为什么 给a添加为元素后，最后无法通过last-child来去除最后这条填充的线条？
.nav li a:after{
content: "";
position: absolute;
right: 0px;
top: 18px;
width: 1px;
height: 14px;
text-shadow: none;
background: linear-gradient(to bottom,#f82f87,#B0363F,#f82f87)
}
.nav li a:last-child:after{
height:0px;
width:0px;
}
