Flip Card Clock
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Inspired by https://juejin.im/post/5dd9490a6fb9a07a961d11e7

A [Pen](https://codepen.io/alphardex/pen/vYYoBNR) by [alphardex](https://codepen.io/alphardex) on [CodePen](https://codepen.io).

[License](https://codepen.io/license/pen/vYYoBNR).