Describe the bug

Full-width Text on Media or Text with Background paragraphs in the Content region fully cover the width of the page. In contrast, full-width paragraphs in other regions include a right margin of 15px for the scrollbar.

This extra right margin is confirmed to appear on:

• macOS, all browsers, with the "Show scroll bars" setting as "Automatically based on mouse or trackpad" or "Always". If that setting is set to "When scrolling", this issue does not appear.
• Windows 10, Chrome browser

This extra right margin is confirmed NOT to appear on:

• macOS, all browsers, with the "Show scroll bars" setting as "When scrolling"
• Android 9, Chrome browser

To Reproduce

Steps to reproduce the behavior:

1. Create a page with a full-width Text on Media paragraph.
2. Create a block with another full-width Text on Media paragraph.
3. In Block Layout, add the block to a region such as Content Top or Full Width Content Bottom.
4. Observe that the widths of the two paragraphs are not the same.

Proposed resolution

Either:

1. Add the right margin for the scrollbar to full-width paragraphs in the Content region, or
2. Remove the right margin for the scrollbar from full-width paragraphs in all other regions

Expected behavior

Full-width paragraphs should have a consistent width across all regions.