Using SASS for creating mediaqueries

gistfile1.scss

#content {
	background-color: #fff;
	clear: both;
	overflow: hidden;
	padding: 20px;
	@include breakpoint(600) {
		border: 2px solid $color1;
	}
}

	[role=main] {
		position: relative;
		@include breakpoint(720) {
			.two-col & {
				float: left;
				width: 720px;
			}
			.home & {
				width: 50%
			}
		}
	}

	[role=complementary] {
		box-sizing: border-box;
		@include breakpoint(720) {
			.two-col & {
				float: right;
				width: 200px;
			}
			.home & {
				padding-left: 40px;
				width: 50%;
			}
		}
	}

// Breakpoint mixin

$old-ie: false !default;

@mixin breakpoint($point) {
	@if $old-ie {
		@content;
	}
	@else {
		@media only screen and (min-width: $point / 16 * 1em) {
			@content;
		}
	}
}

// Main stylesheet

@charset "UTF-8";

@import 'master';

// Old IE stylesheet

@charset "UTF-8";

$old-ie: true;

@import 'master';