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

        body {
            font-family: 'Inter', 'Noto Sans JP', sans-serif;
            background: linear-gradient(145deg, #f5f7fc 0%, #eef2f8 100%);
            min-height: 100vh;
            display: flex;
            align-items: center;
            justify-content: center;
            padding: 20px;
        }

        .page-container {
            max-width: 1200px;
            width: 100%;
            background: #ffffff;
            border-radius: 48px;
            box-shadow: 0 25px 45px -12px rgba(0, 0, 0, 0.2), 0 2px 8px rgba(0, 0, 0, 0.02);
            overflow: hidden;
        }

        .page {
            padding: 3rem 2rem;
            transition: opacity 0.4s ease;
        }

        .page.hidden-page {
            display: none;
        }

        /* ページ1: シンプル */
        .simple-card {
            text-align: center;
            max-width: 560px;
            margin: 2rem auto;
            background: #fff;
            border-radius: 40px;
            padding: 2.5rem 1.8rem;
            box-shadow: 0 15px 35px rgba(0, 0, 0, 0.05);
        }

        .jp-badge {
            display: inline-block;
            background: #b22234;
            color: white;
            font-weight: 600;
            font-size: 0.85rem;
            padding: 6px 14px;
            border-radius: 40px;
            margin-bottom: 1.8rem;
        }

        h1 {
            font-size: 2rem;
            font-weight: 700;
            color: #1e2a3e;
            margin-bottom: 0.5rem;
        }

        .sub-text {
            font-size: 0.95rem;
            color: #5b6e8c;
            margin-bottom: 2rem;
        }

        .btn-group {
            display: flex;
            gap: 1.2rem;
            justify-content: center;
            flex-wrap: wrap;
            margin-top: 1rem;
        }

        .btn {
            border: none;
            padding: 0.9rem 2.4rem;
            font-size: 1rem;
            font-weight: 600;
            border-radius: 60px;
            cursor: pointer;
            transition: transform 0.2s, box-shadow 0.2s;
            font-family: inherit;
        }

        .btn-primary {
            background: #1e466e;
            color: white;
        }

        .btn-primary:hover {
            background: #0f3554;
            transform: translateY(-2px);
        }

        .btn-secondary {
            background: #f0f3f8;
            color: #2c3e66;
            border: 1px solid #dce3ec;
        }

        .btn-secondary:hover {
            background: #e6ecf4;
            transform: translateY(-2px);
        }

        /* ページ2: 図文 + ボタン */
        .feature-section {
            display: flex;
            flex-wrap: wrap;
            align-items: center;
            gap: 2.5rem;
            margin-bottom: 1.5rem;
        }

        .feature-text {
            flex: 1.2;
        }

        .feature-image {
            flex: 0.9;
            text-align: center;
        }

        .teacher-label {
            background: #fef3e2;
            color: #b45f1b;
            display: inline-block;
            padding: 0.3rem 1rem;
            border-radius: 50px;
            font-weight: 600;
            font-size: 0.8rem;
            margin-bottom: 1rem;
        }

        .feature-text h2 {
            font-size: 1.9rem;
            font-weight: 700;
            color: #0a2942;
            margin: 0.5rem 0 1rem;
            line-height: 1.3;
        }

        .accent-red {
            color: #c62828;
        }

        .benefits-list {
            margin: 1.5rem 0;
            list-style: none;
        }

        .benefits-list li {
            margin-bottom: 0.85rem;
            display: flex;
            align-items: center;
            gap: 10px;
            font-weight: 500;
            color: #2c3e50;
        }

        .check-mark {
            background: #e8f0fe;
            width: 26px;
            height: 26px;
            border-radius: 30px;
            display: inline-flex;
            align-items: center;
            justify-content: center;
            font-weight: bold;
            color: #1e466e;
        }

        .img-card {
            background: linear-gradient(135deg, #f1f5f9 0%, #e4eaf1 100%);
            border-radius: 32px;
            padding: 1rem;
            box-shadow: 0 12px 24px rgba(0,0,0,0.05);
        }

        .img-card svg {
            max-width: 100%;
            height: auto;
            border-radius: 24px;
        }

        .btn-large {
            padding: 1rem 2.5rem;
            font-size: 1.1rem;
            background: #c62828;
            color: white;
            border: none;
            box-shadow: 0 8px 18px rgba(198,40,40,0.25);
            width: 100%;
            max-width: 300px;
            margin-top: 0.8rem;
        }

        .btn-large:hover {
            background: #b12121;
            transform: translateY(-3px);
        }

        .small-note {
            font-size: 0.75rem;
            color: #8b9ab0;
            text-align: center;
            margin-top: 1rem;
        }

        /* ページ3: iframe 埋め込み (簡素化) */
        .iframe-wrapper {
            width: 100%;
            min-height: 70vh;
            border-radius: 32px;
            overflow: hidden;
            box-shadow: 0 8px 24px rgba(0,0,0,0.08);
            background: #f8fafd;
        }

        .iframe-wrapper iframe {
            width: 100%;
            height: 100vh;
            border: none;
            display: block;
        }

        .final-footer {
            text-align: center;
            margin-top: 1.5rem;
            font-size: 0.75rem;
            color: #7e8c9e;
        }

        .back-btn {
            background: #eef2f8;
            border: none;
            padding: 0.6rem 1.4rem;
            border-radius: 40px;
            font-size: 0.8rem;
            cursor: pointer;
            margin-top: 1rem;
            font-weight: 500;
        }

        @media (max-width: 720px) {
            .page {
                padding: 1.5rem;
            }
            .feature-section {
                flex-direction: column;
            }
            .feature-text h2 {
                font-size: 1.5rem;
            }
        }

        @keyframes fadeUp {
            from {
                opacity: 0;
                transform: translateY(16px);
            }
            to {
                opacity: 1;
                transform: translateY(0);
            }
        }

        .page:not(.hidden-page) {
            animation: fadeUp 0.45s ease forwards;
        }
        .footer-links {
            margin-top: 15px;
            display: flex;
            justify-content: center;
            flex-wrap: wrap;
            gap: 15px;
        }
        .footer-link{
            font-size: 13px;
            color: #5b6e8c;
        }