JetBrains Mono font for Github.user.js

// ==UserScript==
// @name        JetBrains Mono font for Github
// @namespace   local.greasemonkey.jetbrainsmonoforgithub
// @include     https://github.com/*
// @version     2
// @grant       none
// ==/UserScript==

let fontdef = "JetBrains Mono, SFMono-Regular, Consolas, Liberation Mono, Menlo, monospace ! important"; // Set your font here.

// Function helper to inject css
function addGlobalStyle(css) {
    let head, style;
    head = document.getElementsByTagName('head')[0];
    if (!head) { return; }
    style = document.createElement('style');
    style.type = 'text/css';
    style.innerHTML = css;
    head.appendChild(style);
}

addGlobalStyle(`@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-Bold-Italic.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-Bold-Italic.woff') format('woff');
  font-weight: 700;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-Bold.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-Bold.woff') format('woff');
  font-weight: 700;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-ExtraBold-Italic.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-ExtraBold-Italic.woff') format('woff');
  font-weight: 800;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-ExtraBold.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-ExtraBold.woff') format('woff');
  font-weight: 800;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-Italic.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-Italic.woff') format('woff');
  font-weight: 400;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-Medium-Italic.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-Medium-Italic.woff') format('woff');
  font-weight: 500;
  font-style: italic;
  font-display: swap;
}

@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-Medium.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-Medium.woff') format('woff');
  font-weight: 500;
  font-style: normal;
  font-display: swap;
}

@font-face {
  font-family: 'JetBrains Mono';
  src: url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff2/JetBrainsMono-Regular.woff2') format('woff2'),
    url('https://cdn.jsdelivr.net/gh/JetBrains/JetBrainsMono/web/woff/JetBrainsMono-Regular.woff') format('woff');
  font-weight: 400;
  font-style: normal;
  font-display: swap;
}`);

// Apply the font-family definition to code styles.
addGlobalStyle(
  '.blob-code { font-family: ' + fontdef + '; } ' +
  '.blob-num { font-family: ' + fontdef + '; } ' +
  '');