Error font-family for Simplified Chinese (zh_CN) in twentyseventeen’s CSS

In the style.css of the new theme twentyseventeen (both stable and nightly build), line 664, which defines Chinese font:

/* Typography for Chinese Font */

html[lang^="zh-"] body,
html[lang^="zh-"] button,
html[lang^="zh-"] input,
html[lang^="zh-"] select,
html[lang^="zh-"] textarea {
	font-family: "PingFang TC", "Helvetica Neue", Helvetica, STHeitiTC-Light, Arial, sans-serif;
}

However, this CSS is only suitable for zh-HK and zh-TW, but not for zh-CN, which should not use traditional Chinese (TC), but Simplified Chinese (SC)

So it needs to add these line after that, and it works well:

html[lang="zh-CN"] body,
html[lang="zh-CN"] button,
html[lang="zh-CN"] input,
html[lang="zh-CN"] select,
html[lang="zh-CN"] textarea {
    font-family: "PingFang SC", "Helvetica Neue", Helvetica, STHeitiSC-Light, Arial, sans-serif
}