Improved CSS text stroke using SASS and trigonometry.

mixins.scss

// Trigonometry functions from https://unindented.org/articles/trigonometry-in-sass/
@mixin stroke($width, $color, $step-multiplier: 8) {
  $unit: unit($width);
  $unitless: $width / ($width * 0 + 1);

  $steps: $unitless * $step-multiplier;
  $shadow: ''; // need a starter
  @for $i from 0 to $steps {
    $x: $width * cos(2 * pi() * $i / $steps);
    $y: $width * sin(2 * pi() * $i / $steps);
    @if $unit == 'px' {
      $x: round($x);
      $y: round($y);
    }
    $shadow: $shadow, $x $y 0 $color;
  }
  $shadow: str_slice('#{$shadow}', 2);

  text-shadow: #{$shadow};
}