=outer-table-borders(!width = 2px, !color = black)
  :border= !width "solid" !color
  thead
    th
      :border-bottom= !width "solid" !color
  tfoot
    th, td
      :border-top= !width "solid" !color
  th
    &:first-child
      :border-right= !width "solid" !color

=inner-table-borders(!width = 2px, !color = black)
  th, td
    :border
      :right= !width "solid" !color
      :bottom= !width "solid" !color
      :left-width 0px
      :top-width 0px
    &:last-child,
    &.last
      :border-right-width 0px
  tbody, tfoot
    tr:last-child,
    tr.last
      th, td
        :border-bottom-width 0px