pixiv larger thumbnails

// ==UserScript==
// @namespace   https://github.com/ToostInc/userscripts
// @icon        data:image/png;base64,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
// @name        Pixiv Large Thumbnails
// @description Original size thumbnails for Pixiv
// @author      Toost Inc.
// @version     0.1
// @include     /^https?:\/\/www\.pixiv\.net\/member_illust\.php?.*mode=medium.*$/
// @license     MIT
// @grant       none
// ==/UserScript==

// Edit the number between the double quotes to set the size of the thumbnails
var maxThumbnailSize = "1080px"

var domLinkToLarger = document.querySelector("div.works_display > a");
var domImageDisplay = domLinkToLarger.querySelector("img");

var startIndexOfIdString = domLinkToLarger.href.indexOf("member_illust.php?mode=big&illust_id=");
if (startIndexOfIdString != -1) {
	var big_page_result = new XMLHttpRequest();
	big_page_result.onreadystatechange = function()
  {
		if (big_page_result.readyState == 4 && big_page_result.status == 200) {
			var parser = new DOMParser();
			var result_document = parser.parseFromString(big_page_result.responseText, "text/html");
			domLinkToLarger.href = result_document.querySelector("img").src;
			domImageDisplay.style = "max-width: " + maxThumbnailSize + ";"
			domImageDisplay.src = result_document.querySelector("img").src;
		}
  }
	big_page_result.open("GET", domLinkToLarger.href, false);
	big_page_result.send();
}