all color The border-color property sets the color of an element's four borders. This property can have from one to four values. Examples: border-color:red green blue pink; top border is red right border is green bottom border is blue left border is pink border-color:red green blue; top border is red right and left borders are green bottom border is blue border-color:red green; top and bottom borders are red right and left borders are green border-color:red; all four borders are red

style p.dotted {border-style: dotted;} p.dashed {border-style: dashed;} p.solid {border-style: solid;} p.double {border-style: double;} p.groove {border-style: groove;} 1px wh 1px gr 1ps bl 2px wh 2px gr 2px bl p.ridge {border-style: ridge;} 1px wh 1px gr 1ps bl 2px wh 2px gr 2px bl p.inset {border-style: inset;} 1px wh 1px gr 1ps bl 2px wh 2px gr 2px bl p.outset {border-style: outset;} 1px wh 1px gr 1ps bl 2px wh 2px gr 2px bl p.none {border-style: none;} p.hidden {border-style: hidden;} p.mix {border-style: dotted dashed solid double;} border-top-style: dotted; border-right-style: solid; border-bottom-style: dotted; border-left-style: solid; So, here is how it works: If the border-style property has four values: border-style: dotted solid double dashed; top border is dotted right border is solid bottom border is double left border is dashed If the border-style property has three values: border-style: dotted solid double; top border is dotted right and left borders are solid bottom border is double If the border-style property has two values: border-style: dotted solid; top and bottom borders are dotted right and left borders are solid If the border-style property has one value: border-style: dotted; all four borders are dotted thickness 1px or 1em. Or any number besides "1".