style.user.css

/* ==UserStyle==
@name           Pretty Codewars
@version        3.0.0
@namespace      github.com/goodjack/pretty-codewars
@description    Larger font size, increased line height, and the beautiful Fira Code font.
@author         goodjack <goodjack@users.noreply.github.com> (https://github.com/goodjack)
@homepageURL    https://github.com/goodjack/pretty-codewars
@supportURL     https://github.com/goodjack/pretty-codewars/issues
@updateURL      https://raw.githubusercontent.com/goodjack/pretty-codewars/master/style.user.css
@license        CC-BY-4.0
==/UserStyle== */

@-moz-document domain("codewars.com") {
  @import url("https://fonts.googleapis.com/css2?family=Fira+Code:wght@300;400;500;600;700&display=swap");

  .CodeMirror pre.CodeMirror-line {
    font-size: 17px;
    line-height: 1.6;
    font-family: "Fira Code";
  }

  code {
    font-family: "Fira Code" !important;
  }
}