vant-weapp/packages/notice-bar/index.css

.van-notice-bar {
  display: flex;
  padding: 9px 10px;
  font-size: 12px;
  line-height: 1.5;

  &--within-icon {
    position: relative;
    padding-right: 30px;
  }

  &__left-icon {
    height: 18px;
    min-width: 20px;
    padding-top: 1px;
    box-sizing: border-box;

    > image {
      width: 16px;
      height: 16px;
    }
  }

  &__right-icon {
    position: absolute;
    top: 10px;
    right: 10px;
    font-size: 15px;
    line-height: 1;
  }

  &__content-wrap {
    position: relative;
    flex: 1;
    height: 18px;
    overflow: hidden;
  }

  &__content {
    position: absolute;
    white-space: nowrap;
  }
}