server-tools/base_fontawesome/static/src/css/fontawesome.css

@font-face {
  font-family: 'FontAwesome';
  src: url("../../lib/fontawesome-5.7.1/webfonts/fa-solid-900.eot");
  src: url("../../lib/fontawesome-5.7.1/webfonts/fa-solid-900.eot?#iefix") format("embedded-opentype"), url("../../lib/fontawesome-5.7.1/webfonts/fa-solid-900.woff2") format("woff2"), url("../../lib/fontawesome-5.7.1/webfonts/fa-solid-900.woff") format("woff"), url("../../lib/fontawesome-5.7.1/webfonts/fa-solid-900.ttf") format("truetype"), url("../../lib/fontawesome-5.7.1/webfonts/fa-solid-900.svg#fontawesome") format("svg");
  ont-weight: normal;
  font-style: normal;
  }

.btn.fa,
.btn.fas,
.btn.far,
.btn.fal,
.btn.fab {
  font-weight: 900;
 }