I create footer with footer tag `<footer>` , but my problem is I can't to change background color

Here is a code:

HTML:

```
<footer class="site-footer">

<div id="footer1"><p>Copyright  2013 Domain Name - All Rights Reserved </p></div>
<div id="footer2"><p> Template by OS Templates </p></div>

</footer>

```

CSS:

```
.site-footer {
  background: orange;
}

#footer1{
margin-left:2%;
float:left;

}
#footer2{
margin-right:2%;
float:right;
}

```