CSS3 box-sizing属性详解

<style type="text/css">
    .content-box{
        box-sizing:content-box;
        -moz-box-sizing:content-box;
        width: 100px;
        height: 100px;
        padding: 20px;
        border: 5px solid #E6A43F;
        background: blue;
    }
    .padding-box{
        box-sizing:padding-box;
        -moz-box-sizing:padding-box;
        width: 100px;
        height: 100px;
        padding: 20px;
        border: 5px solid #186645;
        background: red;                
    }
    .border-box{
        box-sizing:border-box;
        -moz-box-sizing:border-box;
        width: 100px;
        height: 100px;
        padding: 20px;
        border: 5px solid #3DA3EF;
        background: yellow;
    }
</style>