このページのviewportは【device-width, user-scalable=no, initial-scale=1, maximum-scale=1】です。

リンク

• iPhone用…<meta name="viewport" content="width=320, user-scalable=no, initial-scale=1, maximum-scale=1">
• Android用…<meta name="viewport" content="width=width=device-width, user-scalable=no, initial-scale=1, maximum-scale=1">