Firefox userCrome

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

/*
Original layout by /u/Herkt https://www.reddit.com/r/FirefoxCSS/comments/7eazix/my_attempt_at_a_oneline_interface/
Use with compact density
*/

:root:-moz-lwtheme-brighttext {                                      /* minor color changes to the default dark theme */
  /*--color-overflow: #222;                                            /* >> button color */
  /*--chrome-background-color: #111 !important;                        /* tab strip background & inactive tabs */
  /*--chrome-secondary-background-color: #222 !important;              /* nav bar & active tab */
  /*--chrome-color: #ccc !important;                                   /* url & tab text, close tab & new tab buttons */
  /*background-color: #444 !important;                                 /* top border of out of focus window */
}

:root:-moz-lwtheme-darktext {                                        /* minor changes to the default light theme */
  /*--color-overflow: #ddd;                                            /* >> button color */
  /*--chrome-background-color: #ccc !important;                        /* tab strip background & inactive tabs */
}

:root {
  --tabs-border: transparent !important;                             /* active tab left & right borders - not working in 58?*/
  --toolbox-border-bottom-color: transparent !important;             /* 1px line under background tabs */
  --chrome-nav-bar-controls-border-color: transparent !important;    /* border around url bar */
}

/* Move Tab-bar beside Nav-bar */
#TabsToolbar {
  margin-bottom: 0px !important;                /* not needed anymore? */
  margin-top: 0px !important;                   /*  */
  margin-left: 35vw !important;
  margin-right: -34px !important;
  max-height: 32px !important;
}

#urlbar-container {
  min-width: 0px !important;
}

#nav-bar {
  margin-bottom: -1px !important;               /* remove navbar bottom 1px border */
  margin-top: -32px !important;
  margin-right: 65vw !important;
  border-top: none !important;
  min-width: 0px !important;
}

/* Remove padding above tabbar in compact mode */
#main-window[sizemode="normal"] > #titlebar {
  -moz-appearance: initial !important;
}


/* Back & Forward buttons */
#back-button > .toolbarbutton-icon,
#forward-button > .toolbarbutton-icon {
  transform: scale(0.9, 0.9) !important;
  margin-left: -2px !important;
  margin-right: -2px !important;
}

/* Move hamburger menu to the left */
#PanelUI-button,
#customization-panel-container,
#customization-panelWrapper .panel-arrow {
  -moz-box-ordinal-group: 0 !important;
  margin-right: -6px !important;
}

#appMenu-popup {
  margin-right: -258px !important;
}

#appMenu-popup .panel-arrow {
  margin-right: 248px !important;
}

/* More tools... button */
#nav-bar-overflow-button {
  transform: scale(0.9, 0.9) !important;
  fill: var(--color-overflow) !important;
}


/* Tabs */
.tabbrowser-tab {
  height: 32px !important;
}

/* Remove empty space before first tab
Delete this rule if you need a space to drag the window*/
#TabsToolbar .titlebar-placeholder[type="pre-tabs"]{
    display: none !important;
}

/* Remove border between tabs
Delete this rule if you want separators between background tabs */
.tabbrowser-tab::after, .tabbrowser-tab::before {
  border-left: none !important;
}

/* Border between background tabs */
.tabbrowser-tab::after, .tabbrowser-tab::before {
  /*color: grey !important; */
  opacity: .2 !important;
 }

/* New tab button color */
#new-tab-button, .tabs-newtab-button {
  fill: var(--chrome-color) !important;
  }

/* tab line - adjust color & size, default #0a84ff 2px */
.tab-line {
  background-color: #0a84ff !important;
  height: 0px !important;
  }


/* Hide various elements */
/* Menu */
#appMenu-fxa-container,                    /* Sign in to Sync */
#appMenu-fxa-container+toolbarseparator,
/* #appMenuRestoreLastSession, */
#appMenu-zoom-controls,
#appMenu-zoom-controls+toolbarseparator,
#appMenu-edit-controls,
#appMenu-edit-controls+toolbarseparator,
#appMenu-library-button,
#appMenu-customize-button,
#appMenu-customize-button+toolbarseparator,
#appMenu-open-file-button,
#appMenu-save-file-button,
#appMenu-find-button,
#appMenu-more-button,

/* URL Bar */
#pageActionButton,
#pocket-button-box,
ar-button,
.autocomplete-history-dropmarker,
#identity-icon-labels
{
    display: none !important;
}

/* Remove window buttons (Close, Minimize, Fullscreen) */
#titlebar {display: none !important;}