ShadowFox/css/userContent-files/webextension-tweaks/tree_style_tab.css

/*! Alters the webextension Tree Style Tab
  IMPORTANT: change the Internal UUID in BOTH locations */
@-moz-document url-prefix("moz-extension://tree_style_tab_UUID/resources/group-tab.html") {
  :root {
    background: var(--tone-7)!important
  }
  h1::before {
    background: var(--tone-4)!important
  }
  #tabs img[src="https://assets-cdn.github.com/favicon.ico"] {
    filter: invert(55%)!important
  }
}
/*! Alters the webextension Tree Style Tab
  IMPORTANT: change the Internal UUID all BOTH locations */
@-moz-document url-prefix("moz-extension://tree_style_tab_UUID/") {
  /*! Use Plain Dark Appearance */
#debug-configs,
  p,
  ul {
    color: var(--tone-4)!important
  }
  h1,
  legend {
    color: var(--accent-1)!important
  }
  a {
    color: var(--accent-2)!important
  }
  #autoGroupNewTabsDelayOnNewWindow,
  #autoGroupNewTabsTimeout,
  #importedConfigsFromLegacy,
  #importedTreeStructureFromLegacy,
  #legacyConfigsNextMigrationVersion,
  #userStyleRules {
    -moz-appearance: none!important;
    background: var(--tone-6)!important;
    color: var(--tone-4)!important;
    border-color: var(--tone-5)!important
  }
  #contextual-identities-selector,
  #newtab-action-selector,
  #tabContextMenu,
  .extra.has-submenu ul {
    background: var(--tone-6)!important;
    border: none!important
  }
  .menu-ui-59858.menu-ui.menu li.separator {
    border-color: var(--in-content-box-border-color)!important
  }
  fieldset {
    border: 2px solid!important;
    border-color: var(--in-content-box-border-color)!important
  }
  :root {
    background-color: var(--in-content-page-background)!important
  }
  .tab {
    background: var(--in-content-page-background)!important;
    border-color: var(--in-content-category-header-background)!important
  }
  .tab .label {
    color: var(--in-content-page-color)!important
  }
  .tab:hover {
    background-color: var(--in-content-category-header-background)!important
  }
  .tab.active {
    background-color: var(--in-content-border-focus)!important
  }
  .tab.selected {
    background-color: var(--primary-accent-color-dark)!important
  }
  .tab.active .label,
  .tab.selected .label {
    color: #fff!important
  }
  .tab.active:hover {
    background-color: var(--in-content-primary-button-background)!important
  }
  .tab.discarded {
    opacity: .75!important
  }
  .tab.discarded .label {
    color: var(--in-content-box-border-color)!important
  }
  .tab.unread .label {
    font-style: italic!important
  }
  .tab:not(:hover) .closebox {
    display: none!important
  }
  .after-tabs button,
  .twisty {
    color: var(--in-content-page-color)!important
  }
  .simulate-svg-context-fill:root .newtab-button::before {
    background: var(--in-content-page-color)!important
  }
  .tab.active .twisty {
    color: #fff!important
  }
  .newtab-button {
    background-color: var(--tone-7)!important
  }
  .newtab-button:hover {
    background-color: var(--tone-8)!important
  }
  #all-tabs .tab:not(.active)[data-current-uri*="github.com"] .favicon {
    filter: invert(65%)!important
  }
  .simulate-svg-context-fill:root .tab.group-tab .favicon-default::before {
    filter: invert(45%)!important
  }
  #background,
  #background::after,
  #tabbar {
    background: var(--in-content-page-background)!important
  }
}