SCSS common mixins with cross browser style definitions

Mixins.scss

// Global reusable mixins

/*
 * Version: 2.0 (2 Feb 2012)
 * 
 * Copyright (c) 2011 Robert Koritnik
 * Licensed under the terms of the MIT license
 * http://www.opensource.org/licenses/mit-license.php
 */

@mixin noOuterDimensions {
	margin: 0;
	border: 0 none;
	outline: 0 none;
	padding: 0;
}

@mixin resetList($display: block) {
	@include noOuterDimensions;
	display: $display;
	list-style: none;
}

@mixin roundedCorners($radius: 5px) {
	border-radius: $radius;
	-moz-border-radius: $radius;
	-webkit-border-radius: $radius;
	background-clip: padding-box;
	-moz-background-clip: padding-box;
	-webkit-background-clip: padding-box;
}

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

@mixin backgroundGradient($settings) {
	background-image: linear-gradient($settings);
	background-image: -o-linear-gradient($settings);
	background-image: -ms-linear-gradient($settings);
	background-image: -moz-linear-gradient($settings);
	background-image: -webkit-linear-gradient($settings);
}

@mixin opacity($value) {
	opacity: $value;
	filter: unquote("alpha(opacity=#{($value * 100)})");
}

@mixin transition($property: all, $time: .5s) {
	// transition times
	transition-duration: $time;
	-o-transition-duration: $time;
	-ms-transition-duration: $time;
	-moz-transition-duration: $time;
	-webkit-transition-duration: $time;
	// transition properties
	transition-property: $property;
	-o-transition-property: $property;
	-ms-transition-property: $property;
	-moz-transition-property: $property;
	-webkit-transition-property: $property;
	// transition function
	transition-timing-function: ease-in-out;
	-o-transition-timing-function: ease-in-out;
	-ms-transition-timing-function: ease-in-out;
	-moz-transition-timing-function: ease-in-out;
	-webkit-transition-timing-function: ease-in-out;
}

@mixin backgroundSize($tuplePercent) {
	background-size: $tuplePercent;
	-moz-background-size: $tuplePercent;
	-webkit-background-size: $tuplePercent;
}

UsingMixins.scss

//* scss-compile-options: :style => :compressed

// import global mixins
@import "Mixins.scss";

body {
	@include noOuterDimensions;
	/* unquote workaround for arbitrary number of parameters */
	@include backgroundGradient(unquote("#ccc, #fff 50%"));
}

ul.menu {
	@include resetList;
	li {
		@include resetList;
		float: left;
	}
}

input[type=text] {
	@include roundedCorners;
}

button {
	&:hover {
		@include shadow(0 1px 2px rgba(#000, .15));
	}
}

.someElement {
	@include opacity(.5);
	@include transition;
	&:hover {
		@include opacity(1);
	}
}