Chrome user Script Demo

demo.user.js

// ==UserScript==
// @name           Demo
// @namespace      http://youdomain.com
// @include        http://www.douban.com/*
// @description    Demo
// @version        20101015
// ==/UserScript==
/*globals XPathResult, GM_getValue, GM_setValue, localStorage, unescape,
frameElement */

"use strict";

( function() {
    var BASE_CSS = "" +
      "#entries.comment-cards .entry-comments {" +
      "  background-color: transparent !important;" +
      "}"
    function addStyle( css ) {
      var style = document.createElement( "style" );
      style.type = "text/css";
      style.textContent = css; // innerHTML throws NO_MODIFICATION_ALLOWED_ERR
      document.getElementsByTagName( "head" )[0].appendChild( style );
      return style;
    }
    console.log("hi")
    addStyle( BASE_CSS );
}() );