See demo on Codepen: https://codepen.io/comehope/pen/qKmGaJ
Watch interactive video on Scrimba: https://scrimba.com/p/pEgDAM/cPpkyUK
Read annotated source on Segmentfault(zh-cn): https://segmentfault.com/a/1190000015270808
Inspired by: Wagner Moschini https://codepen.io/wagnermoschini/pen/RxooKO