.yt-hd-thumbnail-inner-container {
    height: 0;
    padding-top: 56.25%;
    position: relative;
}

    .yt-hd-thumbnail-inner-container > a.yt-hd-thumbnail, .yt-hd-thumbnail-inner-container > iframe {
        display: block;
        position: absolute;
        top: 0;
        left: 0;
        right: 0;
        bottom: 0;
        border-width: 0;
    }

    .yt-hd-thumbnail-inner-container > a.yt-hd-thumbnail {
        z-index: 2;
    }

        .yt-hd-thumbnail-inner-container > a.yt-hd-thumbnail img {
            max-width: 100%;
        }

        .yt-hd-thumbnail-inner-container > a.yt-hd-thumbnail.yt-hd-thumbnail-darken:before {
            display: block;
            position: absolute;
            content: '';
            top: 0;
            left: 0;
            right: 0;
            bottom: 0;
            background-color: #000;
            opacity: .3;
            -webkit-transition: opacity .3s ease;
            -moz-transition: opacity .3s ease;
            transition: opacity .3s ease;
        }

        .yt-hd-thumbnail-inner-container > a.yt-hd-thumbnail.yt-hd-thumbnail-darken:hover:before {
            opacity: 0;
        }

        .yt-hd-thumbnail-inner-container > a.yt-hd-thumbnail:after {
            display: block;
            position: absolute;
            content: '';
            background-image: url(youtube-play.svg);
            background-size: contain;
            background-repeat: no-repeat;
            background-position: center center;
            width: 80px;
            height: 80px;
            top: 50%;
            left: 50%;
            margin-left: -40px;
            margin-top: -40px;
            opacity: .5;
            -webkit-transition: opacity .3s ease;
            -moz-transition: opacity .3s ease;
            transition: opacity .3s ease;
        }

        .yt-hd-thumbnail-inner-container > a.yt-hd-thumbnail:hover:after {
            opacity: .8;
        }

    .yt-hd-thumbnail-inner-container > iframe {
        max-width: 100%;
        opacity: 0;
        -webkit-transition: opacity .3s ease .3s;
        -moz-transition: opacity .3s ease .3s;
        transition: opacity .3s ease .3s;
    }

    .yt-hd-thumbnail-inner-container.yt-hd-thumbnail-clicked > a.yt-hd-thumbnail {
        display: none;
    }

    .yt-hd-thumbnail-inner-container.yt-hd-thumbnail-clicked > iframe {
        opacity: 1;
    }