GitHub UI Improvements user script

Github_UI_Improvements.user.js

// ==UserScript==
// @name           GitHub UI Improvements
// @namespace      https://gist.github.com/jasonsyoung/d569af9e12c1c25a6e8556c06dd6b766
// @match          https://github.com/*/*
// @match          https://gist.github.com/*
// @author         jasonsyoung
// @description    Widens any page with code or repository listing to 95%, adds the FuraCode Nerd Font Mono as the preferred font for these code areas, else fallback. More to come!
// @version        0.2
// ==/UserScript==
(function () {
    const css = `.repository-content * { font-family: 'FuraCode Nerd Font Mono Retina','FuraCode Nerd Font Mono','FuraCode NF Mono',SFMono-Regular,Consolas,Liberation Mono,Menlo,monospace !important; }`;
    const style = document.createElement('style');
    style.innerHTML = css;
    let interval = setInterval(function () {
        if (document.querySelector('.repository-content')) {
            widen()
        } else {
            window.console.log('repository content not found yet');
            document.head.removeChild(style);
        }
    }, 1000);
    function widen() {
        let container = document.querySelector('main > div.container-lg');
        if (!container.classList.contains('tamper-modified')) {
            container.style.maxWidth = '95%';
            document.head.appendChild(style);
        }
    }

    window.addEventListener('onbeforeunload', function() {
        clearInterval(interval)
    }, false);
}());