Dark new tab for Firefox

userContent.css

/* Dark new tab */
@-moz-document url("about:newtab") {
  body {
    background-color: #2A2A2E !important;
  }
  .top-site-outer .title span {
    color: #F9F9FA !important;
  }
  .collapsible-section .section-title.grey-title,
  .collapsible-section .section-title span {
    color: #45A1FF !important;
    fill: #45A1FF !important;
  }
  .prefs-button button,
  .search-wrapper .search-button {
    fill: #45A1FF !important;
  }
  .prefs-button button:hover,
  .prefs-button button:focus {
    background-color: inherit !important;
  }
  .search-wrapper input {
    background-color: #202023 !important;
    color: #F9F9FA !important;
  }
  .contentSearchSuggestionTable .contentSearchSuggestionsContainer,
  .contentSearchSuggestionTable .contentSearchOneOffsTable,
  .contentSearchSuggestionTable .contentSearchHeader,
  .contentSearchSuggestionTable .contentSearchSettingsButton {
    background-color: #242428 !important;
    border-color: #404043 !important;
  }
  .contentSearchSuggestionTable .contentSearchSearchWithHeaderSearchText,
  .contentSearchSuggestionTable .contentSearchSuggestionEntry {
    color: #F9F9FA !important;
  }
  .contentSearchSuggestionTable .contentSearchOneOffItem {
    border-image: linear-gradient(transparent 18%, #404043 18%, #404043 82%, transparent 82%) 1 !important;
  }
  .contentSearchSuggestionTable .contentSearchSuggestionRow.selected,
  .contentSearchSuggestionTable .contentSearchOneOffItem.selected {
    background-color: #45A1FF !important;
    color: inherit !important;
  }
  .top-site-outer .default-icon,
  .top-site-outer .search-topsite {
    background-size: 42px !important;
  }
  .top-site-outer .top-site-icon {
    background-color: transparent !important;
  }
  .top-sites-list:not(.dnd-active) .top-site-outer:-moz-any(.active, :focus, :hover) .tile {
    box-shadow: inset 0 0 0 1px #45A1FF, 0 0 0 5px #45A1FF !important;
  }
  .top-site-outer .tile::before {
    content: unset !important;
  }
  .top-site-outer .context-menu-button {
    background-color: #404043 !important;
    fill: #F9F9FA !important;
  }
  .context-menu {
    background-color: #404043 !important;
    color: #F9F9FA !important
  }
  .context-menu .icon {
    fill: #F9F9FA !important;
  }
  .context-menu > ul > li > a:-moz-any(:focus, :hover),
  .context-menu > ul > li > button:-moz-any(:focus, :hover) {
    background-color: #45A1FF !important;
    color: inherit !important;
  }
}