Default fonts

Replace web fonts with browser's default fonts

K instalaci tototo skriptu si budete muset nainstalovat rozšíření jako Tampermonkey, Greasemonkey nebo Violentmonkey.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Violentmonkey.

K instalaci tohoto skriptu si budete muset nainstalovat rozšíření jako Tampermonkey nebo Userscripts.

You will need to install an extension such as Tampermonkey to install this script.

K instalaci tohoto skriptu si budete muset nainstalovat manažer uživatelských skriptů.

(Už mám manažer uživatelských skriptů, nechte mě ho nainstalovat!)

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install an extension such as Stylus to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

You will need to install a user style manager extension to install this style.

(Už mám manažer uživatelských stylů, nechte mě ho nainstalovat!)

// ==UserScript==
// @name         Default fonts
// @version      1.1
// @description  Replace web fonts with browser's default fonts
// @author       KenHV
// @namespace    https://kenhv.com
// @supportURL   https://kenhv.com
// @homepageURL  https://kenhv.com
// @match        *://*/*
// @grant        none
// @run-at       document-start
// ==/UserScript==

(function () {
  "use strict";

  // Cache to keep track of processed rules and stylesheets
  const processedRules = new WeakSet();
  const processedStyleSheets = new WeakSet();

  function fontReplace() {
    Array.from(document.styleSheets).forEach((styleSheet) => {
      if (processedStyleSheets.has(styleSheet)) {
        return;
      }

      let rules;
      try {
        rules = Array.from(styleSheet.cssRules);
      } catch (err) {
        return;
      }

      rules.forEach((rule) => {
        if (rule instanceof CSSStyleRule && !processedRules.has(rule)) {
          if (rule.style.fontFamily.includes("sans")) {
            rule.style.fontFamily = "sans-serif";
            processedRules.add(rule);
            return;
          }
          if (rule.style.fontFamily.includes("serif")) {
            rule.style.fontFamily = "serif";
            processedRules.add(rule);
            return;
          }
          if (rule.style.fontFamily.includes("mono")) {
            rule.style.fontFamily = "monospace";
            processedRules.add(rule);
            return;
          }
          processedRules.add(rule);
        }
      });

      processedStyleSheets.add(styleSheet);
    });
  }

  fontReplace();

  // Use MutationObserver to react to changes in the DOM
  const observer = new MutationObserver(() => {
    fontReplace();
  });

  observer.observe(document.documentElement, {
    childList: true,
    subtree: true,
  });
})();