js实现带三角符的手风琴效果

效果图：

图（1）初始图

图（2）点击展开图

代码如下：

 
 
 
 
  *{
  margin: 0;
  padding: 0;
  }
  li{
  list-style: none;
  }
  #list{
  width: 240px;
  border: 1px solid #666;
  margin: 20px auto;
  }
  #list .lis{
  }
  #list h2{
  height: 30px;
  line-height: 30px;
  overflow: hidden;
  background: lightsalmon;
  color: #f1f1f1;
  }
  #list h2.active{
  background: pink;
  height: 30px;
  line-height: 30px;
  overflow: hidden;
  color: #666;
  }
  #list h2.active div{
  display: inline-block;
  width: 0;
  height: 0;
  border-left: 8px solid transparent;
  border-top: 12px solid #666;
  border-right:8px solid transparent;
  border-bottom:2px solid transparent;
  margin-right: 4px;
  }
  #list h2 div{
  display: inline-block;
  width: 0;
  height: 0;
  border-left: 12px solid #f1f1f1;
  border-right: 6px solid transparent;
  border-bottom: 9px solid transparent;
  border-top:9px solid transparent;
  
  }
  #list .lis ul{
  display: none;
  }
  #list .lis ul li{
  line-height: 24px;
  border-bottom: 1px solid #666;
  text-indent: 15px;
  }
  #list .lis ul li.hover{
  background: lightgreen;
  color: #F8F8F8;
  }
  #list .lis ul li:first-of-type{
  border-top: 1px solid #ccc;
  }
  #list .lis:last-of-type ul li:last-of-type{
  border-bottom:none;
  }