src/_sass/_mixins.scss

@mixin box-shadow($shadow...) {
  -webkit-box-shadow: $shadow;
     -moz-box-shadow: $shadow;
          box-shadow: $shadow;
}

@mixin border-radius($radius...) {
  -webkit-border-radius: $radius;
     -moz-border-radius: $radius;
          border-radius: $radius;
}

@mixin border-top-left-radius($radius...) {
  -webkit-border-top-left-radius: $radius;
     -moz-border-radius-topleft:  $radius;
          border-top-left-radius: $radius;
}

@mixin border-top-right-radius($radius...) {
  -webkit-border-top-right-radius: $radius;
     -moz-border-radius-topright:  $radius;
          border-top-right-radius: $radius;
}

@mixin transition($transition...) {
  -webkit-transition: $transition;
     -moz-transition: $transition;
       -o-transition: $transition;
          transition: $transition;
}

@mixin user-select($select...) {
  -webkit-user-select: $select;    /* Chrome all / Safari all */
     -moz-user-select: $select;    /* Firefox all */
      -ms-user-select: $select;    /* IE 10+ */
       -o-user-select: $select;
          user-select: $select;
}

@mixin keyframes($name) {
  @-o-keyframes #{$name} { @content };
  @-moz-keyframes #{$name} { @content };
  @-webkit-keyframes #{$name} { @content };
  @keyframes #{$name} { @content };
}

@mixin animation($animation...) {
  -o-animation: $animation;
  -moz-animation: $animation;
  -webkit-animation: $animation;
  animation: $animation;
}

@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: eot woff2 woff 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-weight: $weight;
		src: $src;
	}
}