CSS:Hover not working

Site URL: http://arcprojects.squarespace.com/about

Hello,

Password is "arc"

I've added css and hover states for images. The initial filter works but the :hover: unset; isn't.

Here is my code

[data-section-id="611eecf680daaa03e8f89f8a"] img{
  filter: grayscale(100%)
}

[data-section-id="611eecf680daaa03e8f89f8a"] img:hover{
  filter: unset !important;
}

Thanks

Use this code

[data-section-id="611eecf680daaa03e8f89f8a"] img{
  filter: grayscale(100%);
}
[data-section-id="611eecf680daaa03e8f89f8a"] .image-block:hover img {
    filter: grayscale(0);
}