Ryf ES6 Helper & Styler

RT.

// ==UserScript==
// @name         Ryf ES6 Helper & Styler
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  RT.
// @author       Maniacata
// @match        https://es6.ruanyifeng.com/
// @grant        none
// ==/UserScript==

(function () {

    //document.body.style.filter = "invert(1)";
    //document.body.style.background = "#333";

    document.getElementById("content").style.width = "60vw";

    let hSidebar = document.getElementById("sidebar");
    hSidebar.style.opacity = ".1";
    hSidebar.style.transition = "all .5s ease-in-out";



    hSidebar.addEventListener("mouseover", () => {
        hSidebar.style.opacity = "1";
    });
    hSidebar.addEventListener("mouseout", () => {
        hSidebar.style.opacity = ".1";
    });

    document.body.addEventListener("keydown", (event) => {
        var hash = getHash().nav;
        for (var i = 0; i < menu.length; i++) {
            if (hash === '') break;
            if (menu[i] === '#' + hash) break;
        }

        if (event.key === "ArrowLeft") {
            location.hash = menu[i - 1];
        }
        if (event.key === "ArrowRight") {
            location.hash = menu[i + 1];
        }
    });

})();