body {
    /* --- 背景画像と全体の基本設定 --- */
    background-image: url('emma.jpg');
    background-size: cover;
    background-position: center top;
    background-repeat: no-repeat;
    font-family: "Helvetica Neue", Arial, "Hiragino Kaku Gothic ProN", "Hiragino Sans", Meiryo, sans-serif;
    color: #333;
    margin: 0;
    /* 画面の高さを100%に固定し、スクロールさせない設計にする */
    height: 100vh;
    height: 100dvh; /* iOSの動くアドレスバー対策の最新規格 */
    position: relative;
    box-sizing: border-box;
    overflow: hidden;
}

.mobile-container {
    /* --- 絶対配置（absolute）で絶対に画面一番下にアンカーさせる --- */
    position: absolute;
    bottom: 0;
    left: 0;
    width: 100%;
    max-width: 100%;
    background-color: rgba(255, 255, 255, 0.95);
    backdrop-filter: blur(10px);
    -webkit-backdrop-filter: blur(10px);
    border-radius: 24px 24px 0 0;
    /* 下部の余白をしっかり多めにとって、ホームバーやブラウザのバーに隠れないように調整 */
    padding: 25px 20px calc(25px + env(safe-area-inset-bottom)) 20px;
    box-shadow: 0 -10px 30px rgba(0, 0, 0, 0.4);
    box-sizing: border-box;
}

.portal-badge {
    display: block;
    font-size: 1.1rem;
    font-weight: bold;
    letter-spacing: 0.08em;
    color: #1a1a1a;
    margin-bottom: 4px;
}

.mobile-container h2 {
    margin-top: 0;
    font-size: 1.5rem;
    color: #1a1a1a;
    margin-bottom: 10px;
}

.mobile-container p {
    font-size: 0.95rem;
    color: #444;
    line-height: 1.4;
    margin-bottom: 20px;
}

.btn-launch {
    display: block;
    text-align: center;
    padding: 14px 20px;
    background-color: #0066cc;
    color: #fff;
    text-decoration: none;
    border-radius: 12px;
    font-weight: bold;
    font-size: 1.05rem;
    box-shadow: 0 4px 15px rgba(0, 102, 204, 0.4);
}

.btn-launch:active {
    background-color: #004d99;
}