message: use css suctom properties instead of hard-coded color values
diff: @@ -48,26 +48,26 @@ Not supports in Firefox and IE */
  /* total width */
  .CustomSelect__webkitScrollable::-webkit-scrollbar {
  - background-color: #fff;
  + background-color: var(--modal_card_background);
  width: 6px;
  }
  /* background of the scrollbar except button or resizer */
  .CustomSelect__webkitScrollable::-webkit-scrollbar-track {
  - background-color: #fff;
  + background-color: var(--modal_card_background);
  }
  /* scrollbar itself */
  .CustomSelect__webkitScrollable::-webkit-scrollbar-thumb {
  - background-color: #babac0;
  + background-color: var(--field_border);
  border-radius: 3px;
  - border: 1px solid #fff;
  + border: 1px solid var(--modal_card_background);
  min-height: 44px;
  }
  /* scrollbar itself */
  .CustomSelect__webkitScrollable:hover::-webkit-scrollbar-thumb {
  - background-color: #aaa;
  + background-color: var(--field_border_hover);
  }
  /* set button(top and bottom of the scrollbar) */
  