message: refactor: tooltip use css var
diff: +@import '../../core-css/index.scss';
  +
  .hi-tooltip {
  position: relative;
  display: inline-block;
  .hi-tooltip-base {
  border-radius: 2px;
  - background: #333;
  - font-size: 12px;
  - color: #fff;
  + background: use-color('gray-80');
  + font-size: $font-size-small;
  + color: use-color('white');
  padding: 6px 12px;
  line-height: 20px;
  white-space: nowrap;
  position: absolute;
  width: 5px;
  height: 5px;
  - background: #333;
  + background: use-color('gray-80');
  }
  }
  