.introTips i{ position: absolute; display: block; top: 8px; right: 8px; width: 0; height: 0; font-size: 0; line-height: 0; border-top: 5px solid #fff; border-right: 3px solid transparent; border-left: 3px solid transparent; }
原文：http://www.cnblogs.com/zhidong123/p/4940273.html