Qiita の「1年以上経過しています」を刺激的にする。

qiita-strong-warn.js

// ==UserScript==
// @name         Powerup　Qiita warning
// @namespace    http://tampermonkey.net/
// @version      0.2
// @description  try to take over the world!
// @author       You
// @match        https://qiita.com/*
// @grant        none
// ==/UserScript==

(function() {
    'use strict';
    const alertElem = document.querySelector('.alert-warning > .fa-warning').parentElement;
    const timeElem = document.querySelector('time');
    const articleTime = Date.parse(timeElem.getAttribute('datetime'));
    const overDay = (Date.now() - articleTime) / (1000 * 60 * 60 * 24);
    let penaltyDay = overDay - 365;
    if (penaltyDay <= 0) {
        return;
    }
    // penaltyDay = 365 * 2;

    // Penalty Scale
    //  1 year ago <= => 5 year ago
    const PENALTY_MAX = 4 * 365;
    const penalty = Math.min(penaltyDay, 4 * 365);
    const pr = penalty / PENALTY_MAX; // penalty raito
    console.log(pr);


    // BG Color
    //  yellow                   red
    //  hsla(50, 81%, 94%, 1) => hsla(0, 81%, 50%, 1)
    alertElem.style.background = `hsla(${50 * (1 - pr)}, 81%, ${94 - 44 * pr}%, 1)`;
    //  hsl(38, 40%, 39%) => white
    if (pr >= 0.5) {
        alertElem.style.color = 'white';
    }

    // Box height
    //   15+0    =>  15+100
    alertElem.style.paddingTop = `${15 + pr * 100}px`;
    alertElem.style.paddingBottom = `${15 + pr * 100}px`;

    // Flashing
    // 5020    => 400
    alertElem.style.opacity = 0.9;
    setInterval(() => {
        alertElem.style.opacity = 1 - alertElem.style.opacity;
    }, 400 + 5020 * (1 - pr));
})();