li::before {
content: '';
position: absolute;
top: 50%;
left: 0;
width: .36rem;
height: .36rem;
margin-top: -.18rem;
border-radius: .36rem;
border: .01rem solid #279ECD;
}
li.active::before {
background-color: #279ECD;
}
$('ul').click('click','li',function(){
$(this).addClass("active").siblings().removeClass("active");
})