介绍下重绘和回流（Repaint & Reflow），以及如何进行优化

https://github.com/Advanced-Frontend/Daily-Interview-Question/issues/24

https://www.cnblogs.com/yuer20180726/p/11165461.html

https://blog.csdn.net/u014744118/article/details/80699537

https://blog.csdn.net/weixin_34353714/article/details/91445129

https://blog.csdn.net/vM199zkg3Y7150u5/article/details/85042996