From c83586cfc0d37afe1e6ce2d6ce7990b354a90065 Mon Sep 17 00:00:00 2001
From: fanfan <135687942+fanfan1233@users.noreply.github.com>
Date: Wed, 23 Sep 2026 17:05:30 +0800
Subject: [PATCH] fix(i18n): match browser locale tags precisely

---
 frontend/src/i18n.tsx | 17 +++++++++++++----
 1 file changed, 13 insertions(+), 4 deletions(-)

diff --git a/frontend/src/i18n.tsx b/frontend/src/i18n.tsx
index 4062191..d0b1aa6 100644
--- a/frontend/src/i18n.tsx
+++ b/frontend/src/i18n.tsx
@@ -285,10 +285,19 @@ const storageKey = "laya-server-locale"
 
 export function resolveLocale(languages: readonly string[]): Locale {
   for (const language of languages) {
-    const value = language.toLowerCase()
-    if (value.startsWith("zh-hant") || /^zh-(tw|hk|mo)(-|$)/.test(value)) return "zh-TW"
-    if (value.startsWith("zh")) return "zh-CN"
-    if (value.startsWith("en")) return "en"
+    let locale: Intl.Locale
+    try {
+      locale = new Intl.Locale(language)
+    } catch {
+      // Ignore malformed preferences and continue to the next supported language.
+      continue
+    }
+    if (locale.language === "zh") {
+      // An explicit script takes precedence over the region's usual script.
+      if (locale.script) return locale.script === "Hant" ? "zh-TW" : "zh-CN"
+      return ["TW", "HK", "MO"].includes(locale.region ?? "") ? "zh-TW" : "zh-CN"
+    }
+    if (locale.language === "en") return "en"
   }
   return "en"
 }