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HTML 

              
                <div id="root"></div>
!

CSS 

              
                body {
  padding: 2rem;
  font-family: -apple-system, BlinkMacSystemFont, "Helvetica Neue",
    "PingFang SC", "Microsoft YaHei", "Source Han Sans SC", "Noto Sans CJK SC",
    "WenQuanYi Micro Hei", sans-serif;
  font-size: 14px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

h2 {
  font-weight: 300;
}

.Demo {
  margin: 0 auto;
  max-width: 1010px;
}

.Demo .Mdi {
  background: rgba(0, 0, 0, .1);
}

.LineBox {
  position: relative;
  font-size: 100px;
  white-space: nowrap;
}

.LineBox .content {
  display: inline-block;
  width: 100%;
  margin-right: -100%;
  text-align: center;
}

.LineBox .line {
  position: relative;
  z-index: 2;
  display: inline-block;
  width: 100%;
  margin-right: -100%;
  border-top: 1px dashed;
  opacity: 0.5;
}

.LineBox .top {
  vertical-align: top;
  border-color: gray;
}

.LineBox .textTop {
  vertical-align: text-top;
  border-color: lightgray;
}

.LineBox .middle {
  vertical-align: middle;
  border-color: green;
}

.LineBox .baseline {
  vertical-align: baseline;
  border-color: red;
}

.LineBox .textBottom {
  vertical-align: text-bottom;
  border-color: lightgray;
}

.LineBox .bottom {
  vertical-align: bottom;
  border-color: gray;
}

.LineBox .cap {
  /* 假想的 cap line（平均高度），不一定准确（不同字体不同） */
  vertical-align: 0.7em;
  border-color: lightsteelblue;
}
!

JS 

              
                // Demo 4: strut hack
const ZWSP = '\u200b' /* ZWSP(zero-width space) */

const InlineBlockStrutHackIcon = ({size, width, height, ...props}) => (
  <span
    style={{
      position: 'relative',
      display: 'inline-block',
      lineHeight: size || height, // 使元素高度等于字体大小
      width: size || width, // 占住横向空间
    }}
  >
    {ZWSP}
    <Icons.Favorite
      width={size || width}
      height={size || height}
      style={{position: 'absolute', left: 0, top: 0}}
    />
  </span>
)

const InlineFlexStrutHackIcon = props => (
  <span
    style={{
      display: 'inline-flex',
      alignItems: 'center',
    }}
  >
    {ZWSP}
    <Icons.Favorite {...props} />
  </span>
)

const Demo = () => (
  <div className="Demo">
    <h2>inline-block + strut hack</h2>
    <LineBox>
      <InlineBlockStrutHackIcon size=".6em" />&nbsp;
      <InlineBlockStrutHackIcon size="1em" />&nbsp;
      <InlineBlockStrutHackIcon size="1.2em" />
      喜欢 Like
    </LineBox>

    <h2>inline-flex + strut hack</h2>
    <LineBox>
      <InlineFlexStrutHackIcon size=".6em" />&nbsp;
      <InlineFlexStrutHackIcon size="1em" />&nbsp;
      <InlineFlexStrutHackIcon size="1.2em" />
      喜欢 Like
    </LineBox>

    <h2>flex container without hacks</h2>
    <LineBox>
      <span
        style={{
          display: 'inline-flex',
          alignItems: 'center',
          verticalAlign: 'top',
        }}
      >
        <Icons.Favorite size=".6em" />&nbsp;
        <Icons.Favorite size="1em" />&nbsp;
        <Icons.Favorite size="1.2em" />
        喜欢 Like
      </span>
    </LineBox>
  </div>
)

const Debugger = ({size}) => (
  <span
    style={{
      display: 'inline-block',
      lineHeight: 1.2,
      background: 'lightsalmon',
    }}
  >
    i
  </span>
)

const LineBox = ({children, ...props}) => (
  <div draggable className="LineBox" {...props}>
    <span className="content">{children}</span>
    <span className="line top" />
    <span className="line textTop" />
    <span className="line cap" />
    <span className="line middle" />
    <span className="line baseline" />
    <span className="line textBottom" />
    <span className="line bottom" />
  </div>
)

// 完整封装见：http://ambar.li/reiconify/md.icons/
const Icon = ({size, ...props}) => (
  <svg {...props} {...size && {width: size, height: size}} />
)

Icon.defaultProps = {
  width: '1.2em',
  height: '1.2em',
  fill: 'currentColor',
  viewBox: '0 0 24 24',
}

const Icons = {
  AccessAlarm: props => (
    <Icon className="Mdi Mdi--AccessAlarm" {...props}>
      <path d="M22 5.72l-4.6-3.86-1.29 1.53 4.6 3.86L22 5.72zM7.88 3.39L6.6 1.86 2 5.71l1.29 1.53 4.59-3.85zM12.5 8H11v6l4.75 2.85.75-1.23-4-2.37V8zM12 4c-4.97 0-9 4.03-9 9s4.02 9 9 9a9 9 0 0 0 0-18zm0 16c-3.87 0-7-3.13-7-7s3.13-7 7-7 7 3.13 7 7-3.13 7-7 7z" />
    </Icon>
  ),

  Favorite: props => (
    <Icon className="Mdi Mdi--Favorite" {...props}>
      <path d="M12 21.35l-1.45-1.32C5.4 15.36 2 12.28 2 8.5 2 5.42 4.42 3 7.5 3c1.74 0 3.41.81 4.5 2.09C13.09 3.81 14.76 3 16.5 3 19.58 3 22 5.42 22 8.5c0 3.78-3.4 6.86-8.55 11.54L12 21.35z" />
    </Icon>
  ),

  Copyright: props => (
    <Icon className="Mdi Mdi--Copyright" {...props}>
      <path d="M10.08 10.86c.05-.33.16-.62.3-.87s.34-.46.59-.62c.24-.15.54-.22.91-.23.23.01.44.05.63.13.2.09.38.21.52.36s.25.33.34.53.13.42.14.64h1.79c-.02-.47-.11-.9-.28-1.29s-.4-.73-.7-1.01-.66-.5-1.08-.66-.88-.23-1.39-.23c-.65 0-1.22.11-1.7.34s-.88.53-1.2.92-.56.84-.71 1.36S8 11.29 8 11.87v.27c0 .58.08 1.12.23 1.64s.39.97.71 1.35.72.69 1.2.91 1.05.34 1.7.34c.47 0 .91-.08 1.32-.23s.77-.36 1.08-.63.56-.58.74-.94.29-.74.3-1.15h-1.79c-.01.21-.06.4-.15.58s-.21.33-.36.46-.32.23-.52.3c-.19.07-.39.09-.6.1-.36-.01-.66-.08-.89-.23-.25-.16-.45-.37-.59-.62s-.25-.55-.3-.88-.08-.67-.08-1v-.27c0-.35.03-.68.08-1.01zM12 2C6.48 2 2 6.48 2 12s4.48 10 10 10 10-4.48 10-10S17.52 2 12 2zm0 18c-4.41 0-8-3.59-8-8s3.59-8 8-8 8 3.59 8 8-3.59 8-8 8z" />
    </Icon>
  ),
}

ReactDOM.render(<Demo />, document.getElementById('root'))
!
999px

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