Jak zmienić zmianę obrazu w CSS

<a href='foo.pdf'class='pdflink'>A File !</a>

/* .pdflink:after {
    content: url('/images/pdf.png')
} */

.pdflink:after {
    background-image: url('/images/pdf.png');
    background-size: 10px 20px;
    display: inline-block;
    width: 10px;
    height: 20px;
    content: "";
}
Simman