The dotted gray line is the border box
dotted | dashed | solid | double
groove | ridge | inset | outset

## partial attributes merged

outline:thin solid red;
outline:red thin solid;
{ outline:thin solid; }{outline:blue; } (merged, reset all - color has no effect)
{ outline:thin solid; }{outline-color:green; } (merged, overwrite only color)
{ outline:thin solid; }{outline:blue; } (merged, reset all - color has no effect)
{ outline:thin solid; }{outline-color:green; } (merged, overwrite only color)
{ outline:thin blue solid; }{outline-color:green; } (merged, overwrite only color)
{ outline:thin blue solid; }{outline-style:dashed; } (merged, overwrite only style)
{ outline:thin blue solid; }{outline-width:thick; } (merged, overwrite only width)
{ outline:thin blue solid; }{outline-width:medium; } (merged, overwrite only width)
{ outline:thin blue solid; }{outline-width:3pt; } (merged, overwrite only width)