change-github-monospace-font.js

// ==UserScript==
// @name         GitHub Monospace Font Override
// @namespace    http://tampermonkey.net/
// @version      2025-09-23
// @description  Change the default monospace font used by GitHub
// @author       You
// @match        https://github.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=github.com
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    const style = document.createElement('style');
    style.innerHTML = `
      :root {
          --fontStack-monospace: 'Maple Mono' !important;
      }
    `;
    document.body.appendChild(style);
})();