Iconic Firefox — userChrome CSS snippet which adds back icons for context and popup menus in Firefox. It uses only built-in icons for optimal performance and design consistency.

iconic_firefox.css

/* Iconic Firefox (https://gist.github.com/emvaized/a379d61ed8970e5711ca7278a39c1895/) */
/* Author (c) 2025 emvaized */
/* Based on https://gist.github.com/qaz69wsx/83a90423163b65a8344b2e60fc356a58 (no longer available) */
/* For better compatibility with dark mode, enable `svg.context-properties.content.enabled` in `about:config` */

:root{
    --uc-popup-menu-icon-color: color-mix(in srgb, currentColor 75%, transparent);
}
.subviewbutton:not(.subviewbutton-iconic, [checked="true"], [targetURI])>.toolbarbutton-icon,
.subviewbutton:not(.subviewbutton-iconic, [checked="true"], [targetURI])>.protections-popup-footer-icon,
menuitem[data-l10n-id="text-action-redo"]:before{
	width:16px;
	height:16px;
	margin-inline-end:8px !important;
	-moz-context-properties:fill, fill-opacity;
	fill:var(--uc-popup-menu-icon-color);
}
menupopup:not(.in-menulist)>menu:not(.menu-iconic),
menupopup:not(.in-menulist, [aria-label])>menuitem:not(.menuitem-iconic, [type="radio"], [type="checkbox"]),
toolbarbutton[data-l10n-id*="-manage-"],
menuitem[data-l10n-id*="-manage-"],
#downloadsHistory,
#appMenu-zoom-controls{
	padding-inline-start:calc(1em + 24px) !important;
	background-position:left 1em center;
	background-repeat:no-repeat;
	background-size:16px;
	-moz-context-properties:fill, fill-opacity;
	fill:var(--uc-popup-menu-icon-color) !important;
}
#fxa-manage-account-button>vbox>label{
	margin-inline-start:24px !important;
}
.PanelUI-remotetabs-notabsforclient-label{
	margin-inline-start:40px !important;
}
.widget-overflow-list .toolbarbutton-1:not(.toolbarbutton-combined)>.toolbarbutton-text,
toolbarbutton[data-l10n-id*="-manage-"]{
	padding-inline-start:8px !important;
}
#appMenu-fxa-label2::before,
#fxa-manage-account-button::after{
	content:"";
	display:-moz-box;
	border-radius:50%;
	background:var(--avatar-image-url) no-repeat center/contain;
	-moz-context-properties:fill, fill-opacity;
	fill:var(--uc-popup-menu-icon-color);
}
#appMenu-fxa-label2::before{
	width:16px;
	height:16px;
	margin-inline-end:8px;
}
#fxa-manage-account-button::after{
	width:32px;
	height:32px;
}
.syncNowBtn{
	visibility:visible !important;
	-moz-box-ordinal-group:0 !important;
	margin-inline-end:8px;
    order:0 !important;
}
menupopup[needsgutter] {
    @media (-moz-platform: linux) or (-moz-platform: windows) {
        > :is(menu, menuitem):not([image], [checked="true"], [type="checkbox"], [type="radio"]) > .menu-icon {
            display: none !important;
        }
    }
}
#PanelUI-fxa-menu-setup-sync-button{
	list-style-image:url("chrome://browser/skin/sync.svg");
}
.subviewbutton[data-l10n-id$="-settings"]:not([data-l10n-id*="-manage-"]){
	list-style-image:url("chrome://global/skin/icons/settings.svg");
}
.subviewbutton[data-l10n-id="fxa-menu-connect-another-device"]{
	list-style-image:url("chrome://global/skin/icons/plus.svg");
}
#appMenu-new-tab-button2{
	list-style-image:url("chrome://browser/skin/new-tab.svg");
}
#appMenu-new-window-button2,
#appMenuRecentlyClosedWindows{
	list-style-image:url("chrome://browser/skin/window.svg");
}
#appMenu-new-private-window-button2{
	list-style-image:url("chrome://browser/skin/privateBrowsing.svg");
}
.subviewbutton[data-l10n-id="library-bookmarks-menu"],
#panelMenuBookmarkThisPage[starred],
#sidebar-switcher-bookmarks{
	list-style-image:url("chrome://browser/skin/bookmark-hollow.svg");
}
#panelMenuBookmarkThisPage{
	list-style-image:url("chrome://browser/skin/bookmark-hollow.svg");
}
#panelMenu_searchBookmarks,
#appMenu-find-button2,
#appMenuSearchHistory,
#allTabsMenu-searchTabs{
	list-style-image:url("chrome://global/skin/icons/search-glass.svg");
}
#panelMenu_viewBookmarksToolbar{
	list-style-image:url("chrome://browser/skin/bookmark-star-on-tray.svg");
}
.subviewbutton[id$="-history-button"],
#sidebar-switcher-history{
	list-style-image:url("chrome://browser/skin/history.svg");
}
#appMenuRecentlyClosedTabs{
	list-style-image:url("chrome://browser/skin/tabs.svg");
}
#appMenuClearRecentHistory,
toolbarbutton.restoreallitem{
	list-style-image:url("chrome://browser/skin/forget.svg");
}
.subviewbutton[id$="-downloads-button"]{
	list-style-image:url("chrome://browser/skin/downloads/downloads.svg");
}
#appMenu-passwords-button{
	list-style-image:url("chrome://browser/skin/login.svg");
}
#appMenu-extensions-themes-button{
	list-style-image:url("chrome://mozapps/skin/extensions/extension.svg");
}
#appMenu-print-button2{
	list-style-image:url("chrome://global/skin/icons/print.svg");
}
#appMenu-save-file-button2{
	list-style-image:url("chrome://browser/skin/downloads/downloads.svg");
}
.subviewbutton[command="cmd_CustomizeToolbars"]{
	list-style-image:url("chrome://browser/skin/customize.svg");
}
.subviewbutton[oncommand="switchToTabHavingURI('about:performance', true)"]{
	list-style-image:url("chrome://global/skin/icons/performance.svg");
}
.subviewbutton[key="key_browserToolbox"]{
	list-style-image:url("chrome://devtools/skin/images/tool-inspector.svg");
}
.subviewbutton[key="key_aboutProcesses"]{
	list-style-image:url("chrome://devtools/skin/images/tool-profiler.svg");
}
.subviewbutton[key="key_aboutProcesses"] + .subviewbutton{
	list-style-image:url("chrome://global/skin/icons/developer.svg");
}
.subviewbutton[key="key_browserConsole"]{
	list-style-image:url("chrome://devtools/skin/images/tool-webconsole.svg");
}
.subviewbutton[key="key_toggleToolbox"]{
	list-style-image:url("resource://devtools-shared-images/command-pick.svg");
}
.subviewbutton[key="key_viewSource"]{
	list-style-image:url("chrome://devtools/skin/images/tool-styleeditor.svg");
}
.subviewbutton[key="key_responsiveDesignMode"]:not([checked="true"]){
	list-style-image:url("chrome://devtools/skin/images/command-responsivemode.svg");
	fill-opacity:0;
}
.subviewbutton[key="key_responsiveDesignMode"]+.subviewbutton{
	list-style-image:url("chrome://devtools/skin/images/command-eyedropper.svg");
}
.subviewbutton[data-l10n-id="appmenu-developer-tools-extensions"]{
	list-style-image:url("chrome://activity-stream/content/data/content/assets/glyph-webextension-16.svg");
}
#appMenu-help-button2,
#appMenu_menu_openHelp
{
	list-style-image:url("chrome://global/skin/icons/help.svg");
}
#appMenu_menu_HelpPopup_reportPhishingtoolmenu{
	list-style-image:url("chrome://global/skin/icons/warning.svg");
}
#appMenu_feedbackPage{
	list-style-image:url("chrome://global/skin/icons/lightbulb.svg");
}
#appMenu_troubleShooting{
	list-style-image:url("chrome://devtools/skin/images/browsers/firefox.svg");
}
#appMenu_helpSafeMode{
	list-style-image:url("chrome://global/skin/icons/security.svg");
}
#appMenu_helpSwitchDevice {
	list-style-image:url("chrome://browser/skin/import.svg");
}
#appMenu_aboutName{
	list-style-image:url("chrome://global/skin/icons/info.svg");
}
#appMenu-quit-button2{
	list-style-image:url('chrome://browser/skin/sync-off.svg');
}
#sidebar-switcher-tabs{
	list-style-image:url("chrome://browser/skin/tab.svg");
}
#sidebar-reverse-position[label="Move Sidebar to Right"]{
	list-style-image:url("chrome://browser/skin/sidebars-right.svg");
}
#sidebar-reverse-position[label="Move Sidebar to Left"]{
	list-style-image:url("chrome://browser/skin/sidebars.svg");
}
.subviewbutton[data-l10n-id="sidebar-menu-close"]{
	list-style-image:url("chrome://global/skin/icons/close.svg");
}
#BMB_bookmarksPopup menuitem:not(.menuitem-iconic),
#PlacesToolbar .openintabs-menuitem{
	padding-inline-start:32px !important;
	background-position-x:8px;
}
#menu_newNavigatorTab,
menuitem[id$="openANewTab"]{
	background-image:url("chrome://browser/skin/new-tab.svg");
}
#menu_newNavigator,
#historyUndoWindowMenu,
#context_openTabInWindow,
menuitem[data-l10n-id*="-open-"][data-l10n-id$="-window"]{
	background-image:url("chrome://browser/skin/window.svg");
}
menuitem[data-l10n-id$="-private-window"]{
	background-image:url("chrome://browser/skin/privateBrowsing.svg") !important;
}
#menu_openFile{
	background-image:url("chrome://browser/skin/open.svg");
}
#menu_savePage,
#context-saveimage,
#context-savelink,
#context-saveframe,
#context-savevideo,
#context-savepage{
	background-image:url("chrome://browser/skin/downloads/downloads.svg");
}
menuitem[data-l10n-id$="-email"],
menuitem[data-l10n-id$="-email-link"]{
	background-image:url("chrome://browser/skin/mail.svg");
}
menuitem[data-l10n-id*="-print"]{
	background-image:url("chrome://global/skin/icons/print.svg");
}
#menu_importFromAnotherBrowser,
#browserImport{
	background-image:url("chrome://browser/skin/import.svg");
}
#menu_FileQuitItem{
	background-image:url('chrome://browser/skin/sync-off.svg');
}
menuitem[data-l10n-id="text-action-undo"],
menuitem[data-l10n-id$="-reopen-closed-tabs"]{
	background-image:url("chrome://global/skin/icons/undo.svg");
}
menuitem[data-l10n-id="text-action-redo"]:before{
	background-image:url("chrome://global/skin/icons/undo.svg");
	transform:scaleX(-1) !important;
	content: "";
	position: absolute;
	left: 16px;
}
menuitem[data-l10n-id="text-action-cut"]{
	background-image:url("chrome://browser/skin/edit-cut.svg");
}
menuitem[data-l10n-id="text-action-copy"],
#context-copyimage-contents,
#syncedTabsCopySelected{
	background-image:url("chrome://global/skin/icons/edit-copy.svg");
}
#context-stripOnShareLink,
menuitem[data-l10n-id="text-action-strip-on-share"]{
	background-image:url("chrome://browser/skin/fingerprint.svg");
}
menuitem[data-l10n-id="text-action-paste"]{
	background-image:url("chrome://browser/skin/edit-paste.svg");
}
menuitem[data-l10n-id="text-action-paste-no-formatting"]{
	background-image:url("chrome://browser/skin/edit-paste.svg");
}
menuitem[data-l10n-id="text-action-delete"],
#toolbar-context-remove-extension,
.downloadDeleteFileMenuItem,
menuitem[id^="placesContext_delete"],
#unified-extensions-context-menu-remove-extension,
#pageActionContextMenuRemoveExtension,
#context_moveTabToSavedGroup{
	background-image:url("chrome://global/skin/icons/delete.svg");
}
#menu_find,
#BMB_searchBookmarks,
#context-searchselect-private,
#context-searchselect,
#context-keywordfield,
#context-visual-search{
	background-image:url("chrome://global/skin/icons/search-glass.svg");
}
#toggle_PersonalToolbar,
#BMB_viewBookmarksToolbar{
	background-image:url("chrome://browser/skin/bookmarks-toolbar.svg");
}
#menu_customizeToolbars,
#toolbar-context-customize{
	background-image:url("chrome://browser/skin/customize.svg");
}
#viewSidebarMenuMenu,
#BMB_viewBookmarksSidebar{
	background-image:url("chrome://browser/skin/sidebars.svg");
}
#menu_bookmarksSidebar:not([checked="true"]),
menuitem[data-l10n-id="menu-bookmark-edit"]{
	background-image:url("chrome://browser/skin/bookmark.svg") !important;
}
#menu_historySidebar:not([checked="true"]){
	background-image:url("chrome://browser/skin/history.svg");
}
#menu_tabsSidebar:not([checked="true"]),
#sync-tabs-menuitem{
	background-image:url("chrome://browser/skin/tab.svg");
}
#menu_zoomEnlarge{
	background-image:url("chrome://browser/skin/add-circle-fill.svg");
}
#menu_zoomReduce{
	background-image:url("chrome://browser/skin/subtract-circle-fill.svg");
}
#repair-text-encoding{
	background-image:url("chrome://browser/skin/characterEncoding.svg");
}
#fullScreenItem:not([checked="true"]){
	background-image:url("chrome://browser/skin/fullscreen.svg");
}
#menu_readerModeItem{
	background-image:url("chrome://browser/skin/reader-mode.svg");
}
#sanitizeItem,
#placesContext_deleteHost,
menuitem[data-l10n-id="downloads-cmd-clear-list"]{
	background-image:url("chrome://browser/skin/forget.svg");
}
#historyUndoMenu{
	background-image:url("chrome://devtools/skin/images/debugging-tabs.svg");
}
menuitem[data-l10n-id*="bookmark-"]:not(.menuitem-iconic),
#context-bookmarkframe,
#placesContext_createBookmark{
	background-image:url("chrome://browser/skin/bookmark-hollow.svg");
}
#menu_openDownloads{
	background-image:url("chrome://browser/skin/downloads/downloads.svg");
}
#menu_openAddons{
	background-image:url("chrome://mozapps/skin/extensions/extension.svg");
}
#sync-setup{
	background-image:var(--avatar-image-url);
}
menuitem[data-l10n-id$="-sync-now"]{
	background-image:url("chrome://browser/skin/sync.svg");
}
#webDeveloperMenu{
	background-image:url("chrome://browser/skin/developer.svg");
}
#menu_taskManager{
	background-image:url("chrome://global/skin/icons/performance.svg");
}
#menu_browserToolbox{
	background-image:url("chrome://devtools/skin/images/fox-smiling.svg");
}
#menu_responsiveUI:not([checked="true"]){
	background-image:url("chrome://devtools/skin/images/command-responsivemode.svg");
	fill-opacity:0;
}
#menu_eyedropper{
	background-image:url("chrome://devtools/skin/images/command-eyedropper.svg");
}
#extensionsForDevelopers{
	background-image:url("chrome://activity-stream/content/data/content/assets/glyph-webextension-16.svg");
}
#menu_pageInfo,
#context-viewimageinfo,
#context-viewframeinfo{
	background-image:url("chrome://global/skin/icons/info.svg");
}
#menu_preferences,
#openSettingsMenuItem,
#toolbar-context-customize-sidebar{
	background-image:url("chrome://global/skin/icons/settings.svg");
}
#menu_HelpPopup_reportPhishingtoolmenu{
	background-image:url("chrome://global/skin/icons/lightbulb.svg");
}
#aboutName{
	background-image:url("chrome://devtools/skin/images/browsers/firefox.svg");
}
#context_reloadTab,
#context_reloadSelectedTabs,
#context-reloadframe{
	background-image:url("chrome://global/skin/icons/reload.svg");
}
menuitem[id^="context_toggleMute"]:not([soundplaying], [muted]),
menuitem[id^="context_toggleMute"][soundplaying]:not([muted]),
#context-media-mute{
	background-image:url("chrome://global/skin/media/audio-muted.svg");
}
menuitem[id^="context_toggleMute"][muted],
#context-media-unmute{
	background-image:url("chrome://global/skin/media/audio.svg");
}
menuitem[data-l10n-id^="pin-"],
.customize-context-moveToPanel{
	background-image:url("chrome://browser/skin/pin-12.svg");
}
menuitem[data-l10n-id^="unpin-"],
.customize-context-moveToToolbar{
	background-image:url("chrome://browser/skin/pin.svg");
}
menuitem.sendtab-target[clientType="desktop"]{
	background-image:url("chrome://browser/skin/device-desktop.svg");
}
menuitem.sendtab-target[clientType="phone"]{
	background-image:url("chrome://browser/skin/device-phone.svg");
}
menuitem.sendtab-target[clientType="tablet"]{
	background-image:url("chrome://browser/skin/device-tablet.svg");
}
menuitem.sendtab-target[clientType="tv"]{
	background-image:url("chrome://browser/skin/device-tv.svg");
}
menuitem.sendtab-target[clientType="vr"]{
	background-image:url("chrome://browser/skin/device-vr.svg");
}
menuitem[data-l10n-id="full-screen-exit"]{
	background-image:url("chrome://browser/skin/fullscreen-exit.svg");
}
#paste-and-go{
	background-image:url("chrome://browser/skin/forward.svg");
}
.customize-context-reportExtension{
	background-image:url("chrome://global/skin/icons/warning.svg");
}
.downloadShowMenuItem,
#placesContext_showInFolder,
[data-l10n-id="places-add-folder-contextmenu"]{
	background-image:url("chrome://global/skin/icons/folder.svg");
}
.openintabs-menuitem,
menuitem[id^="context-open"]:is([id$="intab"], [id$="incontainertab"]),
menuitem[data-l10n-id$="-view-new-tab"],
menuitem[data-l10n-id$="-open-in-tab"]{
	background-image:url("chrome://global/skin/icons/open-in-new.svg");
}
#context-pocket,
#context-savelinktopocket{
	background-image:url("chrome://global/skin/icons/pocket-outline.svg");
}
menuitem[data-l10n-id$="-screenshot"]{
	background-image:url("chrome://browser/skin/screenshot.svg");
}
menuitem[data-l10n-id*="-copy-"][data-l10n-id*="-link"]:not(.menuitem-iconic){
	background-image:url("chrome://global/skin/icons/link.svg");
}
#context-searchselect[label*="Google"]{
	background-image:url("chrome://activity-stream/content/data/content/tippytop/favicons/google-com.ico");
}
#context-searchselect[label*="Bing"]{
	background-image:url("chrome://activity-stream/content/data/content/tippytop/favicons/bing-com.ico");
}
#context-searchselect[label*="DuckDuckGo"]{
	background-image:url("chrome://activity-stream/content/data/content/tippytop/favicons/duckduckgo-com.ico");
}
#context-inspect-a11y{
	background-image:url("chrome://devtools/skin/images/tool-accessibility.svg");
}
#context-inspect{
	background-image:url("resource://devtools-shared-images/command-pick.svg");
}
#context-media-play{
	background-image:url("chrome://global/skin/media/play-fill.svg");
}
#context-media-pause,
#doNotDisturbMenuItem{
	background-image:url("chrome://global/skin/media/pause-fill.svg");
}
#context-video-fullscreen{
	background-image:url("chrome://browser/skin/fullscreen.svg");
}
#context-leave-dom-fullscreen{
	background-image:url("chrome://browser/skin/fullscreen-exit.svg");
}
#context-video-saveimage{
	background-image:url("chrome://browser/skin/screenshot.svg");
}
#disableForOriginMenuItem{
	background-image:url("chrome://browser/skin/notification-icons/desktop-notification-blocked.svg");
}
menuitem[data-l10n-id^="places-edit-"]{
	background-image:url("chrome://global/skin/icons/edit.svg");
}
#context-translate-selection{
	background-image:url("chrome://browser/skin/translations.svg");
}
#appMenu-translate-button,
#appmenu-abouttranslations-button{
	list-style-image:url("chrome://browser/skin/translations.svg");
}
#appMenu-more-button2,
#identity-popup-more-info{
	list-style-image:url("chrome://global/skin/icons/more.svg");
}
#context-viewsource,
#context-viewframesource,
#context-viewpartialsource-selection{
	background-image:url("chrome://devtools/skin/images/tool-styleeditor.svg");
}
#context-selectall,
menuitem[data-l10n-id="text-action-select-all"]{
	/* background-image:url("resource:///chrome/devtools/skin/images/highlight-selector.svg"); */
	background-image:url("chrome://global/skin/reader/align-left-20.svg");
}
#unified-extensions-context-menu-move-widget-up{
	background-image:url("chrome://global/skin/icons/arrow-up.svg");
}
#unified-extensions-context-menu-move-widget-down{
	background-image:url("chrome://global/skin/icons/arrow-down.svg");
}
.customize-context-manageExtension,
#unified-extensions-context-menu-manage-extension{
	background-image:url("chrome://global/skin/icons/settings.svg");
}
#unified-extensions-context-menu-report-extension{
	background-image:url("chrome://global/skin/icons/warning.svg");
}
#context-setDesktopBackground{
	background-image:url("chrome://browser/skin/canvas.svg");
}
#appMenu-zoom-controls{
	background-image:url("chrome://global/skin/media/fullscreenEnterButton.svg");
	margin-inline-start:4px !important;
}
menu#frame{
	background-image:url("chrome://browser/skin/window.svg");
}
#context_moveToStart,
#context_closeTabsToTheStart{
	background-image:url("chrome://global/skin/icons/arrow-left.svg");
}
#context_moveToEnd,
#context_closeTabsToTheEnd{
	background-image:url("chrome://global/skin/icons/arrow-right.svg");
}
#context-media-playbackrate{
	background-image:url("chrome://global/skin/icons/performance.svg");
}
#identity-popup-clear-sitedata-button{
	list-style-image:url("chrome://global/skin/icons/delete.svg");
}
#toolbar-context-remove-from-toolbar,
#customizationPanelItemContextMenuRemove,
.downloadRemoveFromHistoryMenuItem,
#context_closeTab,
#orgClose{
	background-image:url("chrome://global/skin/icons/close.svg");
}
#context-showonlythisframe,
#context-media-showcontrols,
#context-previewlink{
	background-image:url('chrome://global/skin/icons/eye.svg');
}
#context-media-hidecontrols{
	background-image:url('chrome://global/skin/icons/eye-slash.svg');
}
/* Needs a fix for checkbox items rendered incorrectly with styles applied
#context-video-pictureinpicture:not([checked="true"]){
	background-image:url("chrome://global/skin/media/picture-in-picture-open.svg");
	fill: var(--uc-popup-menu-icon-color) !important;
}
*/
#spell-dictionaries{
	background-image:url("chrome://devtools/skin/images/globe.svg");
}
#spell-add-dictionaries,
[data-l10n-id="places-add-bookmark"],
#context_moveTabToGroupNewGroup{
	background-image:url("chrome://global/skin/icons/plus.svg");
}
toolbarbutton[data-l10n-id*="-manage-"],
menuitem[data-l10n-id*="-manage-"],
#manage-saved-logins{
	background-image:url("chrome://browser/skin/menu.svg");
}
#context-sendpagetodevice-popup menuseparator + menuitem,
#context_sendTabToDevicePopupMenu menuseparator + menuitem,
#context-sendlinktodevice-popup menuseparator + menuitem{
	background-image:url("chrome://global/skin/icons/chevron.svg");
}
#downloadsHistory{
	background-image:url("chrome://browser/skin/downloads/downloads.svg");
}
.downloadOpenReferrerMenuItem{
	background-image:url("chrome://global/skin/icons/defaultFavicon.svg")
}
#protections-popup-settings-button{
	list-style-image:url("chrome://global/skin/icons/settings.svg");
}
#protections-popup-show-report-button{
	list-style-image:url("chrome://browser/skin/controlcenter/dashboard.svg");
}
toolbarbutton.restoreallitem > .toolbarbutton-icon{
	transform:scaleX(-1);
}
#appMenu-report-broken-site-button,
#protections-popup-report-broken-site-button{
	list-style-image:url("chrome://global/skin/icons/lightbulb.svg");
}
#context-ask-chat,
#context_askChat{
	background-image:url("chrome://global/skin/icons/highlights.svg");
}
#fill-login{
	background-image:url("chrome://browser/skin/login.svg");
}
menuitem[id="context-openlinkinsidebar"][label="Open Link in Second Sidebar"]{
	background-image:url("chrome://userscripts/content/second_sidebar/icons/sidebar-right.svg");
}
#allTabsMenu-closeDuplicateTabs{
	list-style-image:url('chrome://browser/content/firefoxview/view-recentlyclosed.svg');
}
[data-l10n-id="places-add-separator"] {
	background-image:url("chrome://global/skin/reader/content-width-20.svg");
}
#context-sendpagetodevice,
#context-sendlinktodevice,
#context_sendTabToDevice{
	background-image:url("chrome://browser/skin/synced-tabs.svg");
}
#context_moveTabToSplitView,
#context-openlinkinsplitview{
	background-image:url("chrome://browser/skin/split-view-left-16.svg");
}
menu.share-tab-url-item{
	background-image:url("chrome://browser/skin/share.svg");
}
#context_addNote,
#context_editNote{
	background-image:url("chrome://global/skin/icons/tab-notes.svg");
}
#context_moveTabOptions{
	background-image:url("chrome://browser/skin/taskbar-tabs-move-tab.svg");
}
#context_moveTabToGroup,
#context_moveTabToNewGroup{
	background-image:url("chrome://browser/skin/tabbrowser/tab-groups.svg");
}
#context_reopenInContainer,
#context-openlinkinusercontext-menu,
[data-l10n-id="places-open-in-container-tab"]{
	background-image:url("chrome://browser/skin/topsites.svg");
}
#context_duplicateTab,
#context_duplicateTabs{
	background-image:url("chrome://browser/skin/tabs.svg");
}
#context_selectAllTabs{
	background-image:url("chrome://global/skin/reader/align-right-20.svg");
}
#context_closeTabOptions{
	background-image:url("chrome://browser/content/firefoxview/view-recentlyclosed.svg");
}
/* Checkboxes */
menupopup:not([needsgutter]) > menuitem[type="checkbox"]:not([checked]){
	padding-inline-start:calc(1em + 24px) !important;
}
menuitem[type="radio"],
menuitem[type="checkbox"] {
	position: relative;
}
menuitem[type="checkbox"]:before,
menuitem[type="radio"]:before{
	content: ""; position: absolute;
	width: 16px; height: 16px;
	border: 1px solid color-mix(in srgb, var(--uc-popup-menu-icon-color) 50%, transparent);
	left: 10px; top: 6px;
	border-radius: 3px;
}

by commenting out lines 665 - 672

Perhaps I could just disable these lines on Mac OS using @media (-moz-platform: macos) before we come up with a better solution for checkboxes problem.

the following has changed in Firefox CSS

Could you please clarify, what do you mean that it was changed in Firefox CSS? These rules work fine for me in Firefox 152.0.3

You are correct. What I forgot was that ****-inline-end etc was designed for multiple languages especially those that read right to left, whilst just ****-end etc is mainly for English languages. My boo boo.

As for list-style-image: vs content: This content: targets the browser icon container which in your case relevant. I started a discussion here 1 year ago: https://www.reddit.com/r/FirefoxCSS/comments/1mfdq1y/firefox_css_property_liststyleimage_to_change_to/

cheers.

@ChasCB
I use list-style-image for popup menu items from the navbar (like .subviewbutton), and just assign images as background-image to regular context menu items. I experimented with content approach for context menus, but found that it has no advantages over the currently used approach.

Fair enough.

I spent the afternoon in the browser toolbox trying to solve the issue I raised 4 days ago. Using all sorts of esoteric code I found there and throwing in @media (-moz-platform: macos) etc still no go.

Mystery 🤔