Making thumbnail backgrounds transparent using Cursor Hover layout

Site URL: https://jackshugruedesign.com/work

Hi, I was wondering if anyone had a solution for this issue I am having in regards to my Work page using the SUHAMA template. My Work page is a "Hover: Follow Cursor" layout, and so when you hover your cursor over a particular project, a thumbnail of the project appears. I am trying to achieve a more dynamic look with these thumbnails, having them be different shapes and sizes, yet each thumbnail as of now has a light grey box background that I would like to get rid of and replace with a transparent background.

I created my thumbnails using Adobe Illustrator, and exported each file with a transparent background as a PNG. Yet, when uploaded to Squarespace this transparency is replaced by the light grey box- which I think is the art-board or composition background that the work was created on, even though it was exported with a transparent background, as the sizes look to be the same. 

To be more precise, I was wondering if there was anyway to have the thumbnail image have a transparent background when you hover your cursor over the project name. 

Thanks!

Add to Home > design > Custom CSS

.portfolio-hover-bg-overlay {
    opacity: 0 !important;
}

Amazing! Thank you so much!!!!