Introduction of presets across padding, margin and block gap – Make WordPress Core

The introduction of pre-set sizes to be shared across padding, margin and block gap in WordPress 6.1.

Gutenberg 13.2 Adds Persistent User Preferences and a Visualizer for Margin and Padding Controls – WP Tavern

What's New in WordPress 5.9 (Full Site Editing, Global Styles, APIs, and More)

Spacing – Theme Handbook

What's New in WordPress 6.2 - Kinsta®

Block Margins, Paddings & Block Gap (using theme.json)

WordPress Page Builder: Working with Padding and Margin

Theme.json layout and spacing options - Full Site Editing

Global Styles & theme.json - Full Site Editing

WordPress Spacing Explained - Padding/Margin/Border Usage In Elements

Extend theme.json to provide spacing size presets · Issue #39371 · WordPress/gutenberg · GitHub

Global Styles: Margins on the paragraph block · Issue #35267 · WordPress/gutenberg · GitHub