body {
    margin: 0;
    padding: 20px;
    font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", Roboto, "Helvetica Neue", Arial, sans-serif;
}

.chat-container {
    max-width: 800px;
    margin: 0 auto;
    display: flex;
    flex-direction: column;
    height: 90vh;
}

.chat-messages {
    flex: 1;
    overflow-y: auto;
    padding: 20px;
    background: #f5f5f5;
    border-radius: 8px;
    margin-bottom: 20px;
}

.message {
    margin-bottom: 15px;
    padding: 10px 15px;
    border-radius: 8px;
    max-width: 80%;
}

.user-message {
    background: #007bff;
    color: white;
    margin-left: auto;
}

.assistant-message {
    background: white;
    color: #333;
}

.input-container {
    position: relative;
    display: flex;
    gap: 10px;
}

#user-input {
    flex: 1;
    height: 100px;
    padding: 15px;
    border: 1px solid #ddd;
    border-radius: 8px;
    resize: none;
    font-size: 16px;
    box-sizing: border-box;
}

#user-input:focus {
    outline: none;
    border-color: #007bff;
}

.send-button {
    padding: 0 20px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 8px;
    cursor: pointer;
    font-size: 16px;
    transition: background-color 0.2s;
}

.send-button:hover {
    background-color: #0056b3;
}

.send-button:active {
    background-color: #004085;
}

/* ログインページのスタイル */
.login-container {
    max-width: 400px;
    margin: 50px auto;
    padding: 20px;
    background-color: #fff;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

.login-form {
    display: flex;
    flex-direction: column;
    gap: 20px;
}

.form-group {
    display: flex;
    flex-direction: column;
    gap: 8px;
}

.form-group label {
    font-weight: bold;
    color: #333;
}

.form-group input {
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    font-size: 16px;
}

.login-form button {
    padding: 12px;
    background-color: #007bff;
    color: white;
    border: none;
    border-radius: 4px;
    font-size: 16px;
    cursor: pointer;
    transition: background-color 0.2s;
}

.login-form button:hover {
    background-color: #0056b3;
}

.signup-link {
    margin-top: 20px;
    text-align: center;
    color: #666;
}

.signup-link a {
    color: #007bff;
    text-decoration: none;
}

.signup-link a:hover {
    text-decoration: underline;
}

/* フォームのヘルプテキスト */
.form-text {
    font-size: 0.8em;
    color: #666;
    margin-top: 4px;
}

/* エラーメッセージ */
.error-message {
    color: #dc3545;
    font-size: 0.9em;
    margin-top: 4px;
}

/* 成功メッセージ */
.success-message {
    color: #28a745;
    font-size: 0.9em;
    margin-top: 4px;
    text-align: center;
    padding: 10px;
    background-color: #d4edda;
    border-radius: 4px;
    margin-bottom: 20px;
}