hidden annotation on youtube.com for UserScript

an-no-tation.user.js

// ==UserScript==
// @name        anNOtation
// @namespace   http://noromanba.flavors.me
// @description hidden annotation on youtube.com for UserScript
// @include     *://www.youtube.com/*
// @grant       none
// @run-at      document-start
// @version     2016.3.17.0
// @homepage    https://gist.github.com/noromanba/87b2ecf7b18bdc78601c
// @downloadURL https://gist.github.com/noromanba/87b2ecf7b18bdc78601c/raw/an-no-tation.user.js
// @license     MIT License http://nrm.mit-license.org/2016
// @author      noromanba   http://noromanba.flavors.me
// @icon        https://upload.wikimedia.org/wikipedia/commons/thumb/8/81/PPEraser01.svg/32px-PPEraser01.svg.png
// @icon64      https://upload.wikimedia.org/wikipedia/commons/thumb/8/81/PPEraser01.svg/64px-PPEraser01.svg.png
// ==/UserScript==

// Icon (CC0 by JohannPoufPouf)
// https://commons.wikimedia.org/wiki/File:PPEraser01.svg

// Devel
// https://gist.github.com/noromanba/87b2ecf7b18bdc78601c


(() => {
    if (!/youtube\.com$/.test(location.hostname)) {
        return;
    }

    const addStyle = (() => {
        const parent = document.head || document.body || document.documentElement;

        const style = document.createElement('style');
        style.type = 'text/css';
        parent.appendChild(style);

        return (css) => {
            style.appendChild(document.createTextNode(css + '\n'));
        };
    })();

    addStyle([
        '.annotation', 
        '.video-annotations', 
        '[class|="ytp-cards-teaser"]'
    ] + '{ display: none !important; }');
})();