gecko-dev/browser/base/content/tabview/tabview.css

/* Platform-independent structural styling for 
 * <strike>Tab Candy</strike> Panorama
----------------------------------*/

html {
  overflow: hidden;
/*   image-rendering: -moz-crisp-edges; */
}

body {
  padding: 0px;
  margin: 0 auto;
}

#content {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
}

#bg {
  position: absolute;
  top: 0;
  left: 0;
  width: 100%;
  height: 100%;
  z-index: -999999;
}

/* Tabs
----------------------------------*/

.tab {
  position: absolute;
  overflow: visible !important;
}

.tab canvas,
.cached-thumb {
  width: 100%;
  height: 100%;
  position: absolute;
  top: 0px;
  left: 0px;
}

.thumb {
  position: relative;
  width: 100%;
  height: 100%;
}

.thumb-shadow {
  position: absolute;
}

.favicon {
  position: absolute;
}

.close {
  position: absolute;
  cursor: pointer;
}

.expander {
  position: absolute;
}

.tab-title {
  position: absolute;
}

.stacked .tab-title,
.stacked .thumb-shadow {
  display: none;
}

.stack-trayed .tab-title {
  display: block !important;
}

/* Tab: Zooming
----------------------------------*/

.front {
  z-index: 999999 !important;
  -moz-border-radius: 0 !important;
  -moz-box-shadow: none !important;
  -moz-transform: none !important;
  image-rendering: -moz-crisp-edges;
}

/* Other Items
----------------------------------*/

.groupItem,
.info-item {
  position: absolute;
}

/* Trenches
----------------------------------*/

.guideTrench, 
.visibleTrench, 
.activeVisibleTrench {
  position: absolute;
}

.guideTrench {
  z-index: -101;
}

.visibleTrench {
  z-index: -103;
}

.activeVisibleTrench {
  z-index: -102;
}

/* Other
----------------------------------*/

.newTabButton {
  position: absolute !important;
  z-index: 99999;
}

.title-shield {
  position: absolute;
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  z-index: 10;
}

.transparentBorder {
  border: 1px solid transparent !important;
}

.stackExpander {
  position: absolute;
}

.shield {
  left: 0;
  top: 0;
  width: 100%;
  height: 100%;
  position: absolute;
}

/* Resizable
----------------------------------*/
.resizer {
  position: absolute;
}

.iq-resizable-handle {
  position: absolute;
  z-index: 99999;
  display: block;
}

.iq-resizable-disabled .iq-resizable-handle, 
.iq-resizable-autohide .iq-resizable-handle {
  display: none;
}