My SCSS mixin

_mixin.scss

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

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

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

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

@mixin column-gap ($val) {
	-webkit-column-gap: $val;
	   -moz-column-gap: $val;
	    -ms-column-gap: $val;
	        column-gap: $val;
}

@mixin column-width ($val) {
	-webkit-column-width: $val;
	   -moz-column-width: $val;
	    -ms-column-width: $val;
	        column-width: $val;
}

@mixin clearfix {
	&:before, &:after { content: ""; display: table; }
	&:after { clear: both; }
	*zoom: 1;
}

@mixin ir { display: block; border: 0; text-indent: -999em; overflow: hidden; background-color: transparent; background-repeat: no-repeat; text-align: left; direction: ltr; *line-height: 0; }

// $val in px
@mixin font-size ($val) {
	font-size: #{$val}px;
    font-size: #{$val/16}rem;
}

@mixin bg-gradient ($val1, $val2, $val3) {
	background: $val1;
	background: $val3;
	background: -webkit-gradient(linear, left top, left bottom, color-stop(0%, $val1), color-stop(100%,$val2));
	background: -webkit-linear-gradient(top,  $val1 0%, $val2 100%);
	background:    -moz-linear-gradient(top,  $val1 0%, $val2 100%);
	background:     -ms-linear-gradient(top,  $val1 0%, $val2 100%);
	background:      -o-linear-gradient(top,  $val1 0%, $val2 100%);
	background:    linear-gradient(to bottom, $val1 0%, $val2 100%);
	///*filter: progid:DXImageTransform.Microsoft.gradient( startColorstr='#{$val1}', endColorstr='#{$val2}',GradientType=0 );*/
}

@mixin font-face($name, $url, $weight, $style, $original) {
	@font-face {
		/*font-family: '#{$original}';*/
		font-family: $name;
		src: url('#{$url}.eot');
		src: url('#{$url}.eot?#iefix') format('embedded-opentype'),
		     url('#{$url}.woff') format('woff'),
		     url('#{$url}.ttf') format('truetype'),
		     url('#{$url}.svg##{$original}') format('svg');
		font-weight: $weight;
		font-style: $style;
	}
}

@mixin link ($par) {
	#{$par}:link, #{$par}:visited, #{$par}:hover, #{$par}:focus, #{$par}:active {
		@content;
	}
}

@mixin link-hfa ($par) {
	#{$par}:hover, #{$par}:focus, #{$par}:active {
		@content;
	}
}

@mixin link-hf ($par) {
	#{$par}:hover, #{$par}:focus {
		@content;
	}
}

@mixin mq-min ($width, $ratio: 1) {
	@if $ratio > 1 {
		@if $width > 0 {
			@include mq-comment($width, $ratio);
			@media only screen and (min-width: $width) and (-webkit-min-device-pixel-ratio: $ratio),
			       only screen and (min-width: $width) and (min--moz-device-pixel-ratio: $ratio),
			       only screen and (min-width: $width) and (min-device-pixel-ratio: $ratio) {
				@content;
			}
		}
		@else {
			@include mq-comment($width, $ratio);
			@media only screen and (-webkit-min-device-pixel-ratio: $ratio),
			       only screen and (min--moz-device-pixel-ratio: $ratio),
			       only screen and (min-device-pixel-ratio: $ratio) {
			    @content;
			}
		}
	}
	@else {
		@include mq-comment($width, $ratio);
		@media only screen and (min-width: $width) {
			@content;
		}
	}
}

$fix-mqs: false !default;

@mixin mq-min-check ($width, $ratio: 1) {
	@if $fix-mqs {
		@if $fix-mqs >= $width and $ratio == 1 {
				@content;
		}
	}
	@else {
		@include mq-min($width, $ratio) {
			@content;
		}
	}
}

// iPhone landscape
@mixin mq-iphone-l {
	@if $fix-mqs == false {
		/* iPhone landscape
		   ========================================================================== */
		@media only screen and (orientation: landscape) and (-webkit-min-device-pixel-ratio: 1.5) {
			@content;
		}
	}
}

// iPhone portrait
@mixin mq-iphone-p {
	@if $fix-mqs == false {
		/* iPhone portrait
		   ========================================================================== */
		@media only screen and (orientation: portrait) and (-webkit-min-device-pixel-ratio: 1.5) {
			@content;
		}
	}
}

@mixin mq-comment ($width, $ratio) {
/* #{$width} #{$ratio}x
   ========================================================================== */
}