gecko-dev/browser/themes/windows/aboutSyncTabs.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/. */

#tabs-display,
#tabsList {
  background-color: transparent;
  -moz-appearance: none;
  margin: 0;
}

#tabsList {
  width: 100%;
}

#tabs-display {
  background: #fff url(chrome://browser/skin/sync-bg.png) repeat-x center -80px;
}

#headers {
  background: url(chrome://browser/skin/sync-32.png) no-repeat;
  margin-top: 4px;
  width: 45em;
  height: 32px;
  -moz-margin-start: 2em;
  -moz-margin-end: 2em;
}

#tabsListHeading {
  font-size: 140%;
  font-weight: bold;
  -moz-margin-start: 40px;
}

richlistitem {
  -moz-margin-end: 2em;
}

richlistitem[selected="true"],
richlistitem:focus {
  outline-style: none;
}

richlistitem[type="tab"] {
  min-height: 3em;
  border: #999999 1px solid !important;
  padding: 2px 5px;
  margin-bottom: 4px;
  -moz-margin-start: 4em;
  border-radius: 6px;
  background-color: menu;
  width: 44em;
  opacity: 0.9;
  box-shadow:
    inset rgba(255, 255, 255, 0.5) 0 1px 0px,
    inset rgba(0, 0, 0, 0.1) 0 -2px 0px,
    rgba(0, 0, 0, 0.1) 0px 1px 0px;
}

richlistitem[type="tab"][selected="true"] {
  background-color: -moz-MenuHover;
}

richlistitem[type="client"] {
  min-height: 2em;
  color: #000000;
  -moz-margin-start: 2em;
  margin-top: 2px;
  margin-bottom: 3px;
  width: 42em;
  border-radius: 6px;
  background-color: transparent;
  -moz-user-focus: ignore !important;
}
richlistitem.mobile[type="client"] {
  list-style-image: url("chrome://browser/skin/sync-mobileIcon.png");
}
richlistitem.desktop[type="client"] {
  list-style-image: url("chrome://browser/skin/sync-desktopIcon.png");
}

.title,
.clientName {
  color: #000000;
  font-size: 1.1em;
}

.title[selected="true"],
.url[selected="true"] {
  color: inherit;
}

.url {
  color: -moz-nativehyperlinktext;
  font-size: 0.95em;
}

.tabIcon {
  -moz-padding-start: 2px;
  padding-top: 2px;
}