math variables and notations highlighter

Highlights mathematical variables and notations (MathJax, Italic) with a simple blue background, so long paragraphs are easier to read. Primarily focused for usage on websites such as codeforces and project euler.

You will need to install an extension such as Tampermonkey, Greasemonkey or Violentmonkey to install this script.

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

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

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

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

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

(I already have a user script manager, let me install it!)

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.

(I already have a user style manager, let me install it!)

// ==UserScript==
// @name         math variables and notations highlighter
// @namespace    https://github.com/FreGeh
// @version      1.5
// @license      GPL-3.0-or-later
// @description  Highlights mathematical variables and notations (MathJax, Italic) with a simple blue background, so long paragraphs are easier to read. Primarily focused for usage on websites such as codeforces and project euler.
// @icon         https://cdn-icons-png.flaticon.com/128/43/43102.png
// @author       fregeh
// @match        *://*/*
// @grant        none
// ==/UserScript==


(function() {
    'use strict';

    // Define a function to style elements.
    function highlightElements() {
        // Style tex-span variables.
        const texElements = document.querySelectorAll('.tex-span i');
        texElements.forEach(variable => {
            variable.style.backgroundColor = 'rgba(160, 200, 255, 0.7)'; // Less transparent blue
            variable.style.borderRadius = '3px';
            variable.style.padding = '0 2px';
        });

        // Style MathJax elements.
        const mathJaxElements = document.querySelectorAll('.MathJax');
        mathJaxElements.forEach(element => {
            element.style.backgroundColor = 'rgba(160, 200, 255, 0.7)'; // Less transparent blue
            element.style.borderRadius = '3px';
            element.style.padding = '2px 4px';
            element.style.margin = '0 2px';
            element.style.display = 'inline-block';
        });

        // Style italic and subscript variables in problem_par.
        const problemVars = document.querySelectorAll('.problem_par i, .problem_par sub');
        problemVars.forEach(variable => {
            variable.style.backgroundColor = 'rgba(160, 200, 255, 0.7)';
            variable.style.borderRadius = '3px';
            variable.style.padding = '0 2px';
        });
    }

    // Apply styling to existing elements.
    highlightElements();

    // Observe DOM changes for dynamic content.
    const observer = new MutationObserver(mutations => {
        mutations.forEach(mutation => {
            mutation.addedNodes.forEach(node => {
                if (node.nodeType === 1) {
                    if (node.matches('.tex-span i, .MathJax, .problem_par i, .problem_par sub')) {
                        highlightElements();
                    } else {
                        node.querySelectorAll('.tex-span i, .MathJax, .problem_par i, .problem_par sub').forEach(highlightElements);
                    }
                }
            });
        });
    });

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