CSS Box-Sizing

Box original - 470px x 370px


    width: 400px;
    height: 300px;
    margin: 20px auto;

    padding: 20px;
    border: 15px solid red;

Box revise - 400px x 300px


    width: 330px;
    height: 300px;
    margin: 20px auto;

    padding: 20px;
    border: 51px solid red;

Box new - 400px x 300px


    width: 400px;
    height: 300px;
    margin: 20px auto;

    padding: 20px;
    border: 15px solid red;

     -webkit-box-sizing: border-box;
     -moz-box-sizing: border-box;
          box-sizing: border-box;