自定义 单选框按钮

<input type="radio" class="rdo" name="sex" checked>

<input type="radio" class="rdo" name="sex">

CSS部分

.rdo {
20px;
height: 0px;
background-color: #000;
margin-right: 30px;
border-radius: 50%;
position: relative;
}
.rdo:before,.rdo:after {
content: '';
display: block;
position: absolute;
border-radius: 50%;
transition: .3s ease;
}
.rdo:before {
top: 0px;
left: 0px;
18px;
height: 18px;
background-color: #fff;
border: 1px solid #000;
}
.rdo:after {
top: 6px;
left: 6px;
8px;
height: 8px;
background-color: #fff;
}
.rdo:checked:after {
top: 4px;
left: 4px;
12px;
height: 12px;
background-color:#ea879a;
}
.rdo:checked:before {
border-color:#ea879a;
}