The border-style property sets the style of an element's border. This property must be specified for the border to be visible.
If four values are given, they apply to top, right, bottom, and left border style, respectively. If one value is given, it applies to all sides. If two or three values are given, the missing values are taken from the opposite side.
[ none | dotted | dashed | solid | double | groove | ridge | inset | outset ]{1,4}
#xy34 { border-style: solid dotted }