fittext.scss

// Strip unit from a number value
// Usage :
//    strip-units(16px);
// Will return "16" (as a number)
@function strip-units($number) {
    @return $number / ($number * 0 + 1);
}

// Usage :
//    $resos: $screenSmall, $screenMedium, $screenXlarge;
//    @include fit-text(5.2px, $resos);
// 
@mixin fit-text($baseFontSize, $resolutions, $start: 1920, $ratio: 0.0075) {
    font-size: $baseFontSize*($start * $ratio);
    
    @each $breakpointItem in $resolutions {
        @media (max-width: $breakpointItem - 1) {
            font-size: $baseFontSize*(strip-units($breakpointItem)*$ratio);
        }
    }
}