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

/*! Alters the webextension Brief
  IMPORTANT: change the Internal UUID */
@-moz-document url-prefix("moz-extension://brief@mozdev.org/") {
  #sidebar {
    background-color: var(--in-content-box-background)!important
  }
  #main-message,
  #view-list > tree-item > .title,
  #view-title-label,
  .content,
  .day-header,
  .headline-feed-name,
  .headline-title,
  .sidebar-button,
  tree-item > .title {
    color: var(--in-content-page-color)!important
  }
  #sidebar-top {
    border-bottom: 1px solid!important
  }
  .sidebar-button:hover {
    color: var(--in-content-link-color)!important
  }
  tree-folder.selected > tree-folder-header,
  tree-item.selected {
    border-color: var(--in-content-link-color)!important;
    background-color: var(--in-content-link-color)!important
  }
  #feed-view-header {
    background: var(--in-content-category-header-background)!important
  }
  #sidebar-splitter,
  #tag-list-splitter {
    border-left: 3px solid!important;
    border-right: 1px solid!important;
    border-right-color: var(--in-content-category-header-background)
  }
  #sidebar-splitter:hover,
  #tag-list-splitter:hover {
    border-right-color: var(--in-content-link-color)!important
  }
  .full-container-inner {
    background: 0 0!important
  }
  .headline-container:hover > .headline-header {
    background-color: var(--in-content-category-header-background)!important
  }
  tree-folder:not(.selected) > tree-folder-header:hover,
  tree-item:hover:not(.selected) {
    background-color: var(--in-content-page-background)!important;
    border-color: var(--in-content-category-header-background)!important
  }
  #view-list > tree-item.selected > .title,
  .unread-count,
  tree-item.selected > .title {
    color: var(--in-content-selected-text)!important
  }
}