message: use shorthand styles
diff: }
  .CalendarDay--selection-start.CalendarDay--selected {
  - border-bottom-left-radius: 8px;
  - border-top-left-radius: 8px;
  - border-bottom-right-radius: 0;
  - border-top-right-radius: 0;
  + border-radius: 8px 0 0 8px;
  }
  .CalendarDay--selection-end.CalendarDay--selected {
  - border-bottom-left-radius: 0;
  - border-top-left-radius: 0;
  - border-bottom-right-radius: 8px;
  - border-top-right-radius: 8px;
  + border-radius: 0 8px 8px 0;
  }
  .CalendarDay__hidden {
  