12. $main-color: #ce4dd6; $style: solid; #navbar { border-bottom: { color: $main-color; style: $style; } } a { color: $main-color; &:hover { border-bottom: $style 1px; } } 2011 6 6 13. #navbar { border-bottom-color: #ce4dd6; border-bottom-style: solid; } a { color: #ce4dd6; } a:hover { border-bottom: solid 1px; } 2011 6 6