Remove white lines from wordpress site

the lines are likely to be caused by this background image:
https://jennyhutchens.com/gryte/wp-content/themes/paragrams/images/main-bg.gif

in style.css in:

.li_container {
	background-attachment: scroll;
	background-image: url(images/main-bg.gif);
	background-repeat: repeat-y;
	background-position: left top;
}

Thanks a lot. Removed the background-image and the lines disappeared ??