-webkit-box-sizing: border-box; /* Safari/Chrome, other WebKit */
-moz-box-sizing: border-box; /* Firefox, other Gecko */
box-sizing: border-box; /* Opera/IE 8+ */#example1 {
box-sizing: border-box;
}header, ul, nav, li, a /* other elements */{
display: block;
-webkit-box-sizing: border-box;
-moz-box-sizing: border-box;
box-sizing: border-box;*{
box-sizing: border-box;
}html {
box-sizing: border-box;
}
*, *:before, *:after {
box-sizing: inherit;
}Sintaxe formal:
content-box | (en-US) border-box