as the plugin name suggests, the 'PDF Dark Reader' plugin provides you a dark PDF page. Local files are not supported due to browser restrictions.
// ==UserScript==
// @name PDF Dark Reader
// @namespace tolix123.github.io
// @version 0.1
// @license MIT
// @description as the plugin name suggests, the 'PDF Dark Reader' plugin provides you a dark PDF page. Local files are not supported due to browser restrictions.
// @author Tolix123
// @match *://*/*.pdf
// @match file://*/*.pdf
// @grant none
// ==/UserScript==
(function() {
'use strict';
var cover = document.createElement("div");
let css = `
position: fixed;
pointer-events: none;
top: 0;
left: 0;
width: 100vw;
height: 100vh;
background-color: #DDDDDD;
mix-blend-mode: difference;
z-index: 1;
`// Change the colour in the background-color task.
cover.setAttribute("style", css);
document.body.appendChild(cover);
})();