Gallery Block hover css

Site URL: https://www.no9gardens.ca/eco-art-exhibition

How do I target the new in-line GALLERY BLOCK? I believe it's only available for Circle Members.
I just want a simple hover effect over each image, something like opacity: .8

thanks in advance.

I think I answered my own question. Is it this?

.sqs-gallery-block-grid.sqs-gallery-thumbnails-per-row-3 .sqs-gallery-design-grid-slide:hover
{opacity: .8;}

You can also use this code

.gallery-block .slide:hover {
    opacity: 0.8;
}

Perfect thank you!