outline
Definition
The outline property is a shorthand method of setting outline-width, outline-style and outline-color property values. An outline is similar to a border except that it is rendered over the element's box model so it does not affect the width or height used by the element. One useful application of outlines (seen in the screen shot below) is to show which form control currently has focus.

Example
input:focus, select:focus, textarea:focus {outline: 2px dotted blue}
This is equivalent to:
input:focus, select:focus, textarea:focus {outline-size: 2px;outline-style: dotted;outline-color: blue;}
Characteristics
Possible values
Default value
See individual properties
Applies to
All elements
Inherited
No
See also