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

        body {
            font-family: "メイリオ", Meiryo, "ＭＳ Ｐゴシック", "Hiragino Kaku Gothic Pro", sans-serif;
            font-size: 16px;
            line-height: 1.8;
            color: #222732;
            background: #f8f9fa;
        }

        .container {
            max-width: 1240px;
            margin: 0 auto;
            padding: 0 20px;
        }

        header {
            background: linear-gradient(135deg, #a7d2f4 0%, #85c3ec 100%);
            padding: 15px 0;
            box-shadow: 0 2px 10px rgba(0,0,0,0.1);
        }

        header .container {
            display: flex;
            justify-content: space-between;
            align-items: center;
        }

        header h1 {
            font-size: 20px;
            color: #fff;
            font-weight: bold;
            flex: 1;
        }

        nav {
            background: #fff;
            border-bottom: 3px solid #85c3ec;
            padding: 15px 0;
            margin-bottom: 30px;
        }

        nav ul {
            list-style: none;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 30px;
        }

        nav a {
            color: #222732;
            text-decoration: none;
            font-weight: 500;
            padding: 8px 15px;
            border-radius: 5px;
            transition: all 0.3s ease;
        }

        nav a:hover {
            background: #85c3ec;
            color: #fff;
        }

        main {
            background: #fff;
            padding: 50px 0;
        }

        article {
            max-width: 900px;
            margin: 0 auto 50px;
            padding: 0 20px;
        }

        article h1 {
            font-size: 36px;
            color: #050505;
            margin-bottom: 30px;
            text-align: center;
            line-height: 1.3;
            font-weight: bold;
        }

        article h2 {
            font-size: 30px;
            color: #3398db;
            margin: 40px 0 20px;
            padding-bottom: 10px;
            border-bottom: 3px solid #85c3ec;
            font-weight: bold;
        }

        article h3 {
            font-size: 24px;
            color: #222732;
            margin: 30px 0 15px;
            font-weight: bold;
        }

        article h4 {
            font-size: 20px;
            color: #3398db;
            margin: 25px 0 15px;
            font-weight: bold;
        }

        article h5 {
            font-size: 18px;
            color: #222732;
            margin: 20px 0 10px;
            font-weight: bold;
        }

        article h6 {
            font-size: 16px;
            color: #222732;
            margin: 15px 0 10px;
            font-weight: bold;
        }

        article p {
            margin-bottom: 20px;
            color: #222732;
        }

        .transition-section {
            background: linear-gradient(to bottom, #fff 0%, #f0f8ff 100%);
            padding: 40px 20px;
            margin: 40px 0;
        }

        .transition-section .container {
            max-width: 900px;
        }

        .links-section {
            background: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAoAAAAKCAYAAACNMs+9AAAAGElEQVQYlWNgYGD4z0AEYBxVSF+FDAwAAKQDAf/9/+0AAAAASUVORK5CYII=') repeat;
            padding: 60px 20px;
            margin-top: 40px;
        }

        .links-section .container {
            max-width: 1200px;
        }

        .links-section h3 {
            font-size: 28px;
            color: #050505;
            margin-bottom: 25px;
            font-weight: bold;
            text-align: center;
        }

        .links-section ul {
            list-style: none;
            display: grid;
            grid-template-columns: repeat(2, 1fr);
            gap: 15px 30px;
            margin-bottom: 40px;
        }

        .links-section li {
            background: url('data:image/png;base64,iVBORw0KGgoAAAANSUhEUgAAAAwAAAAMCAYAAABWdVznAAAARUlEQVQoU2NkYGD4z0AimBhIBKMKRxWOKhxVSKpCRhINj6o4VTiqcFThqEJSFTKSaHhUxaniUYWjCkcVkqqQkUTDowoBAKDYAw1NZ1CrAAAAAElFTkSuQmCC') no-repeat left 5px;
            padding-left: 20px;
        }

        .links-section a {
            color: #222732;
            text-decoration: underline;
            transition: all 0.3s ease;
            display: inline-block;
            padding: 5px 0;
        }

        .links-section a:hover {
            color: #3398db;
            text-decoration: none;
        }

        footer {
            background: #fff;
            border-top: 20px solid #85c3ec;
            padding: 40px 0 20px;
        }

        footer .footer-content {
            display: grid;
            grid-template-columns: repeat(auto-fit, minmax(250px, 1fr));
            gap: 30px;
            margin-bottom: 30px;
        }

        footer .footer-bottom {
            background: #daedf9;
            padding: 20px;
            text-align: center;
            font-size: 13px;
            color: #222732;
            margin-top: 30px;
        }

        @media (max-width: 768px) {
            header h1 {
                font-size: 16px;
            }

            nav ul {
                flex-direction: column;
                gap: 10px;
                align-items: center;
            }

            article h1 {
                font-size: 28px;
            }

            article h2 {
                font-size: 24px;
            }

            article h3 {
                font-size: 20px;
            }

            article h4 {
                font-size: 18px;
            }

            .links-section ul {
                grid-template-columns: 1fr;
                gap: 10px;
            }

            .links-section h3 {
                font-size: 22px;
            }

            footer .footer-content {
                grid-template-columns: 1fr;
            }
        }

        @media (max-width: 480px) {
            body {
                font-size: 14px;
            }

            header h1 {
                font-size: 14px;
            }

            article h1 {
                font-size: 24px;
            }

            article h2 {
                font-size: 20px;
            }

            .links-section {
                padding: 40px 15px;
            }
        }