.tablesorter-header{
  cursor:pointer;
  white-space: nowrap;
}
.tablesorter-header span::after {
  content: '↕';
  /* font-family: Arial, sans-serif; */
  display:inline-block;
  padding-left:5px;
}
.tablesorter-headerAsc span::after {
  content: '↑';
}
.tablesorter-headerDesc span::after {
  content: '↓';
}