Quick summary

On some themes like Publication and Shoreditch the full and wide alignment moves the content almost completely off the screen

Steps to reproduce

1. Create a page.
2. Add a pattern like the ones in About:
3. Make sure it's set to full or wide width

A clear and concise description of what you expected to happen.

For the content to remain withing the browser viewport.

What actually happened

It went rogue in full width:

In wide it moves it more to the center, but it's still off the screen:

Impact

Some (< 50%)

Available workarounds?

Yes, easy to implement

If the above answer is "Yes...", outline the workaround.

The workaround is to avoid the full/wide alignment options or consider CSS.

Platform (Simple and/or Atomic)

Simple

Logs or notes

I only tested on Simple sites using Publication(reported by the user) and Shoreditch(as a second guess), but I have a hunch all classic themes that don't have a boxed layout have the same issue. Unfortunately, I don't know how to locate these in one go.

Reported here: https://wordpress.com/forums/topic/all-content-in-editor-shifts-far-to-the-left-in-preview/

cc @dsas