notes/_sass/support/mixins/_typography.scss

// Font size
$font-size-1: 9px;
$font-size-1-mq: 10px;
$font-size-2: 11px; //h4 - uppercased!, h6 not uppercased, text-small
$font-size-3: 12px; //h5
$font-size-4: 15px;
$font-size-5: 16px; //h3
$font-size-6: 18px; //h2
$font-size-7: 24px; 
$font-size-8: 32px;//h1
$font-size-9: 36px;
$font-size-10: 42px;
$font-size-10-mq: 48px;

@mixin fs-1 {
  font-size: $font-size-1 !important;

  @include mq(sm) {
    font-size: $font-size-1-mq !important;
  }
}

@mixin fs-2 {
  font-size: $font-size-2 !important;

  @include mq(sm) {
    font-size: $font-size-3 !important;
  }
}

@mixin fs-3 {
  font-size: $font-size-3 !important;

  @include mq(sm) {
    font-size: $font-size-4 !important;
  }
}

@mixin fs-4 {
  font-size: $font-size-4 !important;

  @include mq(sm) {
    font-size: $font-size-5 !important;
  }
}

@mixin fs-5 {
  font-size: $font-size-5 !important;

  @include mq(sm) {
    font-size: $font-size-6 !important;
  }
}

@mixin fs-6 {
  font-size: $font-size-6 !important;

  @include mq(sm) {
    font-size: $font-size-7  !important;
    line-height: $body-heading-line-height;
  }
}

@mixin fs-7 {
  font-size: $font-size-7 !important;
  line-height: $body-heading-line-height;

  @include mq(sm) {
    font-size: $font-size-8  !important;
  }
}

@mixin fs-8 {
  font-size: $font-size-8 !important;
  line-height: $body-heading-line-height;

  @include mq(sm) {
    font-size: $font-size-9!important;
  }
}

@mixin fs-9 {
  font-size: $font-size-9 !important;
  line-height: $body-heading-line-height;

  @include mq(sm) {
    font-size: $font-size-10 !important;
  }
}

@mixin fs-10 {
  font-size: $font-size-10 !important;
  line-height: $body-heading-line-height;

  @include mq(sm) {
    font-size: $font-size-10-mq !important;
  }
}