综合了 google 对于 reflow 的优化实践和 stubbornella.org 上对于 reflow 和 repaint 讲解，力求一目了然的效果。
The more deeply you force your brain to think, the better chance you have of learning and remembering.
Only 10–20% of the end user response time is spent downloading the HTML document. The other 80–90% is spent downloading all the components in the page..
If it’s short, it’s more likely to actually be used
（转载请署名，优化总结这些代码和知识点消耗 RayJune 大量元气）
Collect some RegExp concepts and demos from MDN.
(Some of these demos modified by myself).