效果CSS实现三角

1.  

   <view class="hd"></view>.hd {
2.  
   content: "";
3.  
   height: 16rpx;
4.  
   16rpx;
5.  
   border- 4rpx 4rpx 0 0;
6.  
   border-color: red;
7.  
   border-style: solid;
8.  
   transform: rotate(-45deg);
9.  
   position: absolute;
10.  
    top: 20rpx;
11.  
    left: 30rpx;
12.  
    }
13.  
    .hd:hover {
14.  
    transform: rotate(135deg);
15.  
16. 重点是：content 设置为空