I noticed that your code didn't that good so I make cleaner one:

// ==UserScript==
// @name         cleanCssTricksAds
// @namespace    http://tampermonkey.net/
// @version      0.12
// @description  clean css-tricks.com ads
// @author       [email protected]
// @match        *.css-tricks.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=css-tricks.com
// @grant        none
// @license      MIT
// @run-at       document-body
// ==/UserScript==
(function() {
'use strict';
var css =
`
.page-wrap main header.mega-header { padding:0 }
.page-wrap main .articles-and-sidebar { grid-template-columns:minmax(0,1fr) }
.page-wrap main .entry-unrelated.sidebar,
.page-wrap main .popular-articles > .popular-header,
.page-wrap main .header-sponsor-grid .header-sponsor,
.page-wrap main .site-note { display:none }
.page-wrap main .header-sponsor-grid { grid-template-columns:1fr }
.page-wrap main .mega-header > p,
.page-wrap main .header-sponsor-grid .header-text .header-intro,
.page-wrap main .header-sponsor-grid .header-text .header-intro p { max-width:unset }
footer.site-footer { margin: calc(var(--gap)*3) 0 0 0 }`
var style = document.createElement('style');
style.textContent = css;
document.head.appendChild(style);
})();

I noticed that your code didn't that good so I make cleaner one:

// ==UserScript==
// @name         cleanCssTricksAds
// @namespace    http://tampermonkey.net/
// @version      0.12
// @description  clean css-tricks.com ads
// @author       [email protected]
// @match        *.css-tricks.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=css-tricks.com
// @grant        none
// @license      MIT
// @run-at       document-body
// ==/UserScript==
(function() {
'use strict';
var css =
`
.page-wrap main header.mega-header { padding:0 }
.page-wrap main .articles-and-sidebar { grid-template-columns:minmax(0,1fr) }
.page-wrap main .entry-unrelated.sidebar,
.page-wrap main .popular-articles > .popular-header,
.page-wrap main .header-sponsor-grid .header-sponsor,
.page-wrap main .site-note { display:none }
.page-wrap main .header-sponsor-grid { grid-template-columns:1fr }
.page-wrap main .mega-header > p,
.page-wrap main .header-sponsor-grid .header-text .header-intro,
.page-wrap main .header-sponsor-grid .header-text .header-intro p { max-width:unset }
footer.site-footer { margin: calc(var(--gap)*3) 0 0 0 }`
var style = document.createElement('style');
style.textContent = css;
document.head.appendChild(style);
})();

I noticed that your code didn't that good so I make cleaner one:

// ==UserScript==
// @name         cleanCssTricksAds
// @namespace    http://tampermonkey.net/
// @version      0.12
// @description  clean css-tricks.com ads
// @author       [email protected]
// @match        *.css-tricks.com/*
// @icon         https://www.google.com/s2/favicons?sz=64&domain=css-tricks.com
// @grant        none
// @license      MIT
// @run-at       document-body
// ==/UserScript==
(function() {
'use strict';
var css =
`
.page-wrap main header.mega-header { padding:0 }
.page-wrap main .articles-and-sidebar { grid-template-columns:minmax(0,1fr) }
.page-wrap main .entry-unrelated.sidebar,
.page-wrap main .popular-articles > .popular-header,
.page-wrap main .header-sponsor-grid .header-sponsor,
.page-wrap main .site-note { display:none }
.page-wrap main .header-sponsor-grid { grid-template-columns:1fr }
.page-wrap main .mega-header > p,
.page-wrap main .header-sponsor-grid .header-text .header-intro,
.page-wrap main .header-sponsor-grid .header-text .header-intro p { max-width:unset }
footer.site-footer { margin: calc(var(--gap)*3) 0 0 0 }`
var style = document.createElement('style');
style.textContent = css;
document.head.appendChild(style);
})();

Thanks for your advises