userChrome.css

toolbar {
  background: transparent !important;
}
toolbar menupopup {
  --panel-background: rgba(30,30,30,.9) !important;
}

.urlbarView-row[selected]
{
  background-color: rgba(0,0,0,.7) !important;
}

#sidebar {
  max-width: none !important;
  min-width: 0px !important;
  box-shadow: 0px 0px 25px rgba(0,0,0,.25);
  position: relative;
}
#sidebar-box {
  max-width: none !important;
}
#sidebar-splitter {
  position: relative;
  z-index: 1;
}

.findbar-textbox {
  font-size: 13px !important;
}

#TabsToolbar-customization-target {
  padding-left: 10px;
}

#personal-toolbar-empty-description,
#PersonalToolbar .toolbarbutton-1,
toolbarbutton.bookmark-item:not(.subviewbutton) {
  /* margin: 2px 1px !important; */
  padding: var(--bookmark-block-padding) 2px !important;
}
toolbarbutton {
  background: none;
}

#main-window
{
    /* background: transparent !important; */
}

#TabsToolbar,
.table-widget-empty-text
{
    -moz-appearance: -moz-mac-vibrant-titlebar-light !important;
 }

#TabsToolbar:-moz-lwtheme-brighttext,
.table-widget-empty-text:-moz-lwtheme-brighttext
{
    -moz-appearance: -moz-mac-vibrant-titlebar-dark !important;
 }

.tabbrowser-tab[selected="true"] .tab-label:-moz-lwtheme-brighttext
{
    color:white !important;
}

.tabbrowser-tab .tab-label:-moz-lwtheme-brighttext
{
    color:rgba(255,255,255,0.7) !important;
}


.tabbrowser-tab[selected="true"] .tab-background:-moz-lwtheme-brighttext
{
    box-shadow: inset 0em -4em 0em var(--toolbar-bgcolor) !important;
}

#navigator-toolbox {
    background-color: transparent !important;
}

/* menubar + bookmarks */

:root #nav-bar,
#PersonalToolbar,
#titlebar
{
  background: #111;
 -moz-appearance: -moz-mac-vibrant-titlebar-dark !important;
 -moz-font-smoothing-background-color: -moz-mac-vibrant-titlebar-dark !important;
}

#TabsToolbar, #nav-bar, #PersonalToolbar {
  background: #111;
 -moz-appearance: -moz-mac-vibrancy-dark !important;
}

/* simplify tabs */

#titlebar #TabsToolbar {
	padding: 6px 0px 2px 6px !important;
	background: rgba(var(--accent-color), 1) !important;
}
.titlebar-spacer[type="pre-tabs"] {
	/* border: 0 !important; */
	display: none;
}

#tabbrowser-tabs:not([movingtab]) > .tabbrowser-tab[beforeselected-visible]::after, #tabbrowser-tabs[movingtab] > .tabbrowser-tab[visuallyselected]::before, .tabbrowser-tab[visuallyselected]::after {
    opacity: 0 !important;
}
.tab-line {
    height: 0px !important;
}

.tabbrowser-tab {
    /* margin-left: 15px !important; */
    /* margin-right: 4px !important; */
    font-size: 12px !important;
}
.tabbrowser-tab:not([visuallyselected="true"]), .tabbrowser-tab:-moz-lwtheme {

}

tab[selected="true"] .tab-content {

}
tab[selected="true"] .tab-background {

}

.tabbrowser-tab::after, .tabbrowser-tab::before {
    border-left: 0 !important;
    opacity: 0 !important;
}

.tab-close-button {
	transition: all 0.3s ease !important;
  border-radius: 30px !important;
  transform: translate(-3px,0px);
}
.tab-close-button:hover {
    fill-opacity: 0.2 !important;
}

.tabbrowser-tab > .tab-stack > .tab-background {
	border-radius: 50px !important;
}
.tabbrowser-tab > .tab-stack > .tab-background:not([selected="true"]) {
	transition: all 0.3s ease !important;
}
.tabbrowser-tab:hover > .tab-stack > .tab-background:not([selected="true"]) {
    border-color: #000 !important;
    border-color: rgba(0,0,0, 1) !important;
}

#TabsToolbar #firefox-view-button[open] > .toolbarbutton-icon,
.tab-background:is([selected], [multiselected]) {
  background-color: rgba(255,255,255,.1) !important;
}


/* urlbar */
#urlbar-background
{
    margin-top: 0px !important;
    margin-bottom: 0px !important;

    padding: 1px !important;

    background: #404040 !important;
    box-shadow: inset 0px 0px 1px 0px #e3e3e3 !important;
    border-radius: 30px !important;
    border-color: #1a1a1a !important;
}

#urlbar:-moz-lwtheme, #navigator-toolbox #searchbar:-moz-lwtheme
{
    color: #FFFFFF !important;
}

/* bookmarks */
.bookmark-item{
  border-radius: 30px !important;
  transform: translate(0,-1px);
}

.bookmark-item:hover{
  /* background-color: transparent !important; */
}



.bookmark-item > .toolbarbutton-icon
{

  display: flex !important;
  justify-content: center !important;

	border-radius: 100% !important;
	padding: 6px !important;
	height: 28px !important;
	width: 28px !important;
	color: #f9f9fb !important;
	background-color: rgba(80,80,80,0.1) !important;

  transition-property: background-color;
  transition-duration: 0.5s;

}

.bookmark-item:hover > .toolbarbutton-icon
{
	/* background-color: rgba(100,100,100,0.9) !important; */
	background-color: transparent !important;
}
.toolbarbutton-text:not([value=""]) {
  padding-right: .75rem !important;
}

.bookmark-item:active
{
	color: rgba(160,160,160,0.9) !important;
}

#tabs-newtab-button .toolbarbutton-icon {
  border-radius: 30px !important;

  transition-property: background-color;
  transition-duration: 0.5s;
}

#tabs-newtab-button:hover .toolbarbutton-icon {
  background-color: rgba(130,130,130,0.5) !important;
}

#tabs-newtab-button:active .toolbarbutton-icon {
  background-color:  rgba(180,180,180,0.7) !important;
  color: rgba(110,110,110,0.7) !important;
}

.toolbarbutton-badge-stack{
  border-radius: 30px !important;
}

#tracking-protection-icon-container{
  border-radius: 30px !important;
}

#identity-icon-box{
  border-radius: 30px !important;
}

#identity-permission-box{
  border-radius: 30px !important;
}

#star-button-box{
  border-radius: 30px !important;
}

#reload-button{
   border-radius: 30px !important;
}

#notification-popup-box{
  border-radius: 30px !important;
}

#back-button:hover{
  border-radius: 30px !important;
}

#forward-button:hover{
  border-radius: 30px !important;
}

#PlacesToolbar {
  padding-bottom: 2px;
}

#PlacesToolbarItems {
  /* display: flex !important;
  justify-content: center !important; */
}

tab[pending], #alltabs-popup menuitem[pending] {background-color:  rgba(80, 80, 80,0.3)  !important;}




/*
 * Compact findbar at the top of the window
 * @source https://github.com/Timvde/UserChrome-Tweaks/blob/72145b152c50341f64dcbb00d902b29fbc2a7a10/findbar/compact-findbar-on-top.css
 *
 * Contributor(s): Madis0
 */

 .browserContainer > findbar {
  order: -1 !important;
  -moz-box-ordinal-group: 0;
  border: 1px solid threedshadow !important;

  /* Hide the "border" at the top by removing the box-shadow and background-image */
  border-top: none !important;
  box-shadow: none !important;
  background-image: none !important;

  /* Uncomment to add a transition from the top */
  /*
  transition: 400ms !important;
  z-index: 0 !important;
  */
}

/* Margin from top when hidden (necessary for the transition to work) */
/*findbar[hidden]{ margin-top: -2em !important; }*/

/* Aligns the close button to the center */
.findbar-closebutton {
  margin-inline-start: 0.5em !important;
  vertical-align: middle !important;
  margin-bottom: 0.25em !important;
  height: inherit !important;
}



box#navigator-toolbox-background,
#titlebar {
  background: linear-gradient(0deg, rgb(30, 30, 30) 0%, rgb(70, 70, 70) 100%)
}
toolbar#nav-bar,
toolbar#PersonalToolbar {
  background: transparent !important;
  box-shadow: none !important;
}
#PersonalToolbar {
  padding-inline: 0 !important;
}

#personal-bookmarks,
#nav-bar-customization-target,
#PanelUI-button {
  background: rgb(40,40,40) !important;
}