diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/EntryPoint.java b/HMCL/src/main/java/org/jackhuang/hmcl/EntryPoint.java
index 52391c805..83623c86d 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/EntryPoint.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/EntryPoint.java
@@ -51,8 +51,11 @@ public final class EntryPoint {
 
         setupJavaFXVMOptions();
 
-        if (OperatingSystem.CURRENT_OS == OperatingSystem.MACOS && !isInsideMacAppBundle())
-            initIcon();
+        if (OperatingSystem.CURRENT_OS == OperatingSystem.MACOS) {
+            System.getProperties().putIfAbsent("apple.awt.application.appearance", "system");
+            if (!isInsideMacAppBundle())
+                initIcon();
+        }
 
         checkJavaFX();
         verifyJavaFX();
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/theme/Themes.java b/HMCL/src/main/java/org/jackhuang/hmcl/theme/Themes.java
index 0ad793038..3e01293ef 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/theme/Themes.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/theme/Themes.java
@@ -32,6 +32,9 @@ import org.glavo.monetfx.beans.property.ColorSchemeProperty;
 import org.glavo.monetfx.beans.property.ReadOnlyColorSchemeProperty;
 import org.glavo.monetfx.beans.property.SimpleColorSchemeProperty;
 import org.jackhuang.hmcl.ui.FXUtils;
+import org.jackhuang.hmcl.util.platform.OperatingSystem;
+import org.jackhuang.hmcl.util.platform.SystemUtils;
+import org.jackhuang.hmcl.util.platform.windows.WinReg;
 
 import java.util.ArrayList;
 import java.util.List;
@@ -65,7 +68,7 @@ public final class Themes {
                     if (FXUtils.DARK_MODE != null) {
                         yield FXUtils.DARK_MODE.get() ? Brightness.DARK : Brightness.LIGHT;
                     } else {
-                        yield Brightness.DEFAULT;
+                        yield getDefaultBrightness();
                     }
                 }
                 case "dark" -> Brightness.DARK;
@@ -97,6 +100,34 @@ public final class Themes {
         theme.addListener(listener);
     }
 
+    private static Brightness defaultBrightness;
+
+    private static Brightness getDefaultBrightness() {
+        if (defaultBrightness != null)
+            return defaultBrightness;
+
+        Brightness brightness = Brightness.DEFAULT;
+        if (OperatingSystem.CURRENT_OS == OperatingSystem.WINDOWS) {
+            WinReg reg = WinReg.INSTANCE;
+            if (reg != null) {
+                Object appsUseLightTheme = reg.queryValue(WinReg.HKEY.HKEY_CURRENT_USER, "Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize", "AppsUseLightTheme");
+                if (appsUseLightTheme instanceof Integer value) {
+                    brightness = value == 0 ? Brightness.DARK : Brightness.LIGHT;
+                }
+            }
+        } else if (OperatingSystem.CURRENT_OS == OperatingSystem.MACOS) {
+            try {
+                String result = SystemUtils.run("/usr/bin/defaults", "read", "-g", "AppleInterfaceStyle").trim();
+                brightness = "Dark".equalsIgnoreCase(result) ? Brightness.DARK : Brightness.LIGHT;
+            } catch (Exception e) {
+                // If the key does not exist, it means Light mode is used
+                brightness = Brightness.LIGHT;
+            }
+        }
+
+        return defaultBrightness = brightness;
+    }
+
     public static ObjectExpression<Theme> themeProperty() {
         return theme;
     }
diff --git a/HMCL/src/main/java/org/jackhuang/hmcl/ui/main/PersonalizationPage.java b/HMCL/src/main/java/org/jackhuang/hmcl/ui/main/PersonalizationPage.java
index b03bed7ca..d0f1e3bc8 100644
--- a/HMCL/src/main/java/org/jackhuang/hmcl/ui/main/PersonalizationPage.java
+++ b/HMCL/src/main/java/org/jackhuang/hmcl/ui/main/PersonalizationPage.java
@@ -44,7 +44,6 @@ import org.jackhuang.hmcl.util.Lang;
 import org.jackhuang.hmcl.util.javafx.SafeStringConverter;
 
 import java.util.Arrays;
-import java.util.List;
 import java.util.Locale;
 import java.util.Optional;
 
@@ -87,11 +86,8 @@ public class PersonalizationPage extends StackPane {
 
             brightnessPane.setLeft(left);
 
-            JFXComboBox<String> cboBrightness = new JFXComboBox<>(FXCollections.observableArrayList(
-                    FXUtils.DARK_MODE != null
-                            ? List.of("auto", "light", "dark")
-                            : List.of("light", "dark")
-            ));
+            JFXComboBox<String> cboBrightness = new JFXComboBox<>();
+            cboBrightness.getItems().setAll("auto", "light", "dark");
             cboBrightness.setConverter(FXUtils.stringConverter(name -> i18n("settings.launcher.brightness." + name)));
             cboBrightness.valueProperty().bindBidirectional(config().themeBrightnessProperty());
             brightnessPane.setRight(cboBrightness);