This is index.css inside of the css folder, so when you use ./resources it will assume resources is inside of this current directory which is css. You need to go up 1 folder with ".." then you would be inside of the resource folder, which your images are in, so "../whatever.jpg"
Note that this is only with background images, the html side was fine.
https://github.com/UAllen95/prj-rev-bwfs-dasmoto/blob/0f78381b9a1004b72096b3ef85dd3a8a9f39a323/arts_%26_crafts/resources/css/index.css#L9
This is index.css inside of the css folder, so when you use ./resources it will assume resources is inside of this current directory which is css. You need to go up 1 folder with ".." then you would be inside of the resource folder, which your images are in, so "../whatever.jpg"
Note that this is only with background images, the html side was fine.