Darken Image on Hover

Hi fellow Squarespace users,

I,d like to get help on setting up a hover effect to this gallery block here on my homepage: https://www.neynarhm.com - What I intend to do upon hovering is either:
1.  the image can be darker
2. the image can turn into grayscale, like this one here (but no need to be moved up): https://www.victorberbel.work 

No 2 is the ideal one, but no  1 only is fine.
Anybody knows what I should do on the CSS setup?

Thanks for the help!

10 hours ago, Ziggy said:

Try adding this custom CSS:

section[data-section-id="63774c57fe920e0a4eed4475"] {
   .sqs-block-image .design-layout-fluid img {
     transition:ease-in-out 300ms;
     &:hover {
       filter: grayscale(100%);
     }
   }
}

Let me know if that helps, give me a thumbs up if it does.

It works! Thanks Ziggy!