.nav .nav-item{
	background: #225544;
  width: 40px;
  height: 60px;
  margin-top: 40px;
  position: relative;
}

.nav .nav-item:before{
	content: "";
  display: block;
  width: 0;
  height: 0;
  position: absolute;
  top: -20px;
  left: 0;
  border-top: 20px solid transparent;
  border-left: 20px solid #225544;
  border-right: 20px solid #225544;
}

.nav .nav-item:after{
	content: "";
  display: block;
  width: 0;
  height: 0;
  position: absolute;
  bottom: -20px;
  left: 0;
  border-top: 20px solid #225544 ;
  border-left: 20px solid transparent;
  border-right: 20px solid transparent;
}





.nav .nav-item2{
	background: #225544;
  width: 40px;
  height: 60px;
  margin-top: 60px;
  position: relative;
  
  border-radius: 50px;
  
  behavior: url(http://www.zhangxinxu.com/study/201004/ie-css3.htc);
}

.nav .nav-item2:after{
	content: "";
  display: block;
  width: 50px;
  height: 50px;
  position: absolute;
  bottom: -40px;
  left: -5px;
  background: #225544;
  
  border-radius: 50px;
  
  behavior: url(http://www.zhangxinxu.com/study/201004/ie-css3.htc);
}

.box {
  width:256px;
  height:190px;
  text-indent:2em;
  font-size:2em;
  font-family:'华文新魏','华文行楷','微软雅黑';
  color:#a6813c;
  background:url(http://image.zhangxinxu.com/image/study/s/s256/mm1.jpg) no-repeat;
  position:relative;
  z-index:2;
  
  /* 现代浏览器以及使用了IE-CSS3的IE浏览器 */
  border-radius: 15px; 
  /* 现代浏览器以及使用了IE-CSS3的IE浏览器 */
  box-shadow: 10px 10px 20px #000; 

  behavior: url(http://www.zhangxinxu.com/study/201004/ie-css3.htc); /* 通知IE浏览器调用脚本作用于'box'类 */
}