diff --git a/frontend/firebase-init.js b/frontend/firebase-init.js
index 76d856bc..86813f5c 100644
--- a/frontend/firebase-init.js
+++ b/frontend/firebase-init.js
@@ -48,4 +48,4 @@ const loadFirebaseAuth = () => {
     return authModulePromise;
 };
 
-export { loadFirebaseAuth, authDomainInputs };
+export { isFireBaseSet, loadFirebaseAuth, authDomainInputs };
diff --git a/frontend/locales/en.json b/frontend/locales/en.json
index 87f5962a..34e81d91 100644
--- a/frontend/locales/en.json
+++ b/frontend/locales/en.json
@@ -192,7 +192,6 @@
   },
   "nav": {
     "id": "nav",
-    "Title": "IPCheck.ing",
     "Navigation": "Navigation",
     "Home": "Home",
     "IPInfo": "IP Infos",
@@ -201,9 +200,6 @@
     "WebRTC": "WebRTC Leak Test",
     "DNSLeakTest": "DNS Leak Test",
     "SpeedTest": "Speed Test",
-    "PingTest": "Global Latency",
-    "MTRTest": "MTR Test",
-    "RuleTest": "Rule Test",
     "AdvancedTools": "Advanced Tools",
     "SearchDocs": "Search docs…",
     "DocsToolConfirm": "Share your current test results?",
diff --git a/frontend/locales/fr.json b/frontend/locales/fr.json
index a7ce2903..463382cd 100644
--- a/frontend/locales/fr.json
+++ b/frontend/locales/fr.json
@@ -192,7 +192,6 @@
   },
   "nav": {
     "id": "nav",
-    "Title": "IPCheck.ing",
     "Navigation": "Navigation",
     "Home": "Accueil",
     "IPInfo": "Infos IP",
@@ -201,9 +200,6 @@
     "WebRTC": "Test WebRTC Leak",
     "DNSLeakTest": "Test de fuite DNS",
     "SpeedTest": "Test de vitesse",
-    "PingTest": "Latence mondiale",
-    "MTRTest": "Test MTR",
-    "RuleTest": "Test de règles",
     "AdvancedTools": "Outils avancés",
     "SearchDocs": "Rechercher dans la doc…",
     "DocsToolConfirm": "Partager vos résultats actuels ?",
diff --git a/frontend/locales/pt-BR.json b/frontend/locales/pt-BR.json
index 0862fea1..be7388f2 100644
--- a/frontend/locales/pt-BR.json
+++ b/frontend/locales/pt-BR.json
@@ -192,7 +192,6 @@
   },
   "nav": {
     "id": "nav",
-    "Title": "IPCheck.ing",
     "Navigation": "Navegação",
     "Home": "Início",
     "IPInfo": "Dados de IP",
@@ -201,9 +200,6 @@
     "WebRTC": "Vazamento WebRTC",
     "DNSLeakTest": "Vazamento de DNS",
     "SpeedTest": "Velocidade",
-    "PingTest": "Latência global",
-    "MTRTest": "Teste MTR",
-    "RuleTest": "Teste de regras",
     "AdvancedTools": "Ferramentas avançadas",
     "SearchDocs": "Pesquisar na documentação…",
     "DocsToolConfirm": "Compartilhar seus resultados atuais dos testes?",
diff --git a/frontend/locales/ru.json b/frontend/locales/ru.json
index 0c4fb8d4..43431113 100644
--- a/frontend/locales/ru.json
+++ b/frontend/locales/ru.json
@@ -192,7 +192,6 @@
   },
   "nav": {
     "id": "nav",
-    "Title": "IPCheck.ing",
     "Navigation": "Навигация",
     "Home": "Главная",
     "IPInfo": "Сведения об IP",
@@ -201,9 +200,6 @@
     "WebRTC": "Тест утечки WebRTC",
     "DNSLeakTest": "Тест утечки DNS",
     "SpeedTest": "Тест скорости",
-    "PingTest": "Глобальная задержка",
-    "MTRTest": "Тест MTR",
-    "RuleTest": "Проверка правил",
     "AdvancedTools": "Расширенные инструменты",
     "SearchDocs": "Поиск по документации…",
     "DocsToolConfirm": "Показать ваши текущие результаты?",
diff --git a/frontend/locales/zh-TW.json b/frontend/locales/zh-TW.json
index 7698103f..39b370ee 100644
--- a/frontend/locales/zh-TW.json
+++ b/frontend/locales/zh-TW.json
@@ -192,7 +192,6 @@
   },
   "nav": {
     "id": "nav",
-    "Title": "IPCheck.ing",
     "Navigation": "導覽",
     "Home": "首頁",
     "IPInfo": "IP 資訊",
@@ -201,9 +200,6 @@
     "WebRTC": "WebRTC 洩漏測試",
     "DNSLeakTest": "DNS 洩漏測試",
     "SpeedTest": "網速測試",
-    "PingTest": "全球延遲",
-    "MTRTest": "MTR 測試",
-    "RuleTest": "分流測試",
     "AdvancedTools": "進階工具",
     "SearchDocs": "搜尋文件…",
     "DocsToolConfirm": "要讓助手查看目前的測試結果嗎？",
diff --git a/frontend/locales/zh.json b/frontend/locales/zh.json
index 8d024fc8..c0d0c316 100644
--- a/frontend/locales/zh.json
+++ b/frontend/locales/zh.json
@@ -192,7 +192,6 @@
   },
   "nav": {
     "id": "nav",
-    "Title": "IPCheck.ing",
     "Navigation": "导航",
     "Home": "首页",
     "IPInfo": "IP 信息",
@@ -201,9 +200,6 @@
     "WebRTC": "WebRTC 泄露测试",
     "DNSLeakTest": "DNS 泄露测试",
     "SpeedTest": "网速测试",
-    "PingTest": "全球延迟",
-    "MTRTest": "MTR 测试",
-    "RuleTest": "分流测试",
     "AdvancedTools": "高级工具",
     "SearchDocs": "搜索文档…",
     "DocsToolConfirm": "把当前的检测结果给助手看？",
diff --git a/frontend/main.js b/frontend/main.js
index 314e79c9..56874c22 100644
--- a/frontend/main.js
+++ b/frontend/main.js
@@ -127,8 +127,6 @@ analytics.setUserProperties({
 });
 unregisterLegacyServiceWorker();
 
-// Check Firebase environment
-store.checkFirebaseEnv();
 
 // Backend configs load fire-and-forget: components read `store.configs`
 // reactively, so the first render never waits on this round trip.
diff --git a/frontend/store.js b/frontend/store.js
index 7ba20098..f4a1d2f3 100644
--- a/frontend/store.js
+++ b/frontend/store.js
@@ -1,6 +1,6 @@
 // store.js
 import { defineStore } from 'pinia';
-import { loadFirebaseAuth, authDomainInputs } from './firebase-init.js';
+import { isFireBaseSet, loadFirebaseAuth, authDomainInputs } from './firebase-init.js';
 import { signInProvidersFor } from './utils/auth-domain.js';
 import { writeAuthHint } from './utils/auth-hint.js';
 import { markPendingRedirectSignIn, shouldFallBackToRedirect, takePendingRedirectSignIn } from './utils/auth-redirect.js';
@@ -67,7 +67,7 @@ export const useMainStore = defineStore('main', {
       ipv6Domain: import.meta.env?.VITE_CURL_IPV6_DOMAIN,
       ipv64Domain: import.meta.env?.VITE_CURL_IPV64_DOMAIN,
     },
-    isFireBaseSet: false,
+    isFireBaseSet,
     openSheet: null,
     loadingStatus: createLoadingStatus(),
     isDarkMode: false,
@@ -259,16 +259,6 @@ export const useMainStore = defineStore('main', {
     changeSection(section) {
       this.currentSection = section;
     },
-    // check Firebase environment
-    checkFirebaseEnv() {
-      const env = import.meta.env ?? {};
-      const envConfigs = {
-        key: env.VITE_FIREBASE_API_KEY,
-        domain: env.VITE_FIREBASE_AUTH_DOMAIN,
-        project: env.VITE_FIREBASE_PROJECT_ID,
-      }
-      this.isFireBaseSet = !!envConfigs.key && !!envConfigs.domain && !!envConfigs.project;
-    },
     // sign in with Google
     async signInWithGoogle() {
       await this.signInWithProvider('google');
diff --git a/frontend/style/style.css b/frontend/style/style.css
index 9a17eb66..117076d2 100644
--- a/frontend/style/style.css
+++ b/frontend/style/style.css
@@ -68,10 +68,9 @@
   --input: oklch(0.922 0 0);
   --ring: oklch(0.708 0 0);
   --radius: 0.5rem;
-  /* Canonical page background (the installed app's Nav in its mobile
-     `bg-page-bg` variant reads it). Must stay in sync with the literal
-     hex values in: index.html inline `html { background }`, index.html
-     <meta theme-color>, public/manifest.webmanifest. */
+  /* Canonical page background: the installed app's Nav (`bg-page-bg`) and
+     the manifest's theme_color use it. index.html's html background and
+     theme-color are tuned separately on purpose. */
   --page-bg: #f4f4f4;
 }