ul.post-attachments{list-style:none;margin:0;}
li.post-attachment{background:url(document.png) 0 4px no-repeat;padding-left:24px;}

/* Standard formats */
.post-attachment.mime-image-jpeg,.post-attachment.mime-image-png,.post-attachment.mime-image-gif{background-image:url(document-image.png);}
.post-attachment.mime-application-zip{background-image:url(document-zipper.png);}
.post-attachment.mime-application-pdf{background-image:url(document-pdf.png);}
.post-attachment.mime-audio-mpeg{background-image:url(document-music.png);}

/* Proprietary formats */
.post-attachment.mime-application-vnd-ms-excel,.post-attachment.mime-application-vnd-openxmlformats-officedocument-spreadsheetml-sheet{background-image:url(document-excel.png);}
.post-attachment.mime-application-msword,.post-attachment.mime-application-vnd-openxmlformats-officedocument-wordprocessingml-document{background-image:url(document-word.png);}

/* Open formats */
.post-attachment.mime-application-vnd-oasis-opendocument-spreadsheet{background-image:url(document-ods.png);}
.post-attachment.mime-application-vnd-oasis-opendocument-text{background-image:url(document-odt.png);}