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

#highlighter-container {
  pointer-events: none;
}

#highlighter-controls {
  position: absolute;
  top: 0;
  left: 0;
}

#highlighter-veil-container {
  overflow: hidden;
}

#highlighter-veil-container:not([dim]) > .highlighter-veil,
#highlighter-veil-container:not([dim]) > hbox > .highlighter-veil {
  visibility: hidden;
}

#highlighter-veil-container:not([disable-transitions]) > .highlighter-veil,
#highlighter-veil-container:not([disable-transitions]) > #highlighter-veil-middlebox,
#highlighter-veil-container:not([disable-transitions]) > #highlighter-veil-middlebox > .highlighter-veil,
#highlighter-veil-container:not([disable-transitions]) > #highlighter-veil-middlebox > #highlighter-veil-transparentbox {
  -moz-transition-property: width, height;
  -moz-transition-duration: 0.1s;
  -moz-transition-timing-function: linear;
}

#highlighter-veil-bottombox,
#highlighter-veil-rightbox {
  -moz-box-flex: 1;
}

#highlighter-veil-middlebox:-moz-locale-dir(rtl) {
  -moz-box-direction: reverse;
}

.inspector-breadcrumbs-button {
  direction: ltr;
}

/*
 * Node Infobar
 */

#highlighter-nodeinfobar-container {
  position: absolute;
  max-width: 95%;
}

#highlighter-nodeinfobar-container:not([disable-transitions]) {
  -moz-transition-property: top, left;
  -moz-transition-duration: 0.1s;
  -moz-transition-timing-function: linear;
}

#highlighter-nodeinfobar-text {
  overflow: hidden;
  white-space: nowrap;
  text-overflow: ellipsis;
  direction: ltr;
}

.highlighter-nodeinfobar-button > .toolbarbutton-text {
  display: none;
}

#highlighter-nodeinfobar-container:not([locked]):not(:hover) > #highlighter-nodeinfobar > .highlighter-nodeinfobar-button {
  visibility: hidden;
}

#highlighter-nodeinfobar-container[locked] > #highlighter-nodeinfobar,
#highlighter-nodeinfobar-container:not([locked]):hover > #highlighter-nodeinfobar {
  pointer-events: auto;
}

html|*#highlighter-nodeinfobar-id,
html|*#highlighter-nodeinfobar-classes,
html|*#highlighter-nodeinfobar-pseudo-classes,
html|*#highlighter-nodeinfobar-tagname {
  -moz-user-select: text;
  cursor: text;
}

.highlighter-nodeinfobar-arrow {
  display: none;
}

#highlighter-nodeinfobar-container[position="top"]:not([hide-arrow]) > #highlighter-nodeinfobar-arrow-bottom {
  display: block;
}

#highlighter-nodeinfobar-container[position="bottom"]:not([hide-arrow]) > #highlighter-nodeinfobar-arrow-top {
  display: block;
}

#highlighter-nodeinfobar-container[disabled] {
  visibility: hidden;
}

html|*#highlighter-nodeinfobar-tagname {
  text-transform: lowercase;
}

.devtools-toolbarbutton:not([label]) > .toolbarbutton-text {
  display: none;
}

#inspector-option-toolbarbutton > .toolbarbutton-menu-dropmarker {
  display: none;
}

#inspector-layoutview-container > iframe {
  /* header size */
  height: 22px;
}

#inspector-layoutview-container:not([disable-transitions]) > iframe {
  -moz-transition-property: height;
  -moz-transition-duration: 0.2s;
}

#inspector-layoutview-container > iframe[open] {
  /* header size + layout view size: 22px + 155px */
  height: 177px;
}