The introduction of pre-set sizes to be shared across padding, margin and block gap in WordPress 6.1.
Extend theme.json to provide spacing size presets · Issue #39371 · WordPress/gutenberg · GitHub
An Introduction to Spacing Presets - Builders
Using Presets – Theme Handbook
Theme.json layout and spacing options - Full Site Editing
WordPress6.1】theme.json の変更点 #WordPress - Qiita
Theme.json layout and spacing options - Full Site Editing
What's New in WordPress 6.2 - Kinsta®
How to Change Margins in WordPress for Better Web Design
Global Styles & theme.json - Full Site Editing