.file-icon {
    display: block;
    float: left;
    width: 32px;
    height: 32px;
    background-repeat: no-repeat;
    -webkit-background-size: contain;
    background-size: contain;
    margin: 0px 3px;
}
.icon-doc {
    background: url('/file_icons/doc.png');
}
.icon-pdf {
    background: url('/file_icons/pdf.png');
}
.icon-ppt {
    background: url('/file_icons/ppt.png');
}
.icon-txt {
    background: url('/file_icons/txt.png');
}
.icon-xls {
    background: url('/file_icons/xls.png');
}
.icon-zip {
    background: url('/file_icons/zip.png');
}