radio样式

.radio{
position: relative;
border: 1px solid #999;
border-radius: 50%;
width: 12px;
height: 12px;
background-color: #eee;
}

.radio.active:after {
content: "";
display: table;
position: absolute;
top: 2px;
left: 2px;
width:6px;
height: 6px;
border-radius: 50%;
background-color: #666;
}