CSS: Stopka zawsze na samym dole strony

gistfile1

* {
	margin: 0;
}
html, body {
	height: 100%;
}
.wrapper {
	min-height: 100%;
	height: auto !important;
	height: 100%;
	margin: 0 auto -155px; /* the bottom margin is the negative value of the footer's height */
}
.footer, push {
	height: 155px; /* .push must be the same height as .footer */
}

<div class="wrapper">
    <div id="header">
        header - (menu, logo)
    </div>
    <div id="content">
        page content 
    </div>
    <div class="push"></div>
</div> 
<div class="footer">
    footer
</div>

flexbox version:

`html{
height: 100%;
}

body{
display: flex;
flex-direction: column;
height: 100%;
}

.main{
/* The main section will take up all the available free space
on the page that is not taken up by the footer. */
flex: 1 0 auto;
}

footer{
/* The footer will take up as much vertical space as it needs and not a pixel more. */
flex: 0 0 auto;
}`