Styling a radio box with CSS

the CSS:

label {  
    display: inline-block;  
    cursor: pointer;  
    position: relative;  
    padding-left: 25px;  
    margin-right: 15px;  
    font-size: 13px;  

input[type=radio] {  
    display: none;  

label:before {  
    content: "";  
    display: inline-block;  

    width: 16px;  
    height: 16px;  

    margin-right: 10px;  
    position: absolute;  
    left: 0;  
    bottombottom: 1px;  
    background-color: #aaa;  
    box-shadow: inset 0px 2px 3px 0px rgba(0, 0, 0, .3), 0px 1px 0px 0px rgba(255, 255, 255, .8);  

input[type=radio]:checked + label:before {  
    content: "\2022";  
    color: #f3f3f3;  
    font-size: 30px;  
    text-align: center;  
    line-height: 18px;  

.radio label:before {  
    border-radius: 8px;  

the HTML

<div class="radio">  
    <input id="male" type="radio" name="gender" value="male">  
    <label for="male">Male</label>  
    <input id="female" type="radio" name="gender" value="female">  
    <label for="female">Female</label>