弹幕滚动

自己初步想的将窗口屏幕分成几个DIV，然后随机显示

但是我遇到了一个问题

为什么我的button 执行函数后，并不现实滚动字幕？

https://codepen.io/rennysky/full/QVwQeg/

Start with the linked CodePen and reproduce the button action that should display scrolling captions. Inspect the button handler and the resulting DOM or browser console to identify why the scrolling text is not shown. Done means the button reliably displays the intended scrolling captions.

Written by the indexing model from the issue text.