Tou / Modo cascada manga

// ==UserScript==
// @name         Modo cascada manga
// @namespace    http://tampermonkey.net/
// @version      0.1
// @description  try to take over the world!
// @copyright 2021, Tou (https://openuserjs.org/users/Tou)
// @license MIT
// @author       Tou
// @match        https://ragnarokscan.com/manga/*
// @match        https://samuraiscan.com/manga/*
// @grant        none
// ==/UserScript==

(function () {
  'use strict';
  document.getElementById('modeALL').dispatchEvent(new MouseEvent("click"));
  document.getElementById('all').style.cursor = 'none';
  document.getElementsByClassName('col-xs-12 col-sm-8')[0].style.paddingRight = '0px';
  document.getElementsByClassName('col-xs-12 col-sm-8')[0].style.paddingLeft = '0px';

  var ele = document.getElementsByClassName('img-responsive');
  for (var i = 0; i < ele.length; i++) {
    ele[i].style.padding = "0px";
  }

  document.onkeydown = checkKey;

  function checkKey(e) {

    e = e || window.event;

    if (e.keyCode == '38') {
      // up arrow
    }
    else if (e.keyCode == '40') {
      // down arrow
    }
    else if (e.keyCode == '37') {
      prevChap();
    }
    else if (e.keyCode == '39') {
      nextChap();
    }

  }

})();