drupal/modules/overlay/overlay-parent.css

/* $Id$ */

html.overlay-open,
html.overlay-open body {
  height: 100%;
  overflow: hidden;
}

#overlay-container,
.overlay-modal-background,
.overlay-element {
  height: 100%;
  left: 0;
  position: fixed;
  top: 0;
  width: 100%;
  z-index: 500;
}

.overlay-modal-background {
  /* Using a transparent png renders faster than using opacity */
  background: transparent url(images/background.png) repeat;
}

.overlay-element {
  background: transparent;
  left: -200%;
  z-index: 501;
}
.overlay-element.overlay-active {
  left: 0;
}

html.overlay-open .displace-top,
html.overlay-open .displace-bottom {
  z-index: 600;
}

/**
 * IE6 shows elements with position:fixed as position:static so replace
 * it with position:absolute;
 */
* html #overlay-container,
* html .overlay-modal-background,
* html .overlay-element
{
  position: absolute;
}