GMail diet - Greasemonkey / Tampermonkey script that makes the new GMail a bit more like the old GMail

gmail-diet-greasemonkey.js

// ==UserScript==
// @name         GMail Diet
// @namespace    http://johnstanfield.com/
// @version      0.1
// @description  deflates the ~3Q2018 GMail web app.  The GMail web app prior to the version released around Q3 2018 was nice and compact.  The new version has extra padding that is trimmed by this script.  Tested in Tampermonkey on Chrome 56.
// @author       John Stanfield
// @match        *://mail.google.com/*
// @grant        none
// ==/UserScript==


// thank you Hors Sujet
// https://stackoverflow.com/questions/23683439/gm-addstyle-equivalent-in-tampermonkey#answer-33176845
function GM_addStyle(css) {
  const style = document.getElementById("GM_addStyleBy8626") || (function() {
    const style = document.createElement('style');
    style.type = 'text/css';
    style.id = "GM_addStyleBy8626";
    document.head.appendChild(style);
    return style;
  })();
  const sheet = style.sheet;
  sheet.insertRule(css, (sheet.rules || sheet.cssRules || []).length);
}

(function() {
    'use strict';

    // deflate emails in list
    GM_addStyle('tr.zA { padding-top: 2px; padding-bottom: 2px; }');

    // remove right sidebar
    GM_addStyle('.nH.bAw.nn { display:none }');

    // deflate labels
    GM_addStyle('.TN.bzz, .TN.aY7xie { height: 20px }');
})();