// Author: Sivan [sun.sivan@gmail.com]
// Description: heading styles.
@import "variables";

@mixin hetiHeading {
  h1,
  h2,
  h3,
  h4,
  h5,
  h6 {
    position: relative;

    // 顶边距默认为一行间距，且不因边距重叠原因减半
    // 底边距考虑到亲密性，默认为半行间距
    margin: 0;
    margin-block-start: $std-block-unit;
    margin-block-end: $std-block-unit * 0.5;
    font-weight: $font-weight-bold;
  }

  h1 {
    margin-block-end: $std-block-unit;
    font-size: $font-size-h1;
    line-height: $line-height-size-h1;
  }

  h2 {
    font-size: $font-size-h2;
    line-height: $line-height-size-h2;
  }

  h3 {
    font-size: $font-size-h3;
    line-height: $line-height-size-h3;
  }

  h4 {
    font-size: $font-size-h4;
    line-height: $line-height-size-h4;
  }

  h5 {
    font-size: $font-size-h5;
    line-height: $line-height-size-h5;
  }

  h6 {
    font-size: $font-size-h6;
    line-height: $line-height-size-h6;
  }

  h1,
  h2,
  h3 {
    // 中文大标题增加微小文字间距
    letter-spacing: 0.05em;

    // 非中文时不加间距
    @include non-cjk-block {
      letter-spacing: 0;
    }
  }

  // 压缩两个标题之间的间距
  h1 + h2,
  h2 + h3,
  h3 + h4,
  h4 + h5,
  h5 + h6 {
    margin-block-start: $std-block-unit * 0.5;
  }
}