通过::after选择器给input勾选

<input type="checkbox" id="checkboxbtns" style="margin-right:0.875em;" checked="">

input[type=checkbox]:checked::after  {

1. content: url(../images/register/checked.jpg);
2. display: block;
3. position: relative;
4. top: 2px;
5. left: 0;
6. width: 24px;
7. height: 24px;
8. background: none;

}