$base-font-size: 16px; // Default font-size

@function em($pixels, $context: $base-font-size) {
  @if (unitless($pixels)) {
    $pixels: $pixels * 1px;
  }
  @if (unitless($context)) {
    $context: $context * 1px;
  }

  @return $pixels / $context * 1rem;
}

@function str-replace($string, $search, $replace: "") {
	$index: str-index($string, $search);

	@if $index {
		@return str-slice($string, 1, $index - 1) + $replace + str-replace(str-slice($string, $index + str-length($search)), $search, $replace);
	}

	@return $string;
}

@mixin font-face($name, $path, $weight: null, $style: null, $exts: woff2 woff eot ttf svg) {
	$src: null;

	$extmods: (
		eot: "?",
		svg: "#" + str-replace($name, " ", "_")
	);

	$formats: (
		otf: "opentype",
		ttf: "truetype"
	);

	@each $ext in $exts {
		$extmod: if(map-has-key($extmods, $ext), $ext + map-get($extmods, $ext), $ext);
		$format: if(map-has-key($formats, $ext), map-get($formats, $ext), $ext);
		$src: append($src, url(quote($path + "." + $extmod)) format(quote($format)), comma);
	}

	@font-face {
		font-family: quote($name);
		font-style: $style;
		font-display: swap;
		font-weight: $weight;
		src: $src;
	}
}

@mixin font($name: "IntervalNextBook") {
    font-family: $name, sans-serif;
}