Removing shadows and boxes around linked images in galleries

Hi All,

I am using Ugallu child theme on the Stargazer framework.

I want to see if there’s a way to get rid of the ugly lightboxes on gallery images using CSS.

This only seems to effect linked images in a gallery, not individual images.

I have tried this code but it doesn’t make a difference:

a img {
border: none;
background: none;
}

My site is here (you can see the boxes around the pink buttons at the bottom of this page very clearly):

https://acatlikecuriosity.com/

If anyone could help with that I would be very grateful.

Many Thanks,

Sarah