userChrome.css

@namespace html url("http://www.w3.org/1999/xhtml");
:root {
  --surface-800: #e4e4e7;
  --input-600: #f4f4f5;
  --tabsurface-500: #f4f4f5;
  --lwt-selected-tab-background-color: var(--tabsurface-500) !important;
  --uc-tabs-width: 40vw;
  --uc-toolbar-height: 34px;
  --uc-font-family: "JetBrains Mono", monospace;
  --uc-bg-color: var(--surface-800);
  --toolbarbutton-border-radius: 0px;
  --tab-min-height: 24px;
}
/* hide macos buttons */
.titlebar-buttonbox-container {
  display: none;
}
.titlebar-spacer {
  width: 12px !important;
}
.tab-text,
.tab-label {
  font-family: var(--uc-font-family) !important;
  font-size: 12px !important;
}
#alltabs-button {
  display: none;
}
.titlebar-placeholder:not([type="pre-tabs"]) {
  display: none;
}
#navigator-toolbox:first-child() {
  margin-left: 10px;
}
#TabsToolbar #firefox-view-button[open] > .toolbarbutton-icon,
#tabbrowser-tabs:not([noshadowfortests])
  .tab-background:is([selected], [multiselected]) {
  box-shadow: 0 0 4px rgba(0, 0, 0, 0.2) !important;
}
#TabsToolbar,
#nav-bar {
  height: var(--uc-toolbar-height) !important;
  background-color: var(--uc-bg-color) !important;
}
#nav-bar {
  font-family: var(--uc-font-family) !important;
}
#TabsToolbar {
  margin-left: var(--uc-tabs-width);
}
#nav-bar {
  margin-right: calc(100vw - var(--uc-tabs-width));
  margin-right: 0;
  margin-top: calc(var(--uc-toolbar-height) * -1);
  width: var(--uc-tabs-width) !important;
}
/* hide tab toolbar when fullscreen */
#nav-bar[inFullscreen],
#TabsToolbar[inFullscreen] {
  display: none;
}
/* hide titlebar buttons */
#TabsToolbar > .titlebar-buttonbox-container {
  display: none !important;
}
#urlbar {
  box-shadow: none !important;
  --urlbar-height: var(--uc-toolbar-height) !important;
}
#urlbar[breakout][breakout-extend] {
  width: 100% !important;
  top: calc(
    (var(--urlbar-toolbar-height) - var(--urlbar-height)) / 2
  ) !important;
  left: 0 !important;
}
#urlbar[breakout][breakout-extend] > #urlbar-input-container {
  height: var(--urlbar-height) !important;
  padding-block: unset !important;
  padding-inline: 1px !important;
}
#urlbar,
#searchbar {
  min-height: unset !important;
}
#urlbar-input-container {
  background: var(--input-600) !important;
  order: 2;
}
#urlbar > .urlbarView {
  order: 1;
}
/* BUTTONS */
.toolbarbutton-icon,
.toolbarbutton-animatable-icon,
#nav-bar-customization-target
  :where(#reload-button, #stop-button)
  > .toolbarbutton-icon {
  height: 24px !important;
  width: 24px !important;
  padding: 4px !important;
}
/* Space around urlbar */
#customizableui-special-spring1,
#customizableui-special-spring2 {
  display: none;
}
/* Urlbar */
#urlbar-background {
  display: none;
}
#urlbar-input-container,
#searchbar {
  border-radius: 0 !important;
}
toolbar .toolbarbutton-1 > .toolbarbutton-badge-stack {
  padding: 0 !important;
}

/* Tabs */
.tab-stack {
  padding-top: 1px !important;
}
.tab-background,
.tab-stack {
  height: 27px !important;
  min-height: unset !important;
}
.toolbar-items
  #tabbrowser-tabs[haspinnedtabs]:not([positionpinnedtabs])
  > #tabbrowser-arrowscrollbox
  > .tabbrowser-tab[first-visible-unpinned-tab] {
  margin-inline-start: 2px !important;
}
.titlebar-spacer[type="pre-tabs"],
.titlebar-spacer[type="post-tabs"] {
  width: 32px;
}
#tabs-newtab-button {
  padding-top: 2px !important;
}
.tab-close-button {
  width: 20px !important;
  height: 20px !important;
  padding: 4px !important;
}
/* Search popout */
#urlbar-background {
  display: none !important;
}
#urlbar[breakout][breakout-extend] > #urlbar-background {
  transform: translateY(34px) !important;
}

#urlbar[open] > .urlbarView > .urlbarView-body-outer > .urlbarView-body-inner,
.urlbarView:not([noresults]) > .search-one-offs:not([hidden]) {
  border-top: unset !important;
}
.urlbarView {
  margin: 0 !important;
  padding: 2px 10px !important;
  background-color: var(--input-600) !important;
  border: none !important;
  width: 100% !important;
}

@media screen and (max-width: 1280px) {
  #TabsToolbar {
    margin-top: 0 !important;
    margin-left: 0 !important;
    width: 100vw !important;
  }
  #nav-bar {
    margin-top: 0 !important;
    margin-right: 0 !important;
    width: 100vw !important;
  }
  .titlebar-spacer {
    width: 6px !important;
  }
  #urlbar-input-container,
  #searchbar,
  #urlbar-background,
  .urlbarView {
    border-radius: 6px !important;
  }
  #urlbar[breakout][breakout-extend] > #urlbar-input-container,
  #urlbar[breakout][breakout-extend] > #urlbar-background {
    border-radius: 6px !important;
  }
  .urlbarView {
    margin-top: 6px !important;
  }
  .tab-stack {
    padding-top: 4px !important;
  }
  #tabs-newtab-button {
    padding-top: 6px !important;
  }
  #urlbar {
    --urlbar-height: calc(var(--uc-toolbar-height) - 6px) !important;
  }
}