outline-style, no siempre tiene que fastidiar...

div { outline-style: none; outline-width: 1px; }

div { outline-style: dotted; outline-width: 1px; }

div { outline-style: dashed; outline-width: 1px; }

div { outline-style: solid; outline-width: 1px; }

div { outline-style: double; outline-width: 1px; }

div { outline-style: groove; outline-width: 1px; }

div { outline-style: ridge; outline-width: 1px; }

div { outline-style: inset; outline-width: 1px; }

div { outline-style: outset; outline-width: 1px; }

div { outline-style: none; outline-width: 4px; }

div { outline-style: dotted; outline-width: 4px; }

div { outline-style: dashed; outline-width: 4px; }

div { outline-style: solid; outline-width: 4px; }

div { outline-style: double; outline-width: 4px; }

div { outline-style: groove; outline-width: 4px; }

div { outline-style: ridge; outline-width: 4px; }

div { outline-style: inset; outline-width: 4px; }

div { outline-style: outset; outline-width: 4px; }