Responsive vh/vw based font sizes

rf.scss

@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;
}