body {
    font-family: Arial, sans-serif;
    margin: 20px;
    background-color: #f4f4f4;
    color: #333;
}

.container {
    max-width: 800px;
    margin: 0 auto;
    background-color: #fff;
    padding: 20px;
    border-radius: 8px;
    box-shadow: 0 2px 4px rgba(0, 0, 0, 0.1);
}

h1, h2, h3 {
    color: #0056b3;
    margin-top: 25px;
    margin-bottom: 15px;
}

.form-group {
    margin-bottom: 15px;
}

.form-group label {
    display: block;
    margin-bottom: 5px;
    font-weight: bold;
}

.form-group input[type="text"],
.form-group input[type="number"],
.form-group input[type="password"],
.form-group input[type="url"],
.form-group select,
.form-group textarea {
    width: 100%;
    padding: 10px;
    border: 1px solid #ddd;
    border-radius: 4px;
    box-sizing: border-box;
}

.btn {
    display: inline-block;
    padding: 10px 15px;
    border: none;
    border-radius: 4px;
    cursor: pointer;
    font-size: 16px;
    text-align: center;
    text-decoration: none;
    margin-right: 10px; /* ボタン間のスペース */
    margin-bottom: 10px; /* ボタン間のスペース */
}

.btn:hover {
    opacity: 0.9;
}

/* Button Colors */
.btn-primary {
    background-color: #007bff;
    color: white;
}
.btn-info {
    background-color: #17a2b8;
    color: white;
}
.btn-success {
    background-color: #28a745;
    color: white;
}
.btn-warning {
    background-color: #ffc107;
    color: #212529;
}
.btn-danger {
    background-color: #dc3545;
    color: white;
}
.btn-secondary {
    background-color: #6c757d;
    color: white;
}
.btn-light {
    background-color: #f8f9fa;
    color: #212529;
    border: 1px solid #ced4da;
}

.message {
    padding: 10px;
    margin-bottom: 15px;
    border-radius: 4px;
}

.message.success {
    background-color: #d4edda;
    color: #155724;
    border: 1px solid #c3e6cb;
}

.message.error {
    background-color: #f8d7da;
    color: #721c24;
    border: 1px solid #f5c6cb;
}

.balance {
    font-size: 1.2em;
    font-weight: bold;
    margin-top: 20px;
    margin-bottom: 20px;
}

.logout-form {
    margin-top: 20px;
    margin-bottom: 30px;
}

.section-group {
    border: 1px solid #e0e0e0;
    border-radius: 8px;
    padding: 15px;
    margin-bottom: 20px;
    background-color: #fdfdfd;
}

.section-group h3 {
    margin-top: 0;
    margin-bottom: 15px;
    color: #007bff;
    border-bottom: 1px solid #eee;
    padding-bottom: 10px;
}

/* 既存のadmin-linkスタイルは不要になるため削除 */
/* .admin-link { margin-top: 20px; display: block; } */