How To Fix The White Bars In Safari On iPhone X

TL;DR: <meta name="viewport" content="width=device-width,initial-scale=1,viewport-fit=cover">

Thanks to Stephen Radford for his original posst: https://stephenradford.me/removing-the-white-bars-in-safari-on-iphone-x/

For me it was simply a case of adding viewport-fit=cover to my <meta name="viewport" content=".

Before:

After: