box-sizing controls how a box's total width and height is calculated. box-sizing can be set to one of the following two values: content-box | width and height control the size of the content box (thus the entire size of a box with border and padding will be larger). This is the default for most elements. |
border-box | width and height will take into account the size of border and padding. border-box is the default value for <table>, <select>, <button> as well for <input> whose type attribute is radio, checkbox, reset, button, submit, color or search. |