Note

Note that auditd is included in the big list of packages previously installed; the main reason is that it will segregate all apparmor messages; otherwise, firefox tends to spam syslog if apparmor is set up.

Note

userChrome.css source

@namespace
url(http://www.mozilla.org/keymaster/gatekeeper/there.is.only.xul);


/* How to inspect the browser UI: https://firefox-source-docs.mozilla.org/devtools-user/browser_toolbox/index.html */

/* Hide lots of cruft on the bookmarks toolbar */

#BMB_bookmarksPopup menuseparator[builder="end"],
#BMB_bookmarksToolbar+menuseparator,
#BMB_bookmarksToolbar,
#BMB_unsortedBookmarks,
#alltabs-button,
#appmenu_bookmarksPopup menuseparator[builder="end"],
#appmenu_bookmarksToolbar+menuseparator,
#appmenu_bookmarksToolbar,
#appmenu_unsortedBookmarks,
#bookmarksMenuItemsSeparator,
#bookmarksMenuPopup menuseparator[builder="end"],
#bookmarksToolbarFolderMenu+menuseparator,
#bookmarksToolbarFolderMenu,
#menu_unsortedBookmarks,
#organizeBookmarksSeparator,
#subscribeToPageMenuitem,
.hide-if-empty-places-result {
    display:none!important;
}

:root[sizemode="normal"] #nav-bar{ --uc-window-drag-space-width: 20px }

#titlebar{ -moz-appearance: none !important; }
#TabsToolbar{ min-height: 0px !important }

#tabbrowser-tabs,
#tabbrowser-arrowscrollbox{ min-height: 0 !important; }

:root:not([customizing]) #tabs-newtab-button,
:root:not([customizing]) #TabsToolbar-customization-target > .toolbarbutton-1,
:root:not([customizing]) #TabsToolbar .titlebar-button{
  -moz-appearance: none !important;
  height: 0px;
  padding-top: 0px !important;
  padding-bottom: 0px !important;
  -moz-box-align: stretch;
  margin: 0 !important;
}

.accessibility-indicator,
.private-browsing-indicator{ 
  height: unset !important;
}
.accessibility-indicator > hbox{ padding-block: 0 !important }

.tabbrowser-tab{
  height: calc(var(--tab-min-height) + 2 * var(--tab-block-margin,0px));
}

.tabbrowser-tab[first-visible-tab="true"][last-visible-tab="true"]{
  visibility: collapse !important;
  /* These seem unnecessary, but they achieve compatibility with hide_tabs_with_one_tab.css */
  min-height: 0 !important;
  height: 0;
}



/* past attempts at hiding one-tab tabbar */
/* .titlebar-spacer[type="pre-tabs"], .titlebar-spacer[type="post-tabs"] { */
/*     visibility: collapse; */
/* } */

/* .tab-label-container { */
/*     height: auto ! important; */
/* } */


/* Source file https://github.com/MrOtherGuy/firefox-csshacks/tree/master/chrome/hide_tabs_with_one_tab.css made available under Mozilla Public License v. 2.0
See the above repository for updates as well as full license text. */

/* Makes tabs toolbar items zero-height initially and sets enlarge them to fill up space equal to tab-min-height set on tabs. Optionally use privatemode_indicator_as_menu_button.css to replace main menu icon with private browsing indicator while tabs are hidden. */

/* This style causes CSD window controls to disappear on linux, but you can kind of work around that by using window_control_fallback_for_custom_windows_theme.css */

/* Hide Tab bar with only one Tab - [110] https://support.mozilla.org/en-US/questions/1394300 */
#tabbrowser-tabs .tabbrowser-tab:only-of-type,
#tabbrowser-tabs .tabbrowser-tab:only-of-type + #tabbrowser-arrowscrollbox-periphery{
  display:none !important;
}
#tabbrowser-tabs, #tabbrowser-arrowscrollbox {min-height:0!important;}
/* #TabsToolbar:not(:hover) */ #alltabs-button {display:none !important;}



/* Button re-styling */
#tabs-newtab-button{ transform: scale(0.8); }
#tabs-newtab-button:hover{
  background-color: var(--toolbarbutton-hover-background);
  border-radius: var(--tab-border-radius);
}

#tabs-newtab-button > .toolbarbutton-icon{
  padding: 0 !important;
  transform: scale(0.5);
  background-color: transparent !important;
}
/* Fix window controls not being clickable */
:root[tabsintitlebar] #toolbar-menubar[autohide="true"][inactive]{
  transition: height 0ms steps(1) 80ms;
}
:where(#nav-bar){
  border-inline: var(--uc-window-drag-space-width,0) solid var(--toolbar-fgcolor);
}
@media (-moz-platform: linux){
  #TabsToolbar .titlebar-buttonbox{
    -moz-box-align: stretch !important;
  }
  #TabsToolbar > .titlebar-buttonbox-container > .titlebar-buttonbox > .titlebar-button{
    transform: scale(0.8);
    margin-inline: -3px !important;
  }
  #TabsToolbar .titlebar-button > .toolbarbutton-icon{ padding: 0 13px !important }
}

For more details on editing userChrome.css, see Browser Toolbox help. See also this answer.