begin code

index.html

<div id="wrap">
		<header style="background: blue;">
			<div class="container">
				header 
			</div>	
		</header>
		<section style="background: green;">
			<div class="container">
				content
			</div>
		</section>	
		<!-- Прижимаем футер к низу -->
		<div id="push"></div>
	</div>
	<footer id="footer" style="background: grey;">
		<div class="container">
		footer 
		</div>
	</footer>