diff --git a/src/features/homepage/components/MessagePaper.tsx b/src/features/homepage/components/MessagePaper.tsx
index 92514ed..1034fa3 100644
--- a/src/features/homepage/components/MessagePaper.tsx
+++ b/src/features/homepage/components/MessagePaper.tsx
@@ -2,7 +2,7 @@ import { useState, useEffect } from 'react';
 import { Paper, Typography, Stack, Button, Divider } from '@mui/material';
 import { useAppStateStore } from '@/store/appStateStore';
 
-const isElectron = navigator.userAgent.indexOf('Electron') >= 0;
+const isElectron = navigator.userAgent.includes('Electron');
 
 export const MessagePaper = () => {
   const [currentVersion, setCurrentVersion] = useState('');
@@ -24,7 +24,7 @@ export const MessagePaper = () => {
 
     // 現在のアプリバージョンを取得
     const fetchCurrentVersion = async () => {
-      // @ts-expect-error ElectronAPI
+      //@ts-expect-error Electron
       const version = await window.electron.getAppVersion();
       setCurrentVersion(version);
     };
@@ -72,7 +72,7 @@ export const MessagePaper = () => {
 
   return (
     <Stack sx={{ width: '100%', maxWidth: 400, margin: 'auto', marginTop: 4 }}>
-      {isWeb && (
+      {isWeb && !isElectron && (
         <>
           <Paper>
             <Typography variant='body2' sx={{ textAlign: 'left', p: 2 }} gutterBottom>
@@ -96,7 +96,7 @@ export const MessagePaper = () => {
         </>
       )}
       {isElectron && (
-        <Paper sx={{ maxWidth: 400, margin: 'auto', marginTop: 4 }}>
+        <Paper sx={{ width: '100%', maxWidth: 400, margin: 'auto', marginTop: 4 }}>
           <Typography variant='body2' sx={{ textAlign: 'left', p: 2 }} gutterBottom>
             ver{currentVersion}
           </Typography>
@@ -130,7 +130,11 @@ export const MessagePaper = () => {
           ©{new Date().getFullYear()} Jun Murakami
         </a>{' '}
         |{' '}
-        <a href='https://github.com/Jun-Murakami/TaskTrees' target='_blank' rel='noreferrer'>
+        <a
+          href={isElectron ? 'https://github.com/Jun-Murakami/TaskTrees-Electron' : 'https://github.com/Jun-Murakami/TaskTrees'}
+          target='_blank'
+          rel='noreferrer'
+        >
           GitHub
         </a>{' '}
         |{' '}
diff --git a/src/features/homepage/hooks/useAuth.ts b/src/features/homepage/hooks/useAuth.ts
index 35d5004..fda361e 100644
--- a/src/features/homepage/hooks/useAuth.ts
+++ b/src/features/homepage/hooks/useAuth.ts
@@ -61,7 +61,7 @@ type UserComact = {
   email: string | null;
 };
 
-const isElectron = navigator.userAgent.indexOf('Electron') >= 0;
+const isElectron = navigator.userAgent.includes('Electron');
 
 export const useAuth = () => {
   const isOffline = useAppStateStore((state) => state.isOffline);
@@ -137,7 +137,7 @@ export const useAuth = () => {
           setSystemMessage(null);
         })
         .catch((error) => {
-          setSystemMessage('ログインに失敗しました。Code:100\n\n' + error.code);
+          setSystemMessage('ログインに失敗しました。Code:99\n\n' + error);
           setIsLoading(false);
         });
     }
@@ -175,11 +175,16 @@ export const useAuth = () => {
         return;
       }
     } else if (isElectron) {
-      // @ts-expect-error ElectronAPI
-      await window.electron.openOAuthURL(`https://${import.meta.env.VITE_AUTH_DOMAIN}/auth/google`).then((credential) => {
-        handleCredentialLogin(credential);
-      }).catch((error: FirebaseError) => {
-        setSystemMessage('Googleログインに失敗しました。Code:102\n\n' + error.code);
+      //@ts-expect-error Electron
+      await window.electron.openOAuthURL(`https://${import.meta.env.VITE_AUTH_DOMAIN}/auth/google`).then((credential: OAuthCredential) => {
+        const googleCredential = GoogleAuthProvider.credential(credential.idToken, credential.accessToken);
+        handleCredentialLogin(googleCredential);
+      }).catch((error: Error) => {
+        if (error.message.includes('closed-by-user')) {
+          setSystemMessage('Googleログインがキャンセルされました。');
+        } else {
+          setSystemMessage('Googleログインに失敗しました。Code:102\n\n' + (error instanceof Error ? error.message : 'Unknown error'));
+        }
         setIsLoading(false);
       });
     } else {
@@ -227,11 +232,16 @@ export const useAuth = () => {
         return;
       }
     } else if (isElectron) {
-      // @ts-expect-error ElectronAPI
-      await window.electron.openOAuthURL(`https://${import.meta.env.VITE_AUTH_DOMAIN}/auth/apple`).then((credential) => {
-        handleCredentialLogin(credential);
-      }).catch((error: FirebaseError) => {
-        setSystemMessage('Appleログインに失敗しました。Code:107\n\n' + error.code);
+      //@ts-expect-error Electron
+      await window.electron.openOAuthURL(`https://${import.meta.env.VITE_AUTH_DOMAIN}/auth/apple`).then((credential: OAuthCredential) => {
+        const appleCredential = OAuthProvider.credentialFromJSON(credential);
+        handleCredentialLogin(appleCredential);
+      }).catch((error: Error) => {
+        if (error.message.includes('closed-by-user')) {
+          setSystemMessage('Appleログインがキャンセルされました。');
+        } else {
+          setSystemMessage('Appleログインに失敗しました。Code:107\n\n' + (error instanceof Error ? error.message : 'Unknown error'));
+        }
         setIsLoading(false);
       });
     } else {