.my_class_name{
  column-count: 3;
  column-width: 100px;
  column-gap: 20px;
  
  column-rule: 1px solid #ccc;
}

Feel free to comment if you can add help to this page or point out issues and solutions you have found. I do not provide support on this site, if you need help with a problem head over to stack overflow.