.pdf-preview-block img {
    max-width: 100%;
    min-width: 116px;
    height: auto;
    border: 1px solid #888;
    box-shadow: 2px 2px 2px rgba(0,0,0,0.3);
}

.pdf-preview-block-link {
    display: inline-block;
    min-width: 116px;
    margin: 0 auto;
    text-align: center;
}