diff --git a/src/main/java/cz/kamma/kfmanager/MainApp.java b/src/main/java/cz/kamma/kfmanager/MainApp.java
index a5eb4f6..f5f728c 100644
--- a/src/main/java/cz/kamma/kfmanager/MainApp.java
+++ b/src/main/java/cz/kamma/kfmanager/MainApp.java
@@ -88,7 +88,7 @@ public class MainApp {
 
     private static boolean isWindowsDarkMode() {
         try {
-            Process process = Runtime.getRuntime().exec("reg query \"HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize\" /v AppsUseLightTheme");
+            Process process = new ProcessBuilder("reg", "query", "HKEY_CURRENT_USER\\Software\\Microsoft\\Windows\\CurrentVersion\\Themes\\Personalize", "/v", "AppsUseLightTheme").start();
             BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()));
             String line;
             while ((line = reader.readLine()) != null) {
@@ -105,14 +105,14 @@ public class MainApp {
     private static boolean isLinuxDarkMode() {
         try {
             // Check for GNOME/Cinnamon/MATE dark mode preference via gsettings
-            Process process = Runtime.getRuntime().exec(new String[]{"gsettings", "get", "org.gnome.desktop.interface", "color-scheme"});
+            Process process = new ProcessBuilder("gsettings", "get", "org.gnome.desktop.interface", "color-scheme").start();
             try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
                 String line = reader.readLine();
                 if (line != null && line.contains("dark")) return true;
             }
 
             // Fallback: Check GTK theme name
-            process = Runtime.getRuntime().exec(new String[]{"gsettings", "get", "org.gnome.desktop.interface", "gtk-theme"});
+            process = new ProcessBuilder("gsettings", "get", "org.gnome.desktop.interface", "gtk-theme").start();
             try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
                 String line = reader.readLine();
                 if (line != null && line.toLowerCase().contains("dark")) return true;
@@ -125,7 +125,7 @@ public class MainApp {
 
     private static boolean isMacDarkMode() {
         try {
-            Process process = Runtime.getRuntime().exec(new String[]{"defaults", "read", "-g", "AppleInterfaceStyle"});
+            Process process = new ProcessBuilder("defaults", "read", "-g", "AppleInterfaceStyle").start();
             try (BufferedReader reader = new BufferedReader(new InputStreamReader(process.getInputStream()))) {
                 String line = reader.readLine();
                 return line != null && line.contains("Dark");