border width in percentage

1.element {
2  border-width: 2px;
3}

1element {
2	border-width: 10px;
3  	/* Or use shorthand border property */
4  	/* width style colour */
5  	border: 10px solid black;
6}

1
2div {border-width: thin;} 

1You can not set Border Width in the Percentage its the rule 
2But you can able to do this just by wrapping into a new div 
3and in most of the cases you did not need that