gecko-dev/browser/themes/shared/sidebar.inc.css

%if 0
/* 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/. */
%endif

#sidebar-box {
  --sidebar-background-color: -moz-Field;
  --sidebar-text-color: -moz-FieldText;
  background-color: var(--sidebar-background-color);
  color: var(--sidebar-text-color);
  text-shadow: none;
}

#sidebar-header {
  font-size: 1.333em;
  padding: 8px;
  border-bottom: 1px solid var(--sidebar-border-color);
}

%ifndef MOZ_WIDGET_GTK
% We don't let the splitter overlap the sidebar on Linux since the sidebar's
% scrollbar is too narrow on Linux.
.sidebar-splitter {
  -moz-appearance: none;
  border: 0 solid;
  border-inline-end-width: 1px;
  border-color: var(--sidebar-border-color);
  min-width: 1px;
  width: 4px;
  background-image: none !important;
  background-color: transparent;
  margin-inline-start: -4px;
  position: relative;
}

#sidebar-box[positionend] + .sidebar-splitter {
  border-inline-end-width: 0;
  border-inline-start-width: 1px;
  margin-inline-start: 0;
  margin-inline-end: -4px;
}
%endif

#sidebar-throbber[loading="true"] {
  list-style-image: url("chrome://global/skin/icons/loading.png");
}

@media (min-resolution: 2dppx) {
  #sidebar-throbber[loading="true"] {
    list-style-image: url("chrome://global/skin/icons/loading@2x.png");
    width: 16px;
  }
}

#sidebar-title {
  margin: 0;
  padding: 0;
  padding-inline-start: 8px;
  padding-inline-end: 4px;
}

#sidebar-switcher-arrow {
  -moz-context-properties: fill;
  fill: currentColor;
  opacity: 0.8;
}

#sidebar-switcher-arrow {
  list-style-image: url(chrome://global/skin/icons/arrow-dropdown-12.svg);
  width: 12px;
  height: 12px;
}

#sidebar-switcher-target {
  -moz-appearance: none;
  color: inherit;
  margin-inline-end: 4px;
  border-radius: var(--toolbarbutton-border-radius);
  border: 1px solid transparent;
  padding: 2px 4px;
}

#sidebar-switcher-target:hover {
  background: var(--toolbarbutton-hover-background);
}

#sidebar-switcher-target:hover:active,
#sidebar-switcher-target.active {
  background: var(--toolbarbutton-active-background);
}

/* Ensure we do not lose contrast between lightweight and OS theme colours */
#sidebar-switcher-target:hover:-moz-lwtheme {
  background: hsla(240, 5%, 5%, 0.1);
}
#sidebar-switcher-target:hover:active:-moz-lwtheme,
#sidebar-switcher-target.active:-moz-lwtheme {
  background: hsla(240, 5%, 5%, 0.15);
}

#sidebarMenu-popup .subviewbutton {
  min-width: 190px;
}

toolbarseparator + #sidebar-extensions-separator {
  display: none;
}

#sidebarMenu-popup > .subviewbutton[checked="true"] {
  list-style-image: none;
  background: url(chrome://global/skin/icons/check.svg) no-repeat transparent;
  background-size: 11px 11px;
}

%ifdef XP_MACOSX

#sidebarMenu-popup > .subviewbutton[checked="true"] {
  background-position: top 7px left 4px;
}

#sidebarMenu-popup > .subviewbutton[checked="true"]:-moz-locale-dir(rtl) {
  background-position: top 7px right 4px;
}

%else

#sidebarMenu-popup > .subviewbutton[checked="true"] {
  background-position: center left 7px;
}

#sidebarMenu-popup > .subviewbutton[checked="true"]:-moz-locale-dir(rtl) {
  background-position: center right 7px;
}

/* Allow room for the checkbox drawn as a background image at the start of the toolbarbutton */
#sidebarMenu-popup > .subviewbutton-iconic > .toolbarbutton-icon {
  margin-inline-start: 16px;
}
/* Align items without icons to the start of the icons: */
#sidebarMenu-popup > .subviewbutton:not(.subviewbutton-iconic) > .toolbarbutton-text {
  padding-inline-start: 16px;
}

%endif

#sidebar-switcher-bookmarks > .toolbarbutton-icon,
#sidebar-box[sidebarcommand="viewBookmarksSidebar"] > #sidebar-header > #sidebar-switcher-target > #sidebar-icon {
  list-style-image: url(chrome://browser/skin/bookmark.svg);
  -moz-context-properties: fill;
  fill: currentColor;
  opacity: 0.8;
}

#sidebar-switcher-history > .toolbarbutton-icon,
#sidebar-box[sidebarcommand="viewHistorySidebar"] > #sidebar-header > #sidebar-switcher-target > #sidebar-icon {
  list-style-image: url(chrome://browser/skin/history.svg);
  -moz-context-properties: fill;
  fill: currentColor;
  opacity: 0.8;
}

#sidebar-switcher-tabs > .toolbarbutton-icon,
#sidebar-box[sidebarcommand="viewTabsSidebar"] > #sidebar-header > #sidebar-switcher-target > #sidebar-icon {
  list-style-image: url(chrome://browser/skin/tab.svg);
  -moz-context-properties: fill;
  fill: currentColor;
  opacity: 0.8;
}