#PageMain { margin-top: 0; }

#PageMain { 
 background-repeat: repeat !important;
 background-position-y: top !important;
 background-position-x: center !important;
 background: url(https://www.sefiles.net/images/library/site/graph-paper.svg) !important;
 background-size: 100px auto !important;
}

#PageMain,
#PageFooter {
 margin-top: 0;
}