Horizontal overflow on blog post

[simevidas]

Example URL: https://openwebdocs.org/content/posts/secure-the-web-forward/

First, the embedded YouTube video causes the page to scroll horizontally on mobile devices. (I tested on iPhone SE.)

Second, the page footer has width: 100vw. At smaller page zoom factors (mine is 80%), the page overflows horizontally. Can you remove this declaration?