.media a.file{display:block;width:48px;height:48px;text-indent:-9999px;overflow:hidden;background:url(actions.png);}

/* Images */
.media a.file.mime-image{background-position:-48px center;}

/* Text */
.media a.file.mime-text{background-position:-96px center;}

/* Video */
.media a.file.mime-video{background-position:-144px center;}

/* Extensões específicas */
.media a.file.mime-pdf{background-position:-192px center;}
.media a.file.mime-msword{background-position:-240px center;}