button.preview {
    z-index: 5;
    background-color: transparent;
    border: none;
    padding: 0;
}

button.preview .overlay {
    position: absolute;
    width: 100%;
    height: 100%;
    top: 0;
    left: 0;
    background-color: rgba(0, 0, 0, 0.2);
    color: #fff;
}

button.preview .overlay span {
    position: absolute;
    bottom: 1rem;
    left: 1rem;
}