.wrapper {
    margin: 0 auto;
    width: 80%;
    text-align: center;
}

.image-gallery {
    margin: 0 auto;
    display: table;
    position: sticky;
    top: 0;
}

.primary,
.thumbnails {
    display: table-cell;
}

.thumbnails {
    width: 300px;
}

.primary {
    width: 100vh;
    height: 400px;
    background-color: transparent;
    background-size: contain;
    background-position: center center;
    background-repeat: no-repeat;
    border-radius: 10px;
}

.thumbnail:hover .thumbnail-image, .selected .thumbnail-image {
    border: 4px solid red;
}

.thumbnail-image {
    width: 100px;
    height: 100px;
    margin: 2px;
    background-size: cover;
    background-position: center center;
    background-repeat: no-repeat;
    border-radius: 10px;
}