@DownPW it’s possible, yes, but you may inadvertently end up targeting other elements using the same class which of course isn’t desired.
Can you provide a link in DM for me to review?
How we can add background image to nodeBB?
@cagatay depends where you want to apply it
@phenomlab as for the sudonix for example all grey area.
@cagatay You’d target the body
tag and use the below line of CSS
background: url(/assets/customcss/backgrounds/default/default.png) no-repeat center center fixed;
Obviously, you need to change the path to suit where your image is being stored.
More info around the background
property can be found here