_responsive-fonts.scss

// =============================================================================
// Responsive Font Sizes
// =============================================================================
//
// Viewport sized typography with minimum and maximum values
//
//
// @param {Number}   $responsive  - Viewport-based size
// @param {Number}   $min         - Minimum font size (px)
// @param {Number}   $max         - Maximum font size (px)
//                                  (optional)
// @param {Number}   $fallback    - Fallback for viewport-
//                                  based units (optional)
//
// @example scss - 5vw font size (with 50px fallback),
//                 minumum of 35px and maximum of 150px
//  @include responsive-font(5vw, 35px, 150px, 50px);
//
@mixin responsive-font($responsive, $min, $max: false, $fallback: false) {
  $responsive-unitless: $responsive / ($responsive - $responsive + 1);
  $dimension: if(unit($responsive) == 'vh', 'height', 'width');
  $min-breakpoint: $min / $responsive-unitless * 100;

  @media (max-#{$dimension}: #{$min-breakpoint}) {
    font-size: $min;
  }

  @if $max {
    $max-breakpoint: $max / $responsive-unitless * 100;

    @media (min-#{$dimension}: #{$max-breakpoint}) {
      font-size: $max;
    }
  }

  @if $fallback {
    font-size: $fallback;
  }

  font-size: $responsive;