@mixin 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; } } }

@mixin 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; } } } }