Perhaps the easiest is to use position: absolute
to fix to the bottom, then a suitable margin/padding to make sure that the other text doesn't spill over the top of it.
css:
<style>
body {
margin: 0 0 20px;
}
.footer {
position: absolute;
bottom: 0;
height: 20px;
background: #f0f0f0;
width: 100%;
}
</style>
Here is the html main content.
<div class="footer"> Here is the footer. </div>