Answers for "set all tags to border-box box-sizing"

box-sizing border-box vs content-box css

box-sizing:content-box;
	"Default. The width and height properties (and min/max properties) includes only the content. Border and padding are not included"
box-sizing:border-box;	
	"The width and height properties (and min/max properties) includes content, padding and border"

box sizing border box

*{
 box-sizing: border-box;
 }