message: refactor: breadcrumb use css var
diff: &__separator {
  margin: 0 8px;
  - color: #ccc;
  + color: use-color('gray-30');
  }
  &__item {
  display: inline-block;
  a {
  - color: #666;
  + color: use-color('gray-80');
  }
  .hi-breadcrumb__content:hover {
  &__item:last-child {
  .hi-breadcrumb__content {
  cursor: text;
  - color: #666;
  + color: use-color('gray-80');
  }
  .hi-breadcrumb__separator {
  