div.prv_modal { /* modal window */
    display: none;
    position: fixed;
    z-index: 999;
    left: 0;
    top: 0;
    width: 100%;
    height: 100%;
    overflow: auto;
    background-color: rgb(0,0,0);
    background-color: rgba(0,0,0,0.7);
    text-align: center;
    padding: 8px;
}

div.prv_modal iframe.prv_modal_content { /* video in modal window */
    margin: auto;
    width: 640px;
    height: 480px;
    border: 1px solid #eee;
}

/* modal window controls */

div.prv_modal div.prv_modal_prev,
div.prv_modal div.prv_modal_next,
div.prv_modal div.prv_modal_close {
    position: absolute;
    font-size: 1.0em;
    font-weight: bold;
    padding: 14px;
    background-color: #666;
    background-color: #d2955f;
    border-radius: 15%;
    color: white;
    cursor: pointer;
}

div.prv_modal div.prv_modal_prev {
    top: 50%;
    left: 40px;
}

div.prv_modal div.prv_modal_next {
    top: 50%;
    right: 40px;
}

div.prv_modal div.prv_modal_close {
    top: 32px;
    right: 40px;

}

/* hover background color */
div.prv_modal div.prv_modal_prev:hover,
div.prv_modal div.prv_modal_next:hover,
div.prv_modal div.prv_modal_close:hover {
    background-color: #888;
}










div.prv_main { /* main image/video container */
    width: 100%;
/*
    height: 300px;
    width: 300px;
*/
    cursor: zoom-in;
}

div.prv_main iframe.prv_main_content { /* video */
    width: 350px;
    height: 263px;
/*
    width: 300px;
    height: 225px;

    width: 100%;

original video size
    width: 480px;
    height: 360px;
*/
}










ul.prv_thumb { /* thumbnail container */
    width: 100%;
/*
    width: 300px;
*/
    list-style-type: none;
    margin: 0;
    margin-top: 0.3em;
    padding: 0;
    border: 1px green solid;
    border: none;
}


@media screen and (max-width: 768px) {
    ul.prv_thumb { /* thumbnail container */
        overflow: auto;
        white-space: nowrap;
        width: 100%;
/*
        width: 300px;
*/
        height: 80px;
    }


    div.prv_modal div.prv_modal_prev {
        top: 80%;
        left: 40px;
    }

    div.prv_modal div.prv_modal_next {
        top: 80%;
        right: 40px;
    }

}


ul.prv_thumb li.prv_thumb_element { /* thumnail element */
    margin: 0.3em;
    padding: 0;
    display: inline-block;
    position: relative;
    cursor: pointer;
    width: 50px;
    height: 50px;
    border: 1px #444444 solid;
    border: none;
}


div.prv_main img.prv_main_content,  /* main image */
div.prv_modal img.prv_modal_content, /* image in modal window */
ul.prv_thumb li.prv_thumb_element img.prv_thumb_content /* image thumnail */
{
    margin: 0;
    padding: 0;
    width: 100%;
    height: 100%;
    object-fit: contain;
    border: 1px #aaaaaa solid;
    border: none;
}

div.prv_modal img.prv_modal_content {
    margin: auto;
    max-width: 720px;
border: 1px solid #eee;
border: none;
}

ul.prv_thumb li.prv_thumb_element img.prv_play { /* play button on thumbnail video */
    position: absolute;
    width: 24px;
    top: 50%;
    left: 50%;
    transform: translate(-50%, -50%);
    border: none;
}