tr:hover {
  background-color: #f8f9fa !important;
}

td {
  border-bottom-color: #bbb !important;
}

.nested_td {
  padding: 0 !important;
  tr:hover {
    background-color: transparent !important;
  }
  td {
    border: none !important;
    border-bottom: 1px solid #e6e6e6 !important;
  }
  tr:last-child td {
    border-bottom: none !important;
  }
}