.file-icon {
  display: inline-block;
  padding-left: 25px;
  background-image: url('../images/pdf.png');
  background-position: 0 50%;
  background-repeat:no-repeat;
  background-size: 18px;
}
a[href$=".pdf"].file-icon {
  background-image: url('../images/pdf.png');
}
a[href$=".doc"].file-icon,
a[href$=".docx"].file-icon {
  background-image: url('../images/doc.png');
}
a[href$=".xls"].file-icon,
a[href$=".xlsx"].file-icon {
  background-image: url('../images/xls.png');
}
a[href$=".ppt"].file-icon,
a[href$=".pptx"].file-icon {
  background-image: url('../images/ppt.png');
}

a.file-icon.no-file-icon {
  padding-left: 0;
  background: none;
}