Пред. След. Кнопка Адаптивная

$(document).ready(function () {
    // get all images loaded
    var images = $(".chair-class");
    // thumbnails containers
    var thumbnailContainer = $("#thumbnails");
    var iframe1 = $('#sketchfab-iframe-1')[0];
    var iframe2 = $('#sketchfab-iframe-2')[0];
    var player1 = $f(iframe1);
    var player2 = $f(iframe2);
    // generate thumbnail images
    generateThumbnails(images, thumbnailContainer);
    // listeners for controls arrows
    $(".prev-next-button").on("click", function () {
        player1.api('pause');
        player2.api('pause');
        // get the images
        var currentImageIndex = images.index($(".chair-class[data-active=true]"));
        var isPrevious = $(this).hasClass("previous");
        var nextIndex;
        if (isPrevious) {
            if (currentImageIndex === 0) {
                nextIndex = images.length - 1;
            }

            if (currentImageIndex > 0) {
                nextIndex = currentImageIndex - 1;
            }
        } else {
            if (currentImageIndex === images.length - 1) {
                nextIndex = 0;
            }

            if (currentImageIndex < images.length - 1) {
                nextIndex = currentImageIndex + 1;
            }
        }

        // remove any active class from images
        images.removeClass("active").attr('data-active', "false");
        // get the next active image and add active class to that next current image
        var $nextImage = $(images[nextIndex]);
        var iframeId = $nextImage.data('iframe');
        if (iframeId) {
            $(images[nextIndex]).attr('data-active', "true");
            $('.sketchfab-iframe').removeClass('active');
            $('#' + iframeId).addClass('active');
        } else {
            $(images[nextIndex]).addClass("active").attr('data-active', "true");
            $('.sketchfab-iframe').removeClass('active');
        }
    });

    $(".thumb").on("click", function (event) {
        event.preventDefault();
        var images = $(".chair-class");
        var indexSelected = $(this).data("img-index");
        var currentShown = images.index($(".chair-class[data-active=true]"));
        if (currentShown === indexSelected) return false;
        player1.api('pause');
        player2.api('pause');
        images.removeClass("active").attr('data-active', "false");
        var iframeId = $(this).data('iframe');
        if (iframeId) {
            $(images[indexSelected]).attr('data-active', "true");
            $('.sketchfab-iframe').removeClass('active');
            $('#' + iframeId).addClass('active');
        } else {
            images.removeClass("active");
            $(images[indexSelected]).addClass('active').attr('data-active', "true");;
            $('.sketchfab-iframe').removeClass('active');
        }
    });

    function generateThumbnails(images, container) {
        var ul = $("<ul>");
        images.each(function (index, element) {
            var currentThumb = $("<img>");
            var li = $("<li>");
            var src = $(this).attr("src");
            currentThumb.attr("src", src);
            currentThumb.attr("class", "thumb");
            currentThumb.data("img-index", index);
            var iframe = $(this).data('iframe');
            if (iframe) {
                currentThumb.data("iframe", iframe);
            }
            li.append(currentThumb);
            ul.append(li);
        });
        container.append(ul);
    }
});

 * {
    margin: 0;
    padding: 0;
}

body {
    margin: 0;
    padding: 0;
    font-size: 100%;
}

/* #green-room {
    background: #333 !important;
  } */

.slideshow-container {
    max-width: 1000px;
    position: relative;
    margin: auto;
}

#chair, .chair-class {
    position: absolute;
    width: 100%;
    height: auto;
    max-width: 600px;
    max-height: 400px;
    margin: 0 auto;
    display: block;
    top: 0;
    left: 0;
    opacity: 0;
    transition: opacity .5s;
}

.chair-class.active {
    position: relative;
    opacity: 1;
}

#prev {
    position: absolute;
    color: black;
    left: 0;
    top: 0;
    bottom: 0;
}

#next {
    position: absolute;
    color: black;
    right: 0;
    top: 0;
    bottom: 0;
}

#prev p, #next p {
    font-size: 3em;
}

#imgDetail {
    position: relative;
    width: 90%;
    margin: 0 auto;
    overflow: hidden;
}

#imgDetail a {
    text-decoration: none;
    display: flex;
    padding: 3%;
    justify-content: center;
    align-items: center;
}

#imgDetail a:hover {
    background-color: #333;
    color: white;
    opacity: 0.5;
}

#imgDetail ul {
    margin: 0 auto;
    display: block;
}

#thumbnails {
    max-width: 1000px;
    width: 100%;
    display: inline-block;
    text-align: center;
}

.thumb {
    width: 21%;
    height: auto;
    margin-top: 15px;
    cursor: pointer;
}

#imgDetail li {
    display: inline;
}

#thumbnails ul {
    margin: 0 auto;
    display: block;
}

#thumbnails li {
    display: inline;
    padding-right: 2%;
}

#thumbnails li:last-child {
    padding-right: 0;
}

.sketchfab-iframe {
    position: absolute;
    top: 0;
    right: 0;
    bottom: 0;
    left: 0;
}

.sketchfab-iframe {
    opacity: 0;
    margin: 0 auto;
    transition: opacity .5s;
    display: none;
}

.sketchfab-iframe.active {
    opacity: 1;
    position: relative;
    display: block;
}

<script src = "https://f.vimeocdn.com/js/froogaloop2.min.js"></script>
<script src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js"></script>
<!-- Images not Owned by Me -->

<!DOCTYPE html>
<html lang = "en">
<head>
    <meta charset = "UTF-8">
    <meta name = "viewport" content = "width=device-width,initial-scale=1.0">
    <meta http-equiv = "X-UA-Compatible" content = "ie=edge">
    <title>Daniel Pollack</title>
    <link rel = "stylesheet" type = "text/css" href = "css/styles.css"/>
    <script src = "https://unpkg.com/scrollreveal/dist/scrollreveal.min.js">     </script>
    <script src = "https://ajax.googleapis.com/ajax/libs/jquery/2.1.1/jquery.min.js">       </script>
    <script src = "http://a.vimeocdn.com/js/froogaloop2.min.js"></script>
  <script src = "https://cdnjs.cloudflare.com/ajax/libs/fitvids/1.2.0/jquery.fitvids.js">
  </script>
  </head>

  <body id = "green-room">

    <div class = "slideshow-container">
        <div id = "imgDetail">
            <img data-iframe = "sketchfab-iframe-1" src = "https://i.vimeocdn.com/video/682901345_640.webp" class = "chair-class" data-active = "true" />
            <img data-iframe = "sketchfab-iframe-2" src = "https://i.vimeocdn.com/video/682890362_640.webp" class = "chair-class" data-active = "false" />
            <img src = "http://www.davidwightman.net/_images_landscape/Behemot/Behemot_detail_3.jpg" class = "chair-class" data-active = "false" />

            <div class = "aspect-ratio">
                <iframe id = "sketchfab-iframe-1" class = "sketchfab-iframe active" src = "https://player.vimeo.com/video/255482396" width = "100%" height = "400" frameborder = "0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
            </div>

            <div class = "aspect-ratio">
                <iframe id = "sketchfab-iframe-2" class = "sketchfab-iframe" src = "https://player.vimeo.com/video/255473875" width = "100%" height = "400" frameborder = "0" webkitallowfullscreen mozallowfullscreen allowfullscreen></iframe>
            </div>

            <!--CONTROLS-->
            <a href = "javascript:void(0)" id = "prev" class = "prev-next-button previous">
                <p>&#10092;</p>
            </a>
            <a href = "javascript:void(0)" id = "next" class = "prev-next-button next">
                <p>&#10093;</p>
            </a>
        </div>

        <!--Thumbnails-->
        <div id = "thumbnails">
        </div>


</html>