project_euler_difficulty_on_progress.js

// this code pasted on Project Euler console site shows difficulty of tasks using colors

const round = n => Math.round(n);
[...document.querySelectorAll('.smaller')].forEach(e=>{;
    const diff = (+e.innerHTML.match(/\d{1,3}/)[0]) / 100 * 255;
    const color = `rgba(${diff},${255-diff},0,1)`;
    e.parentNode.parentNode.parentNode.style.backgroundColor = color;
});