Index: /trunk/src/wp-includes/class-wp-theme-json.php
===================================================================
--- /trunk/src/wp-includes/class-wp-theme-json.php	(revision 58443)
+++ /trunk/src/wp-includes/class-wp-theme-json.php	(revision 58444)
@@ -2901,8 +2901,8 @@
 			// Alignfull children of the container with left and right padding have negative margins so they can still be full width.
 			$css .= '.has-global-padding > .alignfull { margin-right: calc(var(--wp--style--root--padding-right) * -1); margin-left: calc(var(--wp--style--root--padding-left) * -1); }';
-			// Nested children of the container with left and right padding that are not wide or full aligned do not get padding.
-			$css .= '.has-global-padding :where(.has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) { padding-right: 0; padding-left: 0; }';
-			// Nested children of the container with left and right padding that are not wide or full aligned do not get negative margin applied.
-			$css .= '.has-global-padding :where(.has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) > .alignfull { margin-left: 0; margin-right: 0; }';
+			// Nested children of the container with left and right padding that are not wide or full aligned do not get padding, unless they are direct children of an alignfull flow container.
+			$css .= '.has-global-padding :where(:not(.alignfull.is-layout-flow) > .has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) { padding-right: 0; padding-left: 0; }';
+			// Alignfull direct children of the containers that are targeted by the rule above do not need negative margins.
+			$css .= '.has-global-padding :where(:not(.alignfull.is-layout-flow) > .has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) > .alignfull { margin-left: 0; margin-right: 0; }';
 		}
 
Index: /trunk/tests/phpunit/tests/theme/wpThemeJson.php
===================================================================
--- /trunk/tests/phpunit/tests/theme/wpThemeJson.php	(revision 58443)
+++ /trunk/tests/phpunit/tests/theme/wpThemeJson.php	(revision 58444)
@@ -3747,5 +3747,5 @@
 		);
 
-		$expected    = ':where(body) { margin: 0; }.wp-site-blocks { padding-top: var(--wp--style--root--padding-top); padding-bottom: var(--wp--style--root--padding-bottom); }.has-global-padding { padding-right: var(--wp--style--root--padding-right); padding-left: var(--wp--style--root--padding-left); }.has-global-padding > .alignfull { margin-right: calc(var(--wp--style--root--padding-right) * -1); margin-left: calc(var(--wp--style--root--padding-left) * -1); }.has-global-padding :where(.has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) { padding-right: 0; padding-left: 0; }.has-global-padding :where(.has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) > .alignfull { margin-left: 0; margin-right: 0; }.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }.wp-site-blocks > .alignright { float: right; margin-left: 2em; }.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }:where(.is-layout-flex){gap: 0.5em;}:where(.is-layout-grid){gap: 0.5em;}.is-layout-flow > .alignleft{float: left;margin-inline-start: 0;margin-inline-end: 2em;}.is-layout-flow > .alignright{float: right;margin-inline-start: 2em;margin-inline-end: 0;}.is-layout-flow > .aligncenter{margin-left: auto !important;margin-right: auto !important;}.is-layout-constrained > .alignleft{float: left;margin-inline-start: 0;margin-inline-end: 2em;}.is-layout-constrained > .alignright{float: right;margin-inline-start: 2em;margin-inline-end: 0;}.is-layout-constrained > .aligncenter{margin-left: auto !important;margin-right: auto !important;}.is-layout-constrained > :where(:not(.alignleft):not(.alignright):not(.alignfull)){margin-left: auto !important;margin-right: auto !important;}body .is-layout-flex{display: flex;}.is-layout-flex{flex-wrap: wrap;align-items: center;}.is-layout-flex > :is(*, div){margin: 0;}body .is-layout-grid{display: grid;}.is-layout-grid > :is(*, div){margin: 0;}:root :where(body){--wp--style--root--padding-top: 10px;--wp--style--root--padding-right: 12px;--wp--style--root--padding-bottom: 10px;--wp--style--root--padding-left: 12px;}';
+		$expected    = ':where(body) { margin: 0; }.wp-site-blocks { padding-top: var(--wp--style--root--padding-top); padding-bottom: var(--wp--style--root--padding-bottom); }.has-global-padding { padding-right: var(--wp--style--root--padding-right); padding-left: var(--wp--style--root--padding-left); }.has-global-padding > .alignfull { margin-right: calc(var(--wp--style--root--padding-right) * -1); margin-left: calc(var(--wp--style--root--padding-left) * -1); }.has-global-padding :where(:not(.alignfull.is-layout-flow) > .has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) { padding-right: 0; padding-left: 0; }.has-global-padding :where(:not(.alignfull.is-layout-flow) > .has-global-padding:not(.wp-block-block, .alignfull, .alignwide)) > .alignfull { margin-left: 0; margin-right: 0; }.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }.wp-site-blocks > .alignright { float: right; margin-left: 2em; }.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }:where(.is-layout-flex){gap: 0.5em;}:where(.is-layout-grid){gap: 0.5em;}.is-layout-flow > .alignleft{float: left;margin-inline-start: 0;margin-inline-end: 2em;}.is-layout-flow > .alignright{float: right;margin-inline-start: 2em;margin-inline-end: 0;}.is-layout-flow > .aligncenter{margin-left: auto !important;margin-right: auto !important;}.is-layout-constrained > .alignleft{float: left;margin-inline-start: 0;margin-inline-end: 2em;}.is-layout-constrained > .alignright{float: right;margin-inline-start: 2em;margin-inline-end: 0;}.is-layout-constrained > .aligncenter{margin-left: auto !important;margin-right: auto !important;}.is-layout-constrained > :where(:not(.alignleft):not(.alignright):not(.alignfull)){margin-left: auto !important;margin-right: auto !important;}body .is-layout-flex{display: flex;}.is-layout-flex{flex-wrap: wrap;align-items: center;}.is-layout-flex > :is(*, div){margin: 0;}body .is-layout-grid{display: grid;}.is-layout-grid > :is(*, div){margin: 0;}:root :where(body){--wp--style--root--padding-top: 10px;--wp--style--root--padding-right: 12px;--wp--style--root--padding-bottom: 10px;--wp--style--root--padding-left: 12px;}';
 		$root_rules  = $theme_json->get_root_layout_rules( WP_Theme_JSON::ROOT_BLOCK_SELECTOR, $metadata );
 		$style_rules = $theme_json->get_styles_for_block( $metadata );
