.gc_wrapper {
      max-width: 800px;
      min-width: 200px;
      margin: 2.0833% auto;
    }

    .responsive-iframe-container {
        position: relative;
        padding-bottom: 56.25%;
        padding-top: 30px;
        height: 0;
        overflow: hidden;
    }
    .responsive-iframe-container iframe,
    .responsive-iframe-container object,
    .responsive-iframe-container embed {
        position: absolute;
        top: 0;
        left: 0;
        width: 100%;
        height: 100%;
    }

    @media (max-width: 600px) {
        .big-container {
            display: none;
        }
        .small-container {
           padding-bottom: 200%;   /* 高さ */
        }
    }
    @media (min-width: 600px) {
        .small-container {
            display: none;
        }
    }