Answers for "how to change box sizing border box"

box sizing css

/*universial selector example to include padding, border, and margin 
in all box sizing totals*/
* {
  box-sizing: border-box;
}
/*example of div that will total 100% and not exceed it because it
is using the border-box property*/
div {
box-sizing: border-box;
width: 100%;
border: solid #5B6DCD 10px;
padding: 5px;
margin: 10px;
}

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"