内容量に関わらず、常にフッターをページ下部に配置する方法

/* html */
 
<div class="wrapper">
	<div class="push"></div>
</div>
<div class="footer"></div>
 
 
 
/* CSS */
 
* {
	margin: 0;
}
html, body {
	height: 100%;
}
.wrapper {
	min-height: 100%;
	height: auto !important;
	height: 100%;
	margin: 0 auto -4em; /* the bottom margin is the negative value of the footer's height */
}
.footer, .push {
	height: 4em; /* .push must be the same height as .footer */
}