.box
  @extend .block
  background: $white
  border-radius: 5px
  box-shadow: 0 2px 3px rgba($black, 0.1), 0 0 0 1px rgba($black, 0.1)
  display: block
  padding: 20px

a.box
  &:hover,
  &:focus
    box-shadow: 0 2px 3px rgba($black, 0.1), 0 0 0 1px $link
  &:active
    box-shadow: inset 0 1px 2px rgba($black, 0.2), 0 0 0 1px $link