box-sizing
box-sizing
border:10px solid red
box-sizing:content-box;
width:400px;
height:400px;
padding:100px;
border:100px solid silver
border:10px solid red
box-sizing:border-box;
width:400px;
height:400px;
padding:100px;
border:100px solid silver
-moz-box-sizing
border:10px solid red
-moz-box-sizing:content-box;
width:400px;
height:400px;
padding:100px;
border:100px solid silver
border:10px solid red
-moz-box-sizing:border-box;
width:400px;
height:400px;
padding:100px;
border:100px solid silver
-webkit-box-sizing
border:10px solid red
-webkit-box-sizing:content-box;
width:400px;
height:400px;
padding:100px;
border:100px solid silver
border:10px solid red
-webkit-box-sizing:border-box;
width:400px;
height:400px;
padding:100px;
border:100px solid silver
CSS Practice