#grid {
  /* Vertical grid lines */
  background:url(images/bg-grid-980.gif) repeat-y 0 0;

  /* Dimensions - same width as your grid with gutters */
  width:980px;

/* Grid (left-aligned) */
/*
  position:absolute;
  top:0;
  left:0;
*/

/* Grid (centered) */
  position:absolute;
  top:0;
  left:50%;
  margin-left:-490px;
}

/**
 * Horizontal grid lines, defined by your base line height
 *
 * Remember, the CSS properties that define the box model:
 * visible height = height + borders + margins + padding
 */
#grid .horiz {
  /* 24px line height */
  height:23px;
  border-bottom:1px solid #750c16;
  margin:0;
  padding:0;
}