <Insets top="10.0"/>
-    </padding>
-</AnchorPane>
+    </center>
+    <bottom>
+        <BorderPane>
+            <BorderPane.margin>
+                <Insets top="8.0"/>
+            </BorderPane.margin>
+            <center>
+                <HBox spacing="8.0">
+                    <Button
+                            fx:id="buttonNewTreament"
+                            mnemonicParsing="false"
+                            onAction="#handleNewTreatment"
+                            prefWidth="200.0"
+                            text="neue Behandlung anlegen"
+                            GridPane.columnIndex="1"
+                    />
+                    <ComboBox
+                            fx:id="comboBoxPatientSelection"
+                            minWidth="160.0"
+                            onAction="#handleComboBox"
+                            prefWidth="200.0"/>
+
+                </HBox>
+            </center>
+            <right>
+                <Button
+                        fx:id="buttonDelete"
+                        mnemonicParsing="false"
+                        onAction="#handleDelete"
+                        prefWidth="200.0"
+                        text="Löschen"
+                        GridPane.columnIndex="2"
+                />
+            </right>
+        </BorderPane>
+
+    </bottom>
+</BorderPane>