Transparent Background/ BG opacity and removing gallery arrows

Im trying to make the bg when clicking on single images transparent or lower the opacity to half.
The author says find the .pswp__bg and edit the opacity from 0 to 1 as a set example being 0.7.
I did find that and set the opacity to 0.5 as a test and nothing is happening. Tried editing and saving post again just to make sure it will work and change the code but nothing.

Would appreciate any help i can get with that.

Also, if anyone knows how to remove the previous and next arrows that appear when you have more than 2 images set to be clicked, it turns them into a sort of gallery and you can hit next by using the arrows and go through all images on the page. I would like to remove that feature as i want the images to just have the animation of zoom in and zoom out that Photoswipe offers without it turning my whole page into a gallery.

Im not the most knowledgeable with codes so if anyone could just point me to the area i need to change and tell me how i have to change it that would be awesome!

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