add background to opponent's field grid
// ==UserScript==
// @name Opponent's Field Background Script
// @namespace http://tampermonkey.net/
// @version 0.1
// @description add background to opponent's field grid
// @author Oki
// @match https://*.jstris.jezevec10.com/*
// @grant none
// ==/UserScript==
/**************************
Opponent's Field Background Script
**************************/
colorName = "black"
opacity = 0.5
var customStyle=document.createElement("style");
customStyle.innerHTML='.players .bgLayer{background-color:'+colorName+';opacity:'+opacity+';}';
document.body.appendChild(customStyle);