diff --git a/Commons/I18n.qml b/Commons/I18n.qml
index 20e59297..31319011 100644
--- a/Commons/I18n.qml
+++ b/Commons/I18n.qml
@@ -170,11 +170,24 @@ Singleton {
 
     // Detect user's favorite locale - languages
     for (var i = 0; i < Qt.locale().uiLanguages.length; i++) {
-      const userLang = Qt.locale().uiLanguages[i].substring(0, 2)
-      if (availableLanguages.includes(userLang)) {
-        setLanguage(userLang)
+      const fullUserLang = Qt.locale().uiLanguages[i]
+      
+      // Try full code match (such as zh CN, en US)
+      if (availableLanguages.includes(fullUserLang)) {
+        Logger.log("I18n", `Exact match found: "${fullUserLang}"`)
+        setLanguage(fullUserLang)
         return
       }
+      
+      // If full code match fails, try short code matching (such as zh, en)
+      const shortUserLang = fullUserLang.substring(0, 2)
+      if (availableLanguages.includes(shortUserLang)) {
+        Logger.log("I18n", `Short code match found: "${shortUserLang}" from "${fullUserLang}"`)
+        setLanguage(shortUserLang)
+        return
+      }
+      
+      Logger.log("I18n", `No match for system language: "${fullUserLang}"`)
     }
 
     // Fallback to first available language (preferably "en" if available)