diff --git a/src/main/java/dev/sillyangel/calc/Calculator.java b/src/main/java/dev/sillyangel/calc/Calculator.java
index 14d1aa0..de15121 100644
--- a/src/main/java/dev/sillyangel/calc/Calculator.java
+++ b/src/main/java/dev/sillyangel/calc/Calculator.java
@@ -17,6 +17,7 @@ import javax.swing.GroupLayout.Alignment;
 import javax.swing.*;
 import com.formdev.flatlaf.FlatDarculaLaf;
 import com.formdev.flatlaf.FlatIntelliJLaf;
+import java.util.prefs.Preferences;
 import com.formdev.flatlaf.FlatLaf;
 import com.formdev.flatlaf.extras.FlatAnimatedLafChange;
 import com.formdev.flatlaf.FlatClientProperties;
@@ -486,9 +487,85 @@ public class Calculator extends JFrame implements KeyListener {
 
 	}
 	private void PreferencesAction() {
-		System.out.println("preferences panel are open");
+    	JDialog dialog = new JDialog(this, "Preferences", true);
+    	dialog.setSize(320, 220);
+    	dialog.setLocationRelativeTo(this);
+    	dialog.setLayout(new BorderLayout(10, 10));
 
+    	JPanel panel = new JPanel();
+    	panel.setBorder(new EmptyBorder(10, 10, 10, 10));
+    	panel.setLayout(new GridLayout(0, 2, 8, 8));
+
+    	// Theme selector
+    	JComboBox<String> themeBox = new JComboBox<>(new String[]{"Dark", "Light"});
+    	themeBox.setSelectedItem(prefs.get(PREF_THEME, "Dark"));
+
+    	// Font size
+    	JSpinner fontSizeSpinner = new JSpinner(
+        	new SpinnerNumberModel(
+           		prefs.getInt(PREF_FONT_SIZE, 22),
+            	12, 48, 1
+        	)
+  		);
+
+    // Always on top
+    	JCheckBox alwaysOnTopBox = new JCheckBox(
+        	"Always on top",
+        	prefs.getBoolean(PREF_ALWAYS_ON_TOP, false)
+   		);
+
+ 		panel.add(new JLabel("Theme"));
+    	panel.add(themeBox);
+
+    	panel.add(new JLabel("Font size"));
+    	panel.add(fontSizeSpinner);
+
+    	panel.add(new JLabel(""));
+    	panel.add(alwaysOnTopBox);
+
+    	JButton apply = new JButton("Apply");
+    	JButton close = new JButton("Close");
+
+    	apply.addActionListener(e -> {
+        	String theme = (String) themeBox.getSelectedItem();
+        	int fontSize = (int) fontSizeSpinner.getValue();
+        	boolean alwaysOnTop = alwaysOnTopBox.isSelected();
+
+        	prefs.put(PREF_THEME, theme);
+        	prefs.putInt(PREF_FONT_SIZE, fontSize);
+        	prefs.putBoolean(PREF_ALWAYS_ON_TOP, alwaysOnTop);
+
+        	applyPreferences(theme, fontSize, alwaysOnTop);
+    	});
+
+    	close.addActionListener(e -> dialog.dispose());
+
+    	JPanel buttons = new JPanel(new FlowLayout(FlowLayout.RIGHT));
+    	buttons.add(apply);
+    	buttons.add(close);
+
+    	dialog.add(panel, BorderLayout.CENTER);
+    	dialog.add(buttons, BorderLayout.SOUTH);
+    	dialog.setVisible(true);
 	}
+	private void applyPreferences(String theme, int fontSize, boolean alwaysOnTop) {
+    	display.setFont(new Font("Segoe UI", Font.PLAIN, fontSize));
+    	setAlwaysOnTop(alwaysOnTop);
+
+    	try {
+        	FlatAnimatedLafChange.showSnapshot();
+        	if ("Light".equals(theme)) {
+	            	FlatIntelliJLaf.setup();
+    	    } else {
+        	    FlatDarculaLaf.setup();
+	        }
+    	    FlatLaf.updateUI();
+        	FlatAnimatedLafChange.hideSnapshotWithAnimation();
+    	} catch (Exception ex) {
+        	ex.printStackTrace();
+    	}
+	}
+
 	private void aboutActionPerformed() {
 		JLabel titleLabel = new JLabel( "Angel's Awesome Calculator" );
 		titleLabel.putClientProperty( FlatClientProperties.STYLE_CLASS, "h1" );
@@ -631,11 +708,43 @@ public class Calculator extends JFrame implements KeyListener {
 		resultVisible = true;
 		display.setText(""+result);
 	}
-	private void changeThemes(String theme) {
-		// something like
-		// https://github.com/DJ-Raven/raven-java-swing-tutorial-project/blob/main/dark-light-switch/src/raven/themes/Test.java#L106
+
+	private void loadPreferences() {
+    	int fontSize = prefs.getInt(PREF_FONT_SIZE, 22);
+    	boolean alwaysOnTop = prefs.getBoolean(PREF_ALWAYS_ON_TOP, false);
+
+    	display.setFont(new Font("Segoe UI", Font.PLAIN, fontSize));
+    	setAlwaysOnTop(alwaysOnTop);
 	}
 
+	private void changeThemes(String theme) {
+    	boolean dark = switch (theme.toLowerCase()) {
+	        case "dark", "darcula", "macdarkblue", "macdarkred" -> true;
+    	    default -> false;
+    	};
+
+	    // Only switch if needed
+    	if (FlatLaf.isLafDark() != dark || isCustomMacTheme(theme)) {
+        	EventQueue.invokeLater(() -> {
+            	FlatAnimatedLafChange.showSnapshot();
+            	try {
+                	switch (theme.toLowerCase()) {
+                    	case "light" -> FlatIntelliJLaf.setup();
+                    	case "dark", "darcula" -> FlatDarculaLaf.setup();
+                    	case "macdarkblue" -> MacDarkBlue.setup();
+                    	case "macdarkred" -> MacDarkRed.setup();
+                    	default -> FlatDarculaLaf.setup();
+                	}
+                	FlatLaf.updateUI();
+            	} finally {
+                	FlatAnimatedLafChange.hideSnapshotWithAnimation();
+	            }
+    	    });
+    	}
+	}
+
+
+
     // Implement the keyPressed method
     @Override
     public void keyPressed(KeyEvent e) {