message: refactor: stepper use css var
diff: @import '@hi-ui/core-css/index.scss';
  +@import '../../core-css/index.scss';
  .hi-stepper {
  width: 100%;
  line-height: 24px;
  border-radius: 50%;
  text-align: center;
  - color: #fff;
  - background-color: #ccc;
  + color: use-color('white');
  + background-color: use-color('gray-50');
  }
  &__title {
  padding: 0 0 0 8px;
  - color: #999;
  + color: use-color('gray-80');
  text-align: center;
  word-break: keep-all;
  overflow: hidden;
  &__icon {
  display: inline-block;
  - background-color: #fff;
  + background-color: use-color('white');
  z-index: 1;
  text-align: center;
  width: 24px;
  align-items: center;
  min-width: 36px;
  padding: 0 8px;
  - background-color: #fff;
  + background-color: use-color('white');
  box-sizing: border-box;
  z-index: 1;
  }
  z-index: 1;
  display: flex;
  + &--active {
  + .hi-icon {
  + color: use-color('primary');
  + }
  +
  + .hi-stepper__num {
  + background-color: use-color('primary');
  + }
  +
  + .hi-stepper__title {
  + color: use-color('primary');
  + }
  + }
  +
  + &--done {
  + &::after {
  + background-color: use-color('primary') !important;
  + }
  + }
  +
  &::after {
  content: '';
  position: absolute;
  display: block;
  width: 100%;
  height: 1px;
  - background-color: #ccc;
  + background-color: use-color('gray-50');
  z-index: -1;
  }
  &__text {
  font-size: 12px;
  - color: #999;
  + color: use-color('gray-80');
  width: 100%;
  }
  }
  left: 12px;
  width: 1px;
  height: 100%;
  - background-color: #d8d8d8;
  }
  }
  &__icon {
  display: inline-block;
  padding: 4px 0;
  - background-color: #fff;
  + background-color: use-color('white');
  z-index: 1;
  }
  flex: 1 1 100%;
  margin-left: 32px;
  font-size: 12px;
  - color: #666;
  - }
  - }
  - }
  -}
  -
  -@each $key, $value in $palette-primary {
  - .theme__#{$key} {
  - .hi-stepper__item {
  - &--active {
  - .hi-icon {
  - color: map-get(get-palette($value), '50');
  - }
  -
  - .hi-stepper__num {
  - background-color: map-get(get-palette($value), '50');
  - }
  -
  - .hi-stepper__title {
  - color: map-get(get-palette($value), '50');
  - }
  - }
  -
  - &--done {
  - &::after {
  - background-color: map-get(get-palette($value), '50');
  - }
  + color: use-color('gray-80');
  }
  }
  }
  