gecko/browser/themes/shared/aboutWelcomeBack.css

/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

.title {
  background-image: url("chrome://browser/skin/welcome-back.svg");
}

.radioRestoreContainer:not(:last-child) {
  margin-bottom: 0.2em;
}

/* tablist starts out hidden, but JS may make it visible in response to
   clicks on the radio buttons by setting an "available" attribute.
*/
.tree-container:not([available]) {
  display: none;
}

treechildren::-moz-tree-image(icon),
treechildren::-moz-tree-image(noicon) {
  padding-right: 2px;
  margin: 0 2px;
  width: 16px;
  height: 16px;
}

treechildren::-moz-tree-image(noicon) {
  list-style-image: url("chrome://mozapps/skin/places/defaultFavicon.png");
}
treechildren::-moz-tree-image(container, noicon) {
  list-style-image: url("chrome://browser/skin/aboutSessionRestore-window-icon.png");
}

treechildren::-moz-tree-image(checked) {
  list-style-image: url("chrome://global/skin/in-content/check.svg#check");
}
treechildren::-moz-tree-image(checked, selected) {
  list-style-image: url("chrome://global/skin/in-content/check.svg#check-inverted");
}

treechildren::-moz-tree-image(partial) {
  list-style-image: url("chrome://global/skin/in-content/check-partial.svg#check-partial");
}
treechildren::-moz-tree-image(partial, selected) {
  list-style-image: url("chrome://global/skin/in-content/check-partial.svg#check-partial-inverted");
}