纯css修改复选框默认样式

input[type='checkbox']{
  width: 20px;
  height: 20px;
  background-color: #fff;
  -webkit-appearance:none;
  border: 1px solid #c9c9c9;
  border-radius: 2px;
  outline: none;
}
input[type=checkbox]:checked{
  background: url("../../../../static/img/checked.png")no-repeat center;
  background-size: 80%;
}