Delete featured image

Hi
I am using WP Show Posts and I chose the Generate Press theme (free) as I really like it’s simple clear design.
I want to delete the featured image in the article itself.
However, I would like to keep the featured image on my thumbnails look on the home page.
I have managed to delete all the images in the simple post through CSS

.single-post .page-header-image-single {
display: none;
}

but I can’t delete the features images in the pages.
Thoughts?

The page I need help with: [log in to see the link]