.social-network
{
    width: 100px;
    height: 20px;
    display: block;
}

.social-network ul
{
    list-style: none;
    height: 30px;
    display: inline-block;
    margin: 0;
    padding-left: 15px;
    padding-top: 5px;
}

.social-network ul li
{
    width: 20px;
    height: 20px;
    display: block;
    float: left;
    margin-right: 5px;
}

.social-network li.facebook a:link::before
{
    content:url('images/icone_facebook.png');
    width: 20px;
    height: 20px;
    display: block;
}

.social-network li.twitter a:link::before
{
    content:url('images/icone_twitter.png');
    width: 20px;
    height: 20px;
    display: block;
}