Background image seems to repeat endless to the right

I've searched the forum about center and background styling topics, but to no avail (nothing for latest Atahualpa version anyway.)

My background image seems to stretch out to the right. (Please see attached images.) on my site allthingsriviera.com

I've added a background image (top left repeat) on a layout width of 1000, fluid 100% and layout max width at 1145.

What do I need to adjust to fix the post/page container in the center and avoid an eternally long (to the right) background? (On a mobile device, the post/page container is to the left and the background image continues to the right.)

I'm on updated WP and Atahualpa 3.7.13

Thanks for any help!