diff --git a/src/main/resources/templates/authentication.html b/src/main/resources/templates/authentication.html
index d99335e..d9b2341 100644
--- a/src/main/resources/templates/authentication.html
+++ b/src/main/resources/templates/authentication.html
@@ -4,6 +4,8 @@
 <head>
 	<meta charset="UTF-8">
 	<title>認証</title>
+	<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 
 <body class="pb-5 pt-5">
diff --git a/src/main/resources/templates/login.html b/src/main/resources/templates/login.html
index b49f376..472e628 100644
--- a/src/main/resources/templates/login.html
+++ b/src/main/resources/templates/login.html
@@ -3,6 +3,8 @@
 <head>
 <meta charset="UTF-8">
 <title>ログイン</title>
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 <body class="pb-5 pt-5">
 	<div th:replace="~{header :: header}">
diff --git a/src/main/resources/templates/password_reset.html b/src/main/resources/templates/password_reset.html
index b2abc42..07d4ffb 100644
--- a/src/main/resources/templates/password_reset.html
+++ b/src/main/resources/templates/password_reset.html
@@ -3,6 +3,8 @@
 <head>
 <meta charset="UTF-8">
 <title>パスワード再設定</title>
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 <body>
 <!--<body class="pb-5 pt-5">-->
diff --git a/src/main/resources/templates/profile.html b/src/main/resources/templates/profile.html
index 0fe082b..8a9c72b 100644
--- a/src/main/resources/templates/profile.html
+++ b/src/main/resources/templates/profile.html
@@ -3,6 +3,8 @@
 <head>
 <meta charset="UTF-8">
 <title>プロフィール</title>
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 <body class="pb-5 pt-5">
 	
diff --git a/src/main/resources/templates/profile_edit.html b/src/main/resources/templates/profile_edit.html
index d82c709..ec7d81e 100644
--- a/src/main/resources/templates/profile_edit.html
+++ b/src/main/resources/templates/profile_edit.html
@@ -3,6 +3,8 @@
 <head>
 <meta charset="UTF-8">
 <title>プロフィール編集</title>
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 <body class="pb-5 pt-5">
 	
diff --git a/src/main/resources/templates/user_register.html b/src/main/resources/templates/user_register.html
index c6ec36b..dee9c92 100644
--- a/src/main/resources/templates/user_register.html
+++ b/src/main/resources/templates/user_register.html
@@ -3,6 +3,8 @@
 <head>
 <meta charset="UTF-8">
 <title>新規会員登録</title>
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 <body class="pb-5 pt-5">
 	<div th:replace="~{header :: header}">
diff --git a/src/main/resources/templates/user_register_confirm.html b/src/main/resources/templates/user_register_confirm.html
index 5356eb7..581457e 100644
--- a/src/main/resources/templates/user_register_confirm.html
+++ b/src/main/resources/templates/user_register_confirm.html
@@ -4,6 +4,8 @@
 <head>
 	<meta charset="UTF-8">
 	<title>新規会員登録確認</title>
+	<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 
 <body class="pb-5 pt-5">
diff --git a/src/main/resources/templates/user_register_return.html b/src/main/resources/templates/user_register_return.html
index 4ecd680..04fb234 100644
--- a/src/main/resources/templates/user_register_return.html
+++ b/src/main/resources/templates/user_register_return.html
@@ -3,6 +3,8 @@
 <head>
 <meta charset="UTF-8">
 <title>新規会員登録</title>
+<link href="https://cdn.jsdelivr.net/npm/bootstrap@5.3.7/dist/css/bootstrap.min.css" rel="stylesheet">
+
 </head>
 <body class="pb-5 pt-5">
 	<div th:replace="~{header :: header}">