* {
            margin: 0;
            padding: 0;
            box-sizing: border-box;
        }

        body {
            font-family: 'Helvetica Neue', Arial, 'Hiragino Kaku Gothic ProN', 'Hiragino Sans', Meiryo, sans-serif;
            background: #f5f5f5;
            padding: 0;
            line-height: 1.8;
            color: #333;
            margin: 0;
        }

        .container {
            max-width: 800px;
            margin: 0 auto;
            background: white;
            border-radius: 0;
            box-shadow: none;
            overflow: hidden;
            min-height: 100vh;
        }

        @media (min-width: 768px) {
            body {
                padding: 20px;
            }

            .container {
                border-radius: 2px;
                box-shadow: 0 2px 8px rgba(0, 0, 0, 0.08);
                min-height: auto;
            }
        }

        .header {
            background: #2c3e50;
            color: white;
            padding: 20px 16px;
            text-align: center;
            border-bottom: 1px solid #34495e;
        }

        .header h1 {
            font-size: 20px;
            font-weight: 600;
        }

        @media (min-width: 768px) {
            .header {
                padding: 30px;
            }

            .header h1 {
                font-size: 28px;
            }
        }

        .content {
            padding: 16px;
        }

        @media (min-width: 768px) {
            .content {
                padding: 40px 30px;
            }
        }

        .info-card {
            background: #fafafa;
            border-left: 3px solid #7f8c8d;
            padding: 16px;
            margin-bottom: 12px;
            border-radius: 0;
            transition: background 0.2s;
        }

        @media (min-width: 768px) {
            .info-card {
                padding: 20px;
                margin-bottom: 16px;
            }
        }

        .info-card:hover {
            background: #f5f5f5;
        }

        .info-card.highlight {
            background: #fff9f5;
            border-left-color: #c0392b;
        }

        .info-card.success {
            background: #f9fdf9;
            border-left-color: #27ae60;
        }

        .info-title {
            font-size: 15px;
            font-weight: 600;
            color: #2c3e50;
            margin-bottom: 10px;
            display: flex;
            align-items: center;
        }

        @media (min-width: 768px) {
            .info-title {
                font-size: 16px;
                margin-bottom: 12px;
            }
        }

        .info-card.highlight .info-title {
            color: #c0392b;
        }

        .info-card.success .info-title {
            color: #27ae60;
        }

        .icon {
            display: inline-block;
            width: 20px;
            height: 20px;
            margin-right: 8px;
            flex-shrink: 0;
        }

        @media (min-width: 768px) {
            .icon {
                width: 24px;
                height: 24px;
            }
        }

        .link {
            color: #34495e;
            text-decoration: none;
            font-weight: 600;
            border-bottom: 1px solid #95a5a6;
            transition: border-color 0.2s, color 0.2s;
        }

        .link:hover {
            color: #2c3e50;
            border-bottom-color: #2c3e50;
        }

        .email {
            background: #34495e;
            color: white;
            padding: 10px 16px;
            border-radius: 0;
            display: inline-block;
            margin-top: 8px;
            font-weight: 500;
            text-decoration: none;
            transition: background 0.2s;
            font-size: 13px;
            word-break: break-all;
        }

        .email:hover {
            background: #2c3e50;
        }

        @media (min-width: 768px) {
            .email {
                padding: 10px 18px;
                font-size: 14px;
            }
        }

        .note {
            background: #fffbf0;
            border: 1px solid #e0d5b7;
            padding: 10px 12px;
            border-radius: 0;
            margin-top: 10px;
            font-size: 13px;
            color: #7f6f3e;
            line-height: 1.6;
        }

        @media (min-width: 768px) {
            .note {
                padding: 12px 16px;
                margin-top: 12px;
                font-size: 14px;
            }
        }

        p {
            font-size: 14px;
            margin: 0 0 8px 0;
        }

        @media (min-width: 768px) {
            p {
                font-size: 15px;
            }
        }

        @media (max-width: 600px) {
            .container {
                border-radius: 0;
            }

            .content {
                padding: 24px 20px;
            }

            .header h1 {
                font-size: 24px;
            }
        }