=font-default($font-size: 18px, $line-height: ($font-size*1.6))
  font-size: $font-size
  line-height: $line-height
  font-family: 'Roboto', sans-serif
  font-weight: 400

=font-bold($font-size: 24px, $line-height: ($font-size*1.6))
  +font-default($font-size, $line-height)
  font-weight: 500

=font-light($font-size: 18px, $line-height: ($font-size*1.6))
  +font-default($font-size, $line-height)
  font-weight: 100