CSS

css overflow-y

#elem_tag{height:400px;overflow-y:auto} /*Give it a height and overflow*/

overflow-y scroll css

::-webkit-scrollbar {
  height: 12px;
  width: 12px;
  background: #fff;
}

::-webkit-scrollbar-thumb {
  background: #f27f3d;
  -webkit-border-radius: 1ex;
}

::-webkit-scrollbar-corner {
  background: #000;
}