Here is my pen. I having problems on mobile browsers. There is flickering when scroll. Black menu button and its click animation is important for me. That is why I used .allsitecontent div. If problem occurs because of this div I can change my menu scenario. But if I can make it with container div, it is best for me.
Another problem is : If I scroll fast when orange section reached top of the viewport, happening kind of jump towards to bottom. This jumping problem occurs only android devices chrome browser. My device OS is : Android 11.0 and Chrome version is : 88.04324.181
I have also have ios and android 8.0 devices for testing. There is no problem. But flickering happening on all mobile browsers.
Thanks all..