.pdf {
  width:20px;
  padding: 3px 20px 2px 0;
  background: url(images/pdf.png) no-repeat right;
  }
  
.zip {
  width:20px;
  padding: 3px 20px 2px 0;
  background: url(images/zip.png) no-repeat right;
  }
  
.doc {
  width:20px;
  padding: 3px 20px 2px 0;
  background: url(images/doc.png) no-repeat right;
  }
  
.ppt {
  width:20px;
  padding: 3px 20px 2px 0;
  background: url(images/ppt.png) no-repeat right;
  }
  
.txt {
  width:20px;
  padding: 3px 20px 2px 0;
  background: url(images/txt.png) no-repeat right;
  }
  
.xls {
  width:20px;
  padding: 3px 20px 2px 0;
  background: url(images/xls.png) no-repeat right;
  }