rtl.css

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Theme Name: Twenty Fourteen
Description: Adds support for languages written in a Right To Left (RTL) direction.
It’s easy, just a matter of overwriting all the horizontal positioning attributes
of your CSS stylesheet in a separate stylesheet file named rtl.css.
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–> https://codex.ww.wp.xz.cn/Right-to-Left_Language_Support

There is not enough information in the article at the end on what to do next.