Box-sizing

As an adaptation of content from the Mozilla Developer Center, this page is only available under the CC-BY-SA license, 2.5, or later.

The CSS   property is used to alter the default CSS box model used to calculate widths and heights of elements. It is possible to use this property to emulate the behavior of browsers that do not correctly support the CSS box model specification. Firefox and Safari only support their own vendor extensions,  and.

Browser compatibility
-moz-box-sizing (Firefox) and -webkit-box-sizing (Safari) implement this part of the CSS specification. Opera (Mobile 10 and Desktop 10.5) and Internet Explorer 8 support the ordinary box-sizing property.