See demo on Codepen: https://codepen.io/comehope/pen/MqpOdR/
Watch interactive video on Scrimba: https://scrimba.com/p/pEgDAM/czZnbsr
Read annotated source on Segmentfault(zh-cn): https://segmentfault.com/a/1190000016243834
Inspired by: Mert Nerukuc https://codepen.io/knyttneve/pen/yqwXyM