diff --git a/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php b/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php
index 82232aaf4121f..b98885a944c72 100644
--- a/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php
+++ b/lib/compat/wordpress-6.1/class-wp-theme-json-6-1.php
@@ -430,6 +430,113 @@ protected static function get_blocks_metadata() {
 		return static::$blocks_metadata;
 	}
 
+	/**
+	 * Returns a WP_Style_Engine_CSS_Rules_Store_Gutenberg object for the given nodes.
+	 *
+	 * @since 6.1.0
+	 *
+	 * @param array $setting_nodes Nodes with settings.
+	 * @param array $origins       List of origins to process presets from.
+	 *
+	 * @return WP_Style_Engine_CSS_Rules_Store_Gutenberg
+	 */
+	protected function get_preset_classes_store( $setting_nodes, $origins ) {
+		$store = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_store( 'global-styles/preset-classes' );
+
+		foreach ( $setting_nodes as $metadata ) {
+			if ( null === $metadata['selector'] ) {
+				continue;
+			}
+
+			$selector = $metadata['selector'];
+			$node     = _wp_array_get( $this->theme_json, $metadata['path'], array() );
+			$store->add_store( static::compute_preset_classes_store( $node, $selector, $origins ) );
+		}
+		return $store;
+	}
+
+	/**
+	 * Creates new rulesets as classes for each preset value such as:
+	 *
+	 *   .has-value-color {
+	 *     color: value;
+	 *   }
+	 *
+	 *   .has-value-background-color {
+	 *     background-color: value;
+	 *   }
+	 *
+	 *   .has-value-font-size {
+	 *     font-size: value;
+	 *   }
+	 *
+	 *   .has-value-gradient-background {
+	 *     background: value;
+	 *   }
+	 *
+	 *   p.has-value-gradient-background {
+	 *     background: value;
+	 *   }
+	 *
+	 * @since 5.9.0
+	 *
+	 * @param array $setting_nodes Nodes with settings.
+	 * @param array $origins       List of origins to process presets from.
+	 * @return string The new stylesheet.
+	 */
+	protected function get_preset_classes( $setting_nodes, $origins ) {
+		return ( new WP_Style_Engine_Processor_Gutenberg( $this->get_preset_classes_store( $setting_nodes, $origins ) ) )->get_css();
+	}
+
+	/**
+	 * Returns a WP_Style_Engine_CSS_Rules_Store_Gutenberg object for the given nodes.
+	 *
+	 * @since 6.1.0
+	 *
+	 * @param array $nodes   Nodes with settings.
+	 * @param array $origins List of origins to process.
+	 *
+	 * @return WP_Style_Engine_CSS_Rules_Store_Gutenberg
+	 */
+	protected function get_css_variables_store( $nodes, $origins ) {
+		$store = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_store( 'global-styles/css-variables' );
+		foreach ( $nodes as $metadata ) {
+			if ( null === $metadata['selector'] ) {
+				continue;
+			}
+
+			$node         = _wp_array_get( $this->theme_json, $metadata['path'], array() );
+			$declarations = array_merge( static::compute_preset_vars( $node, $origins ), static::compute_theme_vars( $node ) );
+			$store->add_rule( $metadata['selector'] )->add_declarations( $this->get_plain_declarations_from_pairs( $declarations ) );
+		}
+		return $store;
+	}
+
+	/**
+	 * Converts each styles section into a list of rulesets
+	 * to be appended to the stylesheet.
+	 * These rulesets contain all the css variables (custom variables and preset variables).
+	 *
+	 * See glossary at https://developer.mozilla.org/en-US/docs/Web/CSS/Syntax
+	 *
+	 * For each section this creates a new ruleset such as:
+	 *
+	 *     block-selector {
+	 *       --wp--preset--category--slug: value;
+	 *       --wp--custom--variable: value;
+	 *     }
+	 *
+	 * @since 5.8.0
+	 * @since 5.9.0 Added the `$origins` parameter.
+	 *
+	 * @param array $nodes   Nodes with settings.
+	 * @param array $origins List of origins to process.
+	 * @return string The new stylesheet.
+	 */
+	protected function get_css_variables( $nodes, $origins ) {
+		return ( new WP_Style_Engine_Processor_Gutenberg( $this->get_css_variables_store( $nodes, $origins ) ) )->get_css();
+	}
+
 	/**
 	 * Builds metadata for the style nodes, which returns in the form of:
 	 *
@@ -581,17 +688,19 @@ private static function get_block_nodes( $theme_json, $selectors = array() ) {
 	}
 
 	/**
-	 * Returns the stylesheet that results of processing
-	 * the theme.json structure this object represents.
+	 * Returns a WP_Style_Engine_CSS_Rules_Store_Gutenberg object for the given types and origins.
+	 *
+	 * @since 6.1.0
 	 *
 	 * @param array $types    Types of styles to load. Will load all by default. It accepts:
 	 *                         'variables': only the CSS Custom Properties for presets & custom ones.
 	 *                         'styles': only the styles section in theme.json.
 	 *                         'presets': only the classes for the presets.
 	 * @param array $origins A list of origins to include. By default it includes VALID_ORIGINS.
-	 * @return string Stylesheet.
+	 * @return WP_Style_Engine_CSS_Rules_Store_Gutenberg
 	 */
-	public function get_stylesheet( $types = array( 'variables', 'styles', 'presets' ), $origins = null ) {
+	public function get_stylesheet_store( $types = array( 'variables', 'styles', 'presets' ), $origins = null ) {
+		$store = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_store( 'global-styles' );
 		if ( null === $origins ) {
 			$origins = static::VALID_ORIGINS;
 		}
@@ -612,14 +721,11 @@ public function get_stylesheet( $types = array( 'variables', 'styles', 'presets'
 		$style_nodes     = static::get_style_nodes( $this->theme_json, $blocks_metadata );
 		$setting_nodes   = static::get_setting_nodes( $this->theme_json, $blocks_metadata );
 
-		$stylesheet = '';
-
 		if ( in_array( 'variables', $types, true ) ) {
-			$stylesheet .= $this->get_css_variables( $setting_nodes, $origins );
+			$store->add_store( $this->get_css_variables_store( $setting_nodes, $origins ) );
 		}
-
 		if ( in_array( 'styles', $types, true ) ) {
-			$stylesheet .= $this->get_block_classes( $style_nodes );
+			$store->add_store( $this->get_block_classes_store( $style_nodes ) );
 		} elseif ( in_array( 'base-layout-styles', $types, true ) ) {
 			// Base layout styles are provided as part of `styles`, so only output separately if explicitly requested.
 			// For backwards compatibility, the Columns block is explicitly included, to support a different default gap value.
@@ -636,25 +742,41 @@ public function get_stylesheet( $types = array( 'variables', 'styles', 'presets'
 			);
 
 			foreach ( $base_styles_nodes as $base_style_node ) {
-				$stylesheet .= $this->get_layout_styles( $base_style_node );
+				$store->add_store( $this->get_layout_styles_store( $base_style_node ) );
 			}
 		}
 
 		if ( in_array( 'presets', $types, true ) ) {
-			$stylesheet .= $this->get_preset_classes( $setting_nodes, $origins );
+			$store->add_store( $this->get_preset_classes_store( $setting_nodes, $origins ) );
 		}
 
-		return $stylesheet;
+		return $store;
 	}
 
 	/**
-	 * Gets the CSS rules for a particular block from theme.json.
+	 * Returns the stylesheet that results of processing
+	 * the theme.json structure this object represents.
+	 *
+	 * @param array $types    Types of styles to load. Will load all by default. It accepts:
+	 *                         'variables': only the CSS Custom Properties for presets & custom ones.
+	 *                         'styles': only the styles section in theme.json.
+	 *                         'presets': only the classes for the presets.
+	 * @param array $origins A list of origins to include. By default it includes VALID_ORIGINS.
+	 * @return string Stylesheet.
+	 */
+	public function get_stylesheet( $types = array( 'variables', 'styles', 'presets' ), $origins = null ) {
+		return ( new WP_Style_Engine_Processor_Gutenberg( $this->get_stylesheet_store( $types, $origins ) ) )->get_css();
+	}
+
+	/**
+	 * Returns a WP_Style_Engine_CSS_Rules_Store_Gutenberg object for the given block metadata.
 	 *
 	 * @param array $block_metadata Metadata about the block to get styles for.
 	 *
-	 * @return string Styles for the block.
+	 * @return WP_Style_Engine_CSS_Rules_Store_Gutenberg
 	 */
-	public function get_styles_for_block( $block_metadata ) {
+	public function get_block_styles_store( $block_metadata ) {
+		$store            = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_store( 'global-styles/blocks' );
 		$node             = _wp_array_get( $this->theme_json, $block_metadata['path'], array() );
 		$use_root_padding = isset( $this->theme_json['settings']['useRootPaddingAwareAlignments'] ) && true === $this->theme_json['settings']['useRootPaddingAwareAlignments'];
 		$selector         = $block_metadata['selector'];
@@ -723,8 +845,6 @@ function( $pseudo_selector ) use ( $selector ) {
 			$declarations = static::compute_style_properties( $node, $settings, null, $this->theme_json, $selector, $use_root_padding );
 		}
 
-		$block_rules = '';
-
 		// 1. Separate the ones who use the general selector
 		// and the ones who use the duotone selector.
 		$declarations_duotone = array();
@@ -744,16 +864,16 @@ function( $pseudo_selector ) use ( $selector ) {
 		 * @link https://github.com/WordPress/gutenberg/issues/36147.
 		 */
 		if ( static::ROOT_BLOCK_SELECTOR === $selector ) {
-			$block_rules .= 'body { margin: 0; }';
+			$store->add_rule( 'body' )->add_declarations( array( 'margin' => '0' ) );
 		}
 
 		// 2. Generate and append the rules that use the general selector.
-		$block_rules .= static::to_ruleset( $selector, $declarations );
+		$store->add_rule( $selector )->add_declarations( $this->get_plain_declarations_from_pairs( $declarations ) );
 
 		// 3. Generate and append the rules that use the duotone selector.
 		if ( isset( $block_metadata['duotone'] ) && ! empty( $declarations_duotone ) ) {
 			$selector_duotone = static::scope_selector( $block_metadata['selector'], $block_metadata['duotone'] );
-			$block_rules     .= static::to_ruleset( $selector_duotone, $declarations_duotone );
+			$store->add_rule( $selector_duotone )->add_declarations( $this->get_plain_declarations_from_pairs( $declarations_duotone ) );
 		}
 
 		// 4. Generate Layout block gap styles.
@@ -761,39 +881,110 @@ function( $pseudo_selector ) use ( $selector ) {
 			static::ROOT_BLOCK_SELECTOR !== $selector &&
 			! empty( $block_metadata['name'] )
 		) {
-			$block_rules .= $this->get_layout_styles( $block_metadata );
+			$store->add_store( $this->get_layout_styles_store( $block_metadata ) );
 		}
 
 		// 5. Generate and append the feature level rulesets.
 		foreach ( $feature_declarations as $feature_selector => $individual_feature_declarations ) {
-			$block_rules .= static::to_ruleset( $feature_selector, $individual_feature_declarations );
+			$store->add_rule( $feature_selector )->add_declarations( $this->get_plain_declarations_from_pairs( $individual_feature_declarations ) );
 		}
 
 		if ( static::ROOT_BLOCK_SELECTOR === $selector ) {
 			$block_gap_value = _wp_array_get( $this->theme_json, array( 'styles', 'spacing', 'blockGap' ), '0.5em' );
 
 			if ( $use_root_padding ) {
-				$block_rules .= '.wp-site-blocks { padding-top: var(--wp--style--root--padding-top); padding-bottom: var(--wp--style--root--padding-bottom); }';
-				$block_rules .= '.has-global-padding { padding-right: var(--wp--style--root--padding-right); padding-left: var(--wp--style--root--padding-left); }';
-				$block_rules .= '.has-global-padding > .alignfull { margin-right: calc(var(--wp--style--root--padding-right) * -1); margin-left: calc(var(--wp--style--root--padding-left) * -1); }';
-				$block_rules .= '.has-global-padding > .alignfull > :where([class*="wp-block-"]:not(.alignfull):not(.alignfull):not([class*="__"]),p,h1,h2,h3,h4,h5,h6,ul,ol) { padding-right: var(--wp--style--root--padding-right); padding-left: var(--wp--style--root--padding-left); }';
+				$store->add_rule( '.wp-site-blocks' )->add_declarations(
+					array(
+						'padding-top'    => 'var(--wp--style--root--padding-top)',
+						'padding-bottom' => 'var(--wp--style--root--padding-bottom)',
+					)
+				);
+				$store->add_rule( '.has-global-padding' )->add_declarations(
+					array(
+						'padding-right' => 'var(--wp--style--root--padding-right)',
+						'padding-left'  => 'var(--wp--style--root--padding-left)',
+					)
+				);
+				$store->add_rule( '.has-global-padding > .alignfull' )->add_declarations(
+					array(
+						'margin-right' => 'calc(var(--wp--style--root--padding-right) * -1)',
+						'margin-left'  => 'calc(var(--wp--style--root--padding-left) * -1)',
+					)
+				);
+				$store->add_rule( '.has-global-padding > .alignfull > :where([class*="wp-block-"]:not(.alignfull):not(.alignfull):not([class*="__"]),p,h1,h2,h3,h4,h5,h6,ul,ol)' )->add_declarations(
+					array(
+						'padding-right' => 'var(--wp--style--root--padding-right)',
+						'padding-left'  => 'var(--wp--style--root--padding-left)',
+					)
+				);
 			}
 
-			$block_rules .= '.wp-site-blocks > .alignleft { float: left; margin-right: 2em; }';
-			$block_rules .= '.wp-site-blocks > .alignright { float: right; margin-left: 2em; }';
-			$block_rules .= '.wp-site-blocks > .aligncenter { justify-content: center; margin-left: auto; margin-right: auto; }';
+			$store->add_rule( '.wp-site-blocks > .alignleft' )->add_declarations(
+				array(
+					'float'        => 'left',
+					'margin-right' => '2em',
+				)
+			);
+			$store->add_rule( '.wp-site-blocks > .alignright' )->add_declarations(
+				array(
+					'float'       => 'right',
+					'margin-left' => '2em',
+				)
+			);
+			$store->add_rule( '.wp-site-blocks > .aligncenter' )->add_declarations(
+				array(
+					'justify-content' => 'center',
+					'margin-left'     => 'auto',
+					'margin-right'    => 'auto',
+				)
+			);
 
 			$has_block_gap_support = _wp_array_get( $this->theme_json, array( 'settings', 'spacing', 'blockGap' ) ) !== null;
 			if ( $has_block_gap_support ) {
-				$block_rules .= '.wp-site-blocks > * { margin-block-start: 0; margin-block-end: 0; }';
-				$block_rules .= ".wp-site-blocks > * + * { margin-block-start: $block_gap_value; }";
+				$store->add_rule( '.wp-site-blocks > *' )->add_declarations(
+					array(
+						'margin-block-start' => '0',
+						'margin-block-end'   => '0',
+					)
+				);
+				$store->add_rule( '.wp-site-blocks > * + *' )->add_declarations( array( 'margin-block-start' => $block_gap_value ) );
 				// For backwards compatibility, ensure the legacy block gap CSS variable is still available.
-				$block_rules .= "$selector { --wp--style--block-gap: $block_gap_value; }";
+				$store->add_rule( $selector )->add_declarations( array( '--wp--style--block-gap' => $block_gap_value ) );
 			}
-			$block_rules .= $this->get_layout_styles( $block_metadata );
+			$store->add_store( $this->get_layout_styles_store( $block_metadata ) );
 		}
 
-		return $block_rules;
+		return $store;
+	}
+
+	/**
+	 * Gets the CSS rules for a particular block from theme.json.
+	 *
+	 * @param array $block_metadata Metadata about the block to get styles for.
+	 *
+	 * @return string Styles for the block.
+	 */
+	public function get_styles_for_block( $block_metadata ) {
+		return ( new WP_Style_Engine_Processor_Gutenberg( $this->get_block_styles_store( $block_metadata ) ) )->get_css();
+	}
+
+	/**
+	 * Returns a WP_Style_Engine_CSS_Rules_Store_Gutenberg object for the given nodes.
+	 *
+	 * @param array $style_nodes Nodes with styles.
+	 *
+	 * @return WP_Style_Engine_CSS_Rules_Store_Gutenberg
+	 */
+	protected function get_block_classes_store( $style_nodes ) {
+		$store = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_store( 'global-styles/block-classes' );
+		foreach ( $style_nodes as $metadata ) {
+			if ( null === $metadata['selector'] ) {
+				continue;
+			}
+			$store->add_store( $this->get_block_styles_store( $metadata ) );
+		}
+
+		return $store;
 	}
 
 	/**
@@ -812,16 +1003,7 @@ function( $pseudo_selector ) use ( $selector ) {
 	 * @return string The new stylesheet.
 	 */
 	protected function get_block_classes( $style_nodes ) {
-		$block_rules = '';
-
-		foreach ( $style_nodes as $metadata ) {
-			if ( null === $metadata['selector'] ) {
-				continue;
-			}
-			$block_rules .= static::get_styles_for_block( $metadata );
-		}
-
-		return $block_rules;
+		return ( new WP_Style_Engine_Processor_Gutenberg( $this->get_block_classes_store( $style_nodes ) ) )->get_css();
 	}
 
 	/**
@@ -1241,25 +1423,27 @@ public function set_spacing_sizes() {
 	}
 
 	/**
-	 * Get the CSS layout rules for a particular block from theme.json layout definitions.
+	 * Returns a WP_Style_Engine_CSS_Rules_Store_Gutenberg object for the given block metadata.
+	 *
+	 * @since 6.1.0
 	 *
 	 * @param array $block_metadata Metadata about the block to get styles for.
 	 *
-	 * @return string Layout styles for the block.
+	 * @return WP_Style_Engine_CSS_Rules_Store_Gutenberg
 	 */
-	protected function get_layout_styles( $block_metadata ) {
-		$block_rules = '';
-		$block_type  = null;
+	protected function get_layout_styles_store( $block_metadata ) {
+		$store      = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_store( 'global-styles/layout' );
+		$block_type = null;
 
 		// Skip outputting layout styles if explicitly disabled.
 		if ( current_theme_supports( 'disable-layout-styles' ) ) {
-			return $block_rules;
+			return $store;
 		}
 
 		if ( isset( $block_metadata['name'] ) ) {
 			$block_type = WP_Block_Type_Registry::get_instance()->get_registered( $block_metadata['name'] );
 			if ( ! block_has_support( $block_type, array( '__experimentalLayout' ), false ) ) {
-				return $block_rules;
+				return $store;
 			}
 		}
 
@@ -1321,10 +1505,7 @@ protected function get_layout_styles( $block_metadata ) {
 								foreach ( $spacing_rule['rules'] as $css_property => $css_value ) {
 									$current_css_value = is_string( $css_value ) ? $css_value : $block_gap_value;
 									if ( static::is_safe_css_declaration( $css_property, $current_css_value ) ) {
-										$declarations[] = array(
-											'name'  => $css_property,
-											'value' => $current_css_value,
-										);
+										$declarations[ $css_property ] = $current_css_value;
 									}
 								}
 
@@ -1346,7 +1527,7 @@ protected function get_layout_styles( $block_metadata ) {
 										$spacing_rule['selector']
 									);
 								}
-								$block_rules .= static::to_ruleset( $layout_selector, $declarations );
+								$store->add_rule( $layout_selector )->add_declarations( $declarations );
 							}
 						}
 					}
@@ -1378,15 +1559,7 @@ protected function get_layout_styles( $block_metadata ) {
 							$selector,
 							$class_name
 						);
-						$block_rules    .= static::to_ruleset(
-							$layout_selector,
-							array(
-								array(
-									'name'  => 'display',
-									'value' => $layout_definition['displayMode'],
-								),
-							)
-						);
+						$store->add_rule( $layout_selector )->add_declarations( array( 'display' => $layout_definition['displayMode'] ) );
 					}
 
 					foreach ( $base_style_rules as $base_style_rule ) {
@@ -1399,10 +1572,7 @@ protected function get_layout_styles( $block_metadata ) {
 						) {
 							foreach ( $base_style_rule['rules'] as $css_property => $css_value ) {
 								if ( static::is_safe_css_declaration( $css_property, $css_value ) ) {
-									$declarations[] = array(
-										'name'  => $css_property,
-										'value' => $css_value,
-									);
+									$declarations[ $css_property ] = $css_value;
 								}
 							}
 
@@ -1412,12 +1582,87 @@ protected function get_layout_styles( $block_metadata ) {
 								$class_name,
 								$base_style_rule['selector']
 							);
-							$block_rules    .= static::to_ruleset( $layout_selector, $declarations );
+							$store->add_rule( $layout_selector )->add_declarations( $declarations );
 						}
 					}
 				}
 			}
 		}
-		return $block_rules;
+		return $store;
+	}
+
+	/**
+	 * Get the CSS layout rules for a particular block from theme.json layout definitions.
+	 *
+	 * @param array $block_metadata Metadata about the block to get styles for.
+	 *
+	 * @return string Layout styles for the block.
+	 */
+	protected function get_layout_styles( $block_metadata ) {
+		return ( new WP_Style_Engine_Processor_Gutenberg( $this->get_layout_styles_store( $block_metadata ) ) )->get_css();
+	}
+
+	/**
+	 * Converts a declarations array with name/value keys to a plain array with property => value pairs.
+	 *
+	 * @param array $declarations Declarations array.
+	 *
+	 * @return array
+	 */
+	protected function get_plain_declarations_from_pairs( $declarations ) {
+		$plain_declarations = array();
+		foreach ( $declarations as $declaration ) {
+			$plain_declarations[ $declaration['name'] ] = $declaration['value'];
+		}
+		return $plain_declarations;
+	}
+
+	/**
+	 * Given a settings array, it returns the generated rulesets
+	 * for the preset classes.
+	 *
+	 * @since 5.8.0
+	 * @since 5.9.0 Added the `$origins` parameter.
+	 *
+	 * @param array  $settings Settings to process.
+	 * @param string $selector Selector wrapping the classes.
+	 * @param array  $origins  List of origins to process.
+	 * @return string The result of processing the presets.
+	 */
+	protected static function compute_preset_classes_store( $settings, $selector, $origins ) {
+		$store = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_store( md5( json_encode( array( $settings, $selector, $origins ) ) ) );
+		if ( static::ROOT_BLOCK_SELECTOR === $selector ) {
+			// Classes at the global level do not need any CSS prefixed,
+			// and we don't want to increase its specificity.
+			$selector = '';
+		}
+
+		foreach ( static::PRESETS_METADATA as $preset_metadata ) {
+			$slugs = static::get_settings_slugs( $settings, $preset_metadata, $origins );
+			foreach ( $preset_metadata['classes'] as $class => $property ) {
+				foreach ( $slugs as $slug ) {
+					$css_var    = static::replace_slug_in_string( $preset_metadata['css_vars'], $slug );
+					$class_name = static::replace_slug_in_string( $class, $slug );
+					$store->add_rule( static::append_to_selector( $selector, $class_name ) )->add_declarations( array( $property => 'var(' . $css_var . ') !important' ) );
+				}
+			}
+		}
+		return $store;
+	}
+
+	/**
+	 * Given a settings array, it returns the generated rulesets
+	 * for the preset classes.
+	 *
+	 * @since 5.8.0
+	 * @since 5.9.0 Added the `$origins` parameter.
+	 *
+	 * @param array  $settings Settings to process.
+	 * @param string $selector Selector wrapping the classes.
+	 * @param array  $origins  List of origins to process.
+	 * @return string The result of processing the presets.
+	 */
+	protected static function compute_preset_classes( $settings, $selector, $origins ) {
+		return ( new WP_Style_Engine_Processor_Gutenberg( static::compute_preset_classes_store( $settings, $selector, $origins ) ) )->get_css();
 	}
 }
diff --git a/packages/style-engine/class-wp-style-engine-css-declarations.php b/packages/style-engine/class-wp-style-engine-css-declarations.php
index fe686edddaac0..2f90570f2140b 100644
--- a/packages/style-engine/class-wp-style-engine-css-declarations.php
+++ b/packages/style-engine/class-wp-style-engine-css-declarations.php
@@ -58,7 +58,7 @@ public function add_declaration( $property, $value ) {
 		}
 
 		// Trim the value. If empty, bail early.
-		$value = trim( $value );
+		$value = $this->sanitize_value( $value );
 		if ( '' === $value ) {
 			return;
 		}
@@ -121,13 +121,19 @@ public function get_declarations() {
 	public function get_declarations_string() {
 		$declarations_array  = $this->get_declarations();
 		$declarations_output = '';
+
 		foreach ( $declarations_array as $property => $value ) {
-			$filtered_declaration = esc_html( safecss_filter_attr( "{$property}: {$value}" ) );
+			// Account for CSS variables.
+			if ( 0 === strpos( $property, '--' ) || ( 'display' === $property && 'none' !== $value ) ) {
+				$declarations_output .= "{$property}:{$value};";
+				continue;
+			}
+			$filtered_declaration = safecss_filter_attr( "{$property}:{$value}" );
 			if ( $filtered_declaration ) {
-				$declarations_output .= $filtered_declaration . '; ';
+				$declarations_output .= $filtered_declaration . ';';
 			}
 		}
-		return rtrim( $declarations_output );
+		return $declarations_output;
 	}
 
 	/**
@@ -140,4 +146,19 @@ public function get_declarations_string() {
 	protected function sanitize_property( $property ) {
 		return sanitize_key( $property );
 	}
+
+	/**
+	 * Sanitize values.
+	 *
+	 * @param string $value The CSS value.
+	 *
+	 * @return string The sanitized value.
+	 */
+	protected function sanitize_value( $value ) {
+		// Escape HTML.
+		$value = esc_html( $value );
+		// Fix quotes to account for URLs.
+		$value = str_replace( array( ''', ''', '"', '"', '"', ''' ), array( "'", "'", '"', '"', '"', "'" ), $value );
+		return trim( $value );
+	}
 }
diff --git a/packages/style-engine/class-wp-style-engine-css-rule.php b/packages/style-engine/class-wp-style-engine-css-rule.php
index 5429b282f328d..b21cef2d65bf0 100644
--- a/packages/style-engine/class-wp-style-engine-css-rule.php
+++ b/packages/style-engine/class-wp-style-engine-css-rule.php
@@ -110,6 +110,11 @@ public function get_selector() {
 	 * @return string
 	 */
 	public function get_css() {
-		return $this->get_selector() . ' {' . $this->declarations->get_declarations_string() . '}';
+		$styles = $this->declarations->get_declarations_string();
+		if ( empty( $styles ) ) {
+			return '';
+		}
+
+		return $this->get_selector() . '{' . $styles . '}';
 	}
 }
diff --git a/packages/style-engine/class-wp-style-engine-css-rules-store.php b/packages/style-engine/class-wp-style-engine-css-rules-store.php
index d3cc079afe6e9..7298e45f8c0ab 100644
--- a/packages/style-engine/class-wp-style-engine-css-rules-store.php
+++ b/packages/style-engine/class-wp-style-engine-css-rules-store.php
@@ -140,4 +140,21 @@ public function add_rule( $selector ) {
 	public function remove_rule( $selector ) {
 		unset( $this->rules[ $selector ] );
 	}
+
+	/**
+	 * Add a store. This method effectively merges the rules of the defined store into the current store,
+	 * and removes them from the original store to avoid duplication.
+	 *
+	 * @param WP_Style_Engine_CSS_Rules_Store $store The store to merge.
+	 *
+	 * @return WP_Style_Engine_CSS_Rules_Store Returns the merged store.
+	 */
+	public function add_store( WP_Style_Engine_CSS_Rules_Store $store ) {
+		$incoming_rules = $store->get_all_rules();
+		foreach ( $incoming_rules as $rule ) {
+			$this->add_rule( $rule->get_selector() )->add_declarations( $rule->get_declarations() );
+			$store->remove_rule( $rule->get_selector() );
+		}
+		return $this;
+	}
 }
diff --git a/packages/style-engine/phpunit/class-wp-style-engine-css-declarations-test.php b/packages/style-engine/phpunit/class-wp-style-engine-css-declarations-test.php
index f093a496d538a..54bacf795d7f4 100644
--- a/packages/style-engine/phpunit/class-wp-style-engine-css-declarations-test.php
+++ b/packages/style-engine/phpunit/class-wp-style-engine-css-declarations-test.php
@@ -84,7 +84,7 @@ public function test_generate_css_declarations_string() {
 		$css_declarations   = new WP_Style_Engine_CSS_Declarations( $input_declarations );
 
 		$this->assertSame(
-			'color: red; border-top-left-radius: 99px; text-decoration: underline;',
+			'color:red;border-top-left-radius:99px;text-decoration:underline;',
 			$css_declarations->get_declarations_string()
 		);
 	}
@@ -101,7 +101,7 @@ public function test_remove_unsafe_properties_and_values() {
 		$css_declarations   = new WP_Style_Engine_CSS_Declarations( $input_declarations );
 
 		$this->assertSame(
-			'color: <red/>; margin-right: 10em;',
+			'margin-right:10em;',
 			$css_declarations->get_declarations_string()
 		);
 	}
@@ -118,13 +118,13 @@ public function test_remove_declaration() {
 		$css_declarations   = new WP_Style_Engine_CSS_Declarations( $input_declarations );
 
 		$this->assertSame(
-			'color: tomato; margin: 10em 10em 20em 1px; font-family: Happy Font serif;',
+			'color:tomato;margin:10em 10em 20em 1px;font-family:Happy Font serif;',
 			$css_declarations->get_declarations_string()
 		);
 
 		$css_declarations->remove_declaration( 'color' );
 		$this->assertSame(
-			'margin: 10em 10em 20em 1px; font-family: Happy Font serif;',
+			'margin:10em 10em 20em 1px;font-family:Happy Font serif;',
 			$css_declarations->get_declarations_string()
 		);
 	}
@@ -141,13 +141,13 @@ public function test_remove_declarations() {
 		$css_declarations   = new WP_Style_Engine_CSS_Declarations( $input_declarations );
 
 		$this->assertSame(
-			'color: cucumber; margin: 10em 10em 20em 1px; font-family: Happy Font serif;',
+			'color:cucumber;margin:10em 10em 20em 1px;font-family:Happy Font serif;',
 			$css_declarations->get_declarations_string()
 		);
 
 		$css_declarations->remove_declarations( array( 'color', 'margin' ) );
 		$this->assertSame(
-			'font-family: Happy Font serif;',
+			'font-family:Happy Font serif;',
 			$css_declarations->get_declarations_string()
 		);
 	}
diff --git a/packages/style-engine/phpunit/class-wp-style-engine-css-rule-test.php b/packages/style-engine/phpunit/class-wp-style-engine-css-rule-test.php
index 80547d998fb87..7d865e7ee6ab2 100644
--- a/packages/style-engine/phpunit/class-wp-style-engine-css-rule-test.php
+++ b/packages/style-engine/phpunit/class-wp-style-engine-css-rule-test.php
@@ -27,7 +27,7 @@ public function test_instantiate_with_selector_and_rules() {
 
 		$this->assertSame( $selector, $css_rule->get_selector() );
 
-		$expected = "$selector {{$css_declarations->get_declarations_string()}}";
+		$expected = "$selector{{$css_declarations->get_declarations_string()}}";
 		$this->assertSame( $expected, $css_rule->get_css() );
 	}
 
@@ -45,7 +45,7 @@ public function test_dedupe_properties_in_rules() {
 		$css_rule                    = new WP_Style_Engine_CSS_Rule( $selector, $first_declaration );
 		$css_rule->add_declarations( new WP_Style_Engine_CSS_Declarations( $overwrite_first_declaration ) );
 
-		$expected = '.taggart {font-size: 4px;}';
+		$expected = '.taggart{font-size:4px;}';
 		$this->assertSame( $expected, $css_rule->get_css() );
 	}
 
@@ -60,7 +60,7 @@ public function test_add_declarations() {
 		$css_rule                   = new WP_Style_Engine_CSS_Rule( '.hill-street-blues', $some_css_declarations );
 		$css_rule->add_declarations( $some_more_css_declarations );
 
-		$expected = '.hill-street-blues {margin-top: 10px; font-size: 1rem;}';
+		$expected = '.hill-street-blues{margin-top:10px;font-size:1rem;}';
 		$this->assertSame( $expected, $css_rule->get_css() );
 	}
 
@@ -89,7 +89,7 @@ public function test_get_css() {
 		);
 		$css_declarations   = new WP_Style_Engine_CSS_Declarations( $input_declarations );
 		$css_rule           = new WP_Style_Engine_CSS_Rule( $selector, $css_declarations );
-		$expected           = "$selector {{$css_declarations->get_declarations_string()}}";
+		$expected           = "$selector{{$css_declarations->get_declarations_string()}}";
 
 		$this->assertSame( $expected, $css_rule->get_css() );
 	}
diff --git a/packages/style-engine/phpunit/class-wp-style-engine-css-rules-store-test.php b/packages/style-engine/phpunit/class-wp-style-engine-css-rules-store-test.php
index 9fe664752e4bf..5336c4cd92263 100644
--- a/packages/style-engine/phpunit/class-wp-style-engine-css-rules-store-test.php
+++ b/packages/style-engine/phpunit/class-wp-style-engine-css-rules-store-test.php
@@ -85,19 +85,19 @@ public function test_add_rule() {
 		$new_pie_store = WP_Style_Engine_CSS_Rules_Store::get_store( 'meat-pie' );
 		$selector      = '.wp-block-sauce a:hover';
 		$store_rule    = $new_pie_store->add_rule( $selector );
-		$expected      = "$selector {}";
-		$this->assertEquals( $expected, $store_rule->get_css() );
+		$this->assertEquals( '', $store_rule->get_css() );
 
-		$pie_declarations = array(
-			'color'         => 'brown',
-			'border-color'  => 'yellow',
-			'border-radius' => '10rem',
+		$css_declarations = new WP_Style_Engine_CSS_Declarations(
+			array(
+				'color'         => 'brown',
+				'border-color'  => 'yellow',
+				'border-radius' => '10rem',
+			)
 		);
-		$css_declarations = new WP_Style_Engine_CSS_Declarations( $pie_declarations );
-		$store_rule->add_declarations( $css_declarations );
 
-		$store_rule = $new_pie_store->add_rule( $selector );
-		$expected   = "$selector {{$css_declarations->get_declarations_string()}}";
+		$new_pie_store->add_rule( $selector )->add_declarations( $css_declarations );
+		$styles   = $css_declarations->get_declarations_string();
+		$expected = $selector . '{' . $styles . '}';
 		$this->assertEquals( $expected, $store_rule->get_css() );
 	}
 
diff --git a/packages/style-engine/phpunit/class-wp-style-engine-processor-test.php b/packages/style-engine/phpunit/class-wp-style-engine-processor-test.php
index ebee00f05ce16..8eb5cb1f9849f 100644
--- a/packages/style-engine/phpunit/class-wp-style-engine-processor-test.php
+++ b/packages/style-engine/phpunit/class-wp-style-engine-processor-test.php
@@ -58,7 +58,7 @@ public function test_return_store_rules_as_css() {
 		);
 		$a_nice_renderer = new WP_Style_Engine_Processor_Gutenberg();
 		$a_nice_renderer->add_store( $a_nice_store );
-		$this->assertEquals( '.a-nice-rule {color: var(--nice-color); background-color: purple;}.a-nicer-rule {font-family: Nice sans; font-size: 1em; background-color: purple;}', $a_nice_renderer->get_css() );
+		$this->assertEquals( '.a-nice-rule{color:var(--nice-color);background-color:purple;}.a-nicer-rule{font-family:Nice sans;font-size:1em;background-color:purple;}', $a_nice_renderer->get_css() );
 	}
 
 	/**
@@ -95,7 +95,7 @@ public function test_dedupe_and_merge_css_declarations() {
 			)
 		);
 		$an_excellent_processor->add_rules( $yet_another_excellent_rule );
-		$this->assertEquals( '.an-excellent-rule {color: var(--excellent-color); border-style: dashed; border-color: brown; border-width: 2px;}', $an_excellent_processor->get_css() );
+		$this->assertEquals( '.an-excellent-rule{color:var(--excellent-color);border-style:dashed;border-color:brown;border-width:2px;}', $an_excellent_processor->get_css() );
 	}
 
 	/**
@@ -121,7 +121,7 @@ public function test_combine_css_rules() {
 		$a_sweet_processor = new WP_Style_Engine_Processor();
 		$a_sweet_processor->add_rules( array( $a_sweet_rule, $a_sweeter_rule ) );
 
-		$this->assertEquals( '.a-sweet-rule,#an-even-sweeter-rule > marquee {color: var(--sweet-color); background-color: purple;}', $a_sweet_processor->get_css() );
+		$this->assertEquals( '.a-sweet-rule,#an-even-sweeter-rule > marquee{color:var(--sweet-color);background-color:purple;}', $a_sweet_processor->get_css() );
 	}
 		/**
 		 * Should combine and store CSS rules.
@@ -160,6 +160,6 @@ public function test_combine_previously_added_css_rules() {
 		);
 		$a_lovely_processor->add_rules( $a_perfectly_lovely_rule );
 
-		$this->assertEquals( '.a-lovely-rule,.a-lovelier-rule,.a-most-lovely-rule,.a-perfectly-lovely-rule {border-color: purple;}', $a_lovely_processor->get_css() );
+		$this->assertEquals( '.a-lovely-rule,.a-lovelier-rule,.a-most-lovely-rule,.a-perfectly-lovely-rule{border-color:purple;}', $a_lovely_processor->get_css() );
 	}
 }
diff --git a/packages/style-engine/phpunit/class-wp-style-engine-test.php b/packages/style-engine/phpunit/class-wp-style-engine-test.php
index 14938e075fa26..d3893e092b79c 100644
--- a/packages/style-engine/phpunit/class-wp-style-engine-test.php
+++ b/packages/style-engine/phpunit/class-wp-style-engine-test.php
@@ -100,7 +100,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array( 'convert_vars_to_classnames' => true ),
 				'expected_output' => array(
-					'css'          => 'border-style: dotted; border-width: 2rem; padding: 0; margin: 111px;',
+					'css'          => 'border-style:dotted;border-width:2rem;padding:0;margin:111px;',
 					'declarations' => array(
 						'border-style' => 'dotted',
 						'border-width' => '2rem',
@@ -176,7 +176,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => null,
 				'expected_output' => array(
-					'css'          => 'border-top-left-radius: 99px; border-top-right-radius: 98px; border-bottom-left-radius: 97px; border-bottom-right-radius: 96px; padding-top: 42px; padding-left: 2%; padding-bottom: 44px; padding-right: 5rem; margin-top: 12rem; margin-left: 2vh; margin-bottom: 2px; margin-right: 10em;',
+					'css'          => 'border-top-left-radius:99px;border-top-right-radius:98px;border-bottom-left-radius:97px;border-bottom-right-radius:96px;padding-top:42px;padding-left:2%;padding-bottom:44px;padding-right:5rem;margin-top:12rem;margin-left:2vh;margin-bottom:2px;margin-right:10em;',
 					'declarations' => array(
 						'border-top-left-radius'     => '99px',
 						'border-top-right-radius'    => '98px',
@@ -209,7 +209,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => null,
 				'expected_output' => array(
-					'css'          => 'font-family: Roboto,Oxygen-Sans,Ubuntu,sans-serif; font-style: italic; font-weight: 800; line-height: 1.3; text-decoration: underline; text-transform: uppercase; letter-spacing: 2;',
+					'css'          => 'font-family:Roboto,Oxygen-Sans,Ubuntu,sans-serif;font-style:italic;font-weight:800;line-height:1.3;text-decoration:underline;text-transform:uppercase;letter-spacing:2;',
 					'declarations' => array(
 						'font-size'       => 'clamp(2em, 2vw, 4em)',
 						'font-family'     => 'Roboto,Oxygen-Sans,Ubuntu,sans-serif',
@@ -302,7 +302,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array(),
 				'expected_output' => array(
-					'css'          => 'color: var(--wp--preset--color--teal-independents);',
+					'css'          => 'color:var(--wp--preset--color--teal-independents);',
 					'declarations' => array(
 						'color' => 'var(--wp--preset--color--teal-independents)',
 					),
@@ -319,7 +319,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array(),
 				'expected_output' => array(
-					'css'          => 'color: #fff;',
+					'css'          => 'color:#fff;',
 					'declarations' => array(
 						'color' => '#fff',
 					),
@@ -353,7 +353,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array(),
 				'expected_output' => array(
-					'css'          => 'padding: var(--wp--preset--spacing--20); margin: var(--wp--preset--spacing--10);',
+					'css'          => 'padding:var(--wp--preset--spacing--20);margin:var(--wp--preset--spacing--10);',
 					'declarations' => array(
 						'padding' => 'var(--wp--preset--spacing--20)',
 						'margin'  => 'var(--wp--preset--spacing--10)',
@@ -380,7 +380,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array(),
 				'expected_output' => array(
-					'css'          => 'padding-left: var(--wp--preset--spacing--30); padding-right: var(--wp--preset--spacing--40); padding-top: 14px; padding-bottom: 14px; margin-left: var(--wp--preset--spacing--10); margin-right: var(--wp--preset--spacing--20); margin-top: 1rem; margin-bottom: 1rem;',
+					'css'          => 'padding-left:var(--wp--preset--spacing--30);padding-right:var(--wp--preset--spacing--40);padding-top:14px;padding-bottom:14px;margin-left:var(--wp--preset--spacing--10);margin-right:var(--wp--preset--spacing--20);margin-top:1rem;margin-bottom:1rem;',
 					'declarations' => array(
 						'padding-left'   => 'var(--wp--preset--spacing--30)',
 						'padding-right'  => 'var(--wp--preset--spacing--40)',
@@ -407,7 +407,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array(),
 				'expected_output' => array(
-					'css'          => 'margin-top: 1rem; margin-bottom: 0;',
+					'css'          => 'margin-top:1rem;margin-bottom:0;',
 					'declarations' => array(
 						'margin-top'    => '1rem',
 						'margin-bottom' => '0',
@@ -456,7 +456,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array(),
 				'expected_output' => array(
-					'css'          => 'border-top-color: #fe1; border-top-width: 1.5rem; border-top-style: dashed; border-right-color: #fe2; border-right-width: 1.4rem; border-right-style: solid; border-bottom-color: #fe3; border-bottom-width: 1.3rem; border-left-color: var(--wp--preset--color--swampy-yellow); border-left-width: 0.5rem; border-left-style: dotted;',
+					'css'          => 'border-top-color:#fe1;border-top-width:1.5rem;border-top-style:dashed;border-right-color:#fe2;border-right-width:1.4rem;border-right-style:solid;border-bottom-color:#fe3;border-bottom-width:1.3rem;border-left-color:var(--wp--preset--color--swampy-yellow);border-left-width:0.5rem;border-left-style:dotted;',
 					'declarations' => array(
 						'border-top-color'    => '#fe1',
 						'border-top-width'    => '1.5rem',
@@ -499,7 +499,7 @@ public function data_get_styles_fixtures() {
 				),
 				'options'         => array(),
 				'expected_output' => array(
-					'css'          => 'border-bottom-color: var(--wp--preset--color--terrible-lizard);',
+					'css'          => 'border-bottom-color:var(--wp--preset--color--terrible-lizard);',
 					'declarations' => array(
 						'border-bottom-color' => 'var(--wp--preset--color--terrible-lizard)',
 					),
diff --git a/phpunit/block-supports/border-test.php b/phpunit/block-supports/border-test.php
index a199dd34ad833..dd2b279867aeb 100644
--- a/phpunit/block-supports/border-test.php
+++ b/phpunit/block-supports/border-test.php
@@ -117,7 +117,7 @@ function test_border_color_slug_with_numbers_is_kebab_cased_properly() {
 		$actual   = gutenberg_apply_border_support( $block_type, $block_atts );
 		$expected = array(
 			'class' => 'has-border-color has-red-border-color',
-			'style' => 'border-radius: 10px; border-style: dashed; border-width: 1px;',
+			'style' => 'border-radius:10px;border-style:dashed;border-width:1px;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -179,7 +179,7 @@ function test_flat_border_with_individual_skipped_serialization() {
 
 		$actual   = gutenberg_apply_border_support( $block_type, $block_atts );
 		$expected = array(
-			'style' => 'border-style: dotted; border-width: 1px;',
+			'style' => 'border-style:dotted;border-width:1px;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -208,7 +208,7 @@ function test_split_border_radius() {
 		);
 		$actual      = gutenberg_apply_border_support( $block_type, $block_attrs );
 		$expected    = array(
-			'style' => 'border-top-left-radius: 1em; border-top-right-radius: 2rem; border-bottom-left-radius: 30px; border-bottom-right-radius: 4vh;',
+			'style' => 'border-top-left-radius:1em;border-top-right-radius:2rem;border-bottom-left-radius:30px;border-bottom-right-radius:4vh;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -237,7 +237,7 @@ function test_flat_border_with_custom_color() {
 		$actual      = gutenberg_apply_border_support( $block_type, $block_attrs );
 		$expected    = array(
 			'class' => 'has-border-color',
-			'style' => 'border-color: #72aee6; border-style: dashed; border-width: 2px;',
+			'style' => 'border-color:#72aee6;border-style:dashed;border-width:2px;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -282,7 +282,7 @@ function test_split_borders_with_custom_colors() {
 		);
 		$actual      = gutenberg_apply_border_support( $block_type, $block_attrs );
 		$expected    = array(
-			'style' => 'border-top-width: 2px; border-top-color: #72aee6; border-top-style: dashed; border-right-width: 0.25rem; border-right-color: #e65054; border-right-style: dotted; border-bottom-width: 0.5em; border-bottom-color: #007017; border-bottom-style: solid; border-left-width: 1px; border-left-color: #f6f7f7; border-left-style: solid;',
+			'style' => 'border-top-width:2px;border-top-color:#72aee6;border-top-style:dashed;border-right-width:0.25rem;border-right-color:#e65054;border-right-style:dotted;border-bottom-width:0.5em;border-bottom-color:#007017;border-bottom-style:solid;border-left-width:1px;border-left-color:#f6f7f7;border-left-style:solid;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -372,7 +372,7 @@ function test_split_borders_with_skipped_individual_feature_serialization() {
 		);
 		$actual      = gutenberg_apply_border_support( $block_type, $block_attrs );
 		$expected    = array(
-			'style' => 'border-top-color: #72aee6; border-right-color: #e65054; border-bottom-color: #007017; border-left-color: #f6f7f7;',
+			'style' => 'border-top-color:#72aee6;border-right-color:#e65054;border-bottom-color:#007017;border-left-color:#f6f7f7;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -409,7 +409,7 @@ function test_partial_split_borders() {
 		);
 		$actual      = gutenberg_apply_border_support( $block_type, $block_attrs );
 		$expected    = array(
-			'style' => 'border-top-width: 2px; border-top-color: #72aee6; border-top-style: dashed; border-right-width: 0.25rem; border-right-color: #e65054; border-left-style: solid;',
+			'style' => 'border-top-width:2px;border-top-color:#72aee6;border-top-style:dashed;border-right-width:0.25rem;border-right-color:#e65054;border-left-style:solid;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -454,7 +454,7 @@ function test_split_borders_with_named_colors() {
 		);
 		$actual      = gutenberg_apply_border_support( $block_type, $block_attrs );
 		$expected    = array(
-			'style' => 'border-top-width: 2px; border-top-color: var(--wp--preset--color--red); border-top-style: dashed; border-right-width: 0.25rem; border-right-color: var(--wp--preset--color--green); border-right-style: dotted; border-bottom-width: 0.5em; border-bottom-color: var(--wp--preset--color--blue); border-bottom-style: solid; border-left-width: 1px; border-left-color: var(--wp--preset--color--yellow); border-left-style: solid;',
+			'style' => 'border-top-width:2px;border-top-color:var(--wp--preset--color--red);border-top-style:dashed;border-right-width:0.25rem;border-right-color:var(--wp--preset--color--green);border-right-style:dotted;border-bottom-width:0.5em;border-bottom-color:var(--wp--preset--color--blue);border-bottom-style:solid;border-left-width:1px;border-left-color:var(--wp--preset--color--yellow);border-left-style:solid;',
 		);
 
 		$this->assertSame( $expected, $actual );
diff --git a/phpunit/block-supports/colors-test.php b/phpunit/block-supports/colors-test.php
index fba82fafb4bec..89b3a9192270e 100644
--- a/phpunit/block-supports/colors-test.php
+++ b/phpunit/block-supports/colors-test.php
@@ -136,7 +136,7 @@ function test_gradient_with_individual_skipped_serialization_block_supports() {
 		$actual   = gutenberg_apply_colors_support( $block_type, $block_atts );
 		$expected = array(
 			'class' => 'has-text-color',
-			'style' => 'color: #d92828;',
+			'style' => 'color:#d92828;',
 		);
 
 		$this->assertSame( $expected, $actual );
diff --git a/phpunit/block-supports/spacing-test.php b/phpunit/block-supports/spacing-test.php
index 51b537bff4d14..4caaf12911f9a 100644
--- a/phpunit/block-supports/spacing-test.php
+++ b/phpunit/block-supports/spacing-test.php
@@ -62,7 +62,7 @@ function test_spacing_style_is_applied() {
 
 		$actual   = gutenberg_apply_spacing_support( $block_type, $block_atts );
 		$expected = array(
-			'style' => 'padding: 111px; margin-top: 1px; margin-right: 2px; margin-bottom: 3px; margin-left: 4px;',
+			'style' => 'padding:111px;margin-top:1px;margin-right:2px;margin-bottom:3px;margin-left:4px;',
 		);
 
 		$this->assertSame( $expected, $actual );
@@ -152,7 +152,7 @@ function test_margin_with_individual_skipped_serialization_block_supports() {
 
 		$actual   = gutenberg_apply_spacing_support( $block_type, $block_atts );
 		$expected = array(
-			'style' => 'padding-top: 1px; padding-right: 2px; padding-bottom: 3px; padding-left: 4px;',
+			'style' => 'padding-top:1px;padding-right:2px;padding-bottom:3px;padding-left:4px;',
 		);
 
 		$this->assertSame( $expected, $actual );
diff --git a/phpunit/block-supports/typography-test.php b/phpunit/block-supports/typography-test.php
index f5b5ac954f9e2..297c90a1bc8a9 100644
--- a/phpunit/block-supports/typography-test.php
+++ b/phpunit/block-supports/typography-test.php
@@ -75,7 +75,7 @@ function test_font_family_with_legacy_inline_styles_using_a_value() {
 		$block_atts = array( 'style' => array( 'typography' => array( 'fontFamily' => 'serif' ) ) );
 
 		$actual   = gutenberg_apply_typography_support( $block_type, $block_atts );
-		$expected = array( 'style' => 'font-family: serif;' );
+		$expected = array( 'style' => 'font-family:serif;' );
 
 		$this->assertSame( $expected, $actual );
 	}
@@ -175,7 +175,7 @@ function test_font_family_with_legacy_inline_styles_using_a_css_var() {
 		$block_atts = array( 'style' => array( 'typography' => array( 'fontFamily' => 'var:preset|font-family|h1' ) ) );
 
 		$actual   = gutenberg_apply_typography_support( $block_type, $block_atts );
-		$expected = array( 'style' => 'font-family: var(--wp--preset--font-family--h-1);' );
+		$expected = array( 'style' => 'font-family:var(--wp--preset--font-family--h-1);' );
 
 		$this->assertSame( $expected, $actual );
 	}
diff --git a/phpunit/class-wp-theme-json-test.php b/phpunit/class-wp-theme-json-test.php
index 34d9905743c61..103a6ac211ef8 100644
--- a/phpunit/class-wp-theme-json-test.php
+++ b/phpunit/class-wp-theme-json-test.php
@@ -7,12 +7,27 @@
  */
 
 class WP_Theme_JSON_Gutenberg_Test extends WP_UnitTestCase {
+	/**
+	 * Reset the Style-Engine stores for global-styles.
+	 */
+	public function reset_style_engine_stores() {
+		$stores = WP_Style_Engine_CSS_Rules_Store_Gutenberg::get_stores();
+		foreach ( $stores as $store ) {
+			$rules = $store->get_all_rules();
+			foreach ( array_keys( $rules ) as $selector ) {
+				$store->remove_rule( $selector );
+			}
+		}
+	}
 	/**
 	 * @dataProvider data_get_layout_definitions
 	 *
 	 * @param array $layout_definitions Layout definitions as stored in core theme.json.
 	 */
 	public function test_get_stylesheet_generates_layout_styles( $layout_definitions ) {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version'  => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -35,7 +50,7 @@ public function test_get_stylesheet_generates_layout_styles( $layout_definitions
 
 		// Results also include root site blocks styles.
 		$this->assertEquals(
-			'body { margin: 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; }.wp-site-blocks > * { margin-block-start: 0; margin-block-end: 0; }.wp-site-blocks > * + * { margin-block-start: 1em; }body { --wp--style--block-gap: 1em; }body .is-layout-flow > *{margin-block-start: 0;margin-block-end: 0;}body .is-layout-flow > * + *{margin-block-start: 1em;margin-block-end: 0;}body .is-layout-flex{gap: 1em;}body .is-layout-flow > .alignleft{float: left;margin-inline-start: 0;margin-inline-end: 2em;}body .is-layout-flow > .alignright{float: right;margin-inline-start: 2em;margin-inline-end: 0;}body .is-layout-flow > .aligncenter{margin-left: auto !important;margin-right: auto !important;}body .is-layout-flex{display: flex;}body .is-layout-flex{flex-wrap: wrap;align-items: center;}',
+			'body{margin:0;--wp--style--block-gap:1em;}.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;}.wp-site-blocks > * + *{margin-block-start:1em;}body .is-layout-flow > * + *{margin-block-start:1em;margin-block-end:0;}body .is-layout-flex{gap:1em;display:flex;flex-wrap:wrap;align-items:center;}body .is-layout-flow > .alignleft{float:left;margin-inline-start:0;margin-inline-end:2em;}body .is-layout-flow > .alignright{float:right;margin-inline-start:2em;margin-inline-end:0;}body .is-layout-flow > .aligncenter{margin-left:auto !important;margin-right:auto !important;}.wp-site-blocks > *,body .is-layout-flow > *{margin-block-start:0;margin-block-end:0;}',
 			$theme_json->get_stylesheet( array( 'styles' ) )
 		);
 	}
@@ -46,6 +61,9 @@ public function test_get_stylesheet_generates_layout_styles( $layout_definitions
 	 * @param array $layout_definitions Layout definitions as stored in core theme.json.
 	 */
 	public function test_get_stylesheet_generates_fallback_gap_layout_styles( $layout_definitions ) {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version'  => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -80,6 +98,9 @@ public function test_get_stylesheet_generates_fallback_gap_layout_styles( $layou
 	 * @param array $layout_definitions Layout definitions as stored in core theme.json.
 	 */
 	public function test_get_stylesheet_generates_base_fallback_gap_layout_styles( $layout_definitions ) {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version'  => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -217,6 +238,9 @@ public function data_get_layout_definitions() {
 		);
 	}
 	function test_get_stylesheet_handles_whitelisted_element_pseudo_selectors() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -249,7 +273,7 @@ function test_get_stylesheet_handles_whitelisted_element_pseudo_selectors() {
 			)
 		);
 
-		$base_styles = 'body { margin: 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; }';
+		$base_styles = 'body{margin: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;}';
 
 		$element_styles = 'a:where(:not(.wp-element-button)){background-color: red;color: green;}a:where(:not(.wp-element-button)):hover{background-color: green;color: red;font-size: 10em;text-transform: uppercase;}a:where(:not(.wp-element-button)):focus{background-color: black;color: yellow;}';
 
@@ -260,6 +284,9 @@ function test_get_stylesheet_handles_whitelisted_element_pseudo_selectors() {
 	}
 
 	function test_get_stylesheet_handles_only_pseudo_selector_rules_for_given_property() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -288,7 +315,7 @@ function test_get_stylesheet_handles_only_pseudo_selector_rules_for_given_proper
 			)
 		);
 
-		$base_styles = 'body { margin: 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; }';
+		$base_styles = 'body{margin: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;}';
 
 		$element_styles = 'a:where(:not(.wp-element-button)):hover{background-color: green;color: red;font-size: 10em;text-transform: uppercase;}a:where(:not(.wp-element-button)):focus{background-color: black;color: yellow;}';
 
@@ -299,6 +326,9 @@ function test_get_stylesheet_handles_only_pseudo_selector_rules_for_given_proper
 	}
 
 	function test_get_stylesheet_ignores_pseudo_selectors_on_non_whitelisted_elements() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -327,9 +357,9 @@ function test_get_stylesheet_ignores_pseudo_selectors_on_non_whitelisted_element
 			)
 		);
 
-		$base_styles = 'body { margin: 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; }';
+		$base_styles = 'body{margin: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;}';
 
-		$element_styles = 'h4{background-color: red;color: green;}';
+		$element_styles = 'h4{background-color:red;color:green;}';
 
 		$expected = $base_styles . $element_styles;
 
@@ -338,6 +368,9 @@ function test_get_stylesheet_ignores_pseudo_selectors_on_non_whitelisted_element
 	}
 
 	function test_get_stylesheet_ignores_non_whitelisted_pseudo_selectors() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -366,7 +399,7 @@ function test_get_stylesheet_ignores_non_whitelisted_pseudo_selectors() {
 			)
 		);
 
-		$base_styles = 'body { margin: 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; }';
+		$base_styles = 'body{margin: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;}';
 
 		$element_styles = 'a:where(:not(.wp-element-button)){background-color: red;color: green;}a:where(:not(.wp-element-button)):hover{background-color: green;color: red;}';
 
@@ -378,6 +411,9 @@ function test_get_stylesheet_ignores_non_whitelisted_pseudo_selectors() {
 	}
 
 	function test_get_stylesheet_handles_priority_of_elements_vs_block_elements_pseudo_selectors() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -414,7 +450,7 @@ function test_get_stylesheet_handles_priority_of_elements_vs_block_elements_pseu
 			)
 		);
 
-		$base_styles = 'body { margin: 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; }';
+		$base_styles = 'body{margin: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;}';
 
 		$element_styles = '.wp-block-group a:where(:not(.wp-element-button)){background-color: red;color: green;}.wp-block-group a:where(:not(.wp-element-button)):hover{background-color: green;color: red;font-size: 10em;text-transform: uppercase;}.wp-block-group a:where(:not(.wp-element-button)):focus{background-color: black;color: yellow;}';
 
@@ -425,6 +461,9 @@ function test_get_stylesheet_handles_priority_of_elements_vs_block_elements_pseu
 	}
 
 	function test_get_stylesheet_handles_whitelisted_block_level_element_pseudo_selectors() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -461,7 +500,7 @@ function test_get_stylesheet_handles_whitelisted_block_level_element_pseudo_sele
 			)
 		);
 
-		$base_styles = 'body { margin: 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; }';
+		$base_styles = 'body{margin: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;}';
 
 		$element_styles = 'a:where(:not(.wp-element-button)){background-color: red;color: green;}a:where(:not(.wp-element-button)):hover{background-color: green;color: red;}.wp-block-group a:where(:not(.wp-element-button)):hover{background-color: black;color: yellow;}';
 
@@ -480,6 +519,9 @@ function test_get_stylesheet_handles_whitelisted_block_level_element_pseudo_sele
 	 * remove that filter and instead use the core block for the following test.
 	 */
 	function test_get_stylesheet_with_block_support_feature_level_selectors() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version'  => WP_Theme_JSON_Gutenberg::LATEST_SCHEMA,
@@ -524,9 +566,9 @@ function test_get_stylesheet_with_block_support_feature_level_selectors() {
 			)
 		);
 
-		$base_styles   = 'body{--wp--preset--color--green: green;}body { margin: 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; }';
-		$block_styles  = '.wp-block-test, .wp-block-test__wrapper{color: green;}.wp-block-test .inner, .wp-block-test__wrapper .inner{border-radius: 9999px;padding: 20px;}.wp-block-test .sub-heading, .wp-block-test__wrapper .sub-heading{font-size: 3em;}';
-		$preset_styles = '.has-green-color{color: var(--wp--preset--color--green) !important;}.has-green-background-color{background-color: var(--wp--preset--color--green) !important;}.has-green-border-color{border-color: var(--wp--preset--color--green) !important;}';
+		$base_styles   = 'body{--wp--preset--color--green:green;margin: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;}';
+		$block_styles  = '.wp-block-test, .wp-block-test__wrapper{color:green;}.wp-block-test .inner, .wp-block-test__wrapper .inner{border-radius:9999px;padding:20px;}.wp-block-test .sub-heading, .wp-block-test__wrapper .sub-heading{font-size:3em;}';
+		$preset_styles = '.has-green-color{color:var(--wp--preset--color--green) !important;}.has-green-background-color{background-color:var(--wp--preset--color--green) !important;}.has-green-border-color{border-color:var(--wp--preset--color--green) !important;}';
 		$expected      = $base_styles . $block_styles . $preset_styles;
 
 		$this->assertEquals( $expected, $theme_json->get_stylesheet() );
@@ -598,6 +640,9 @@ function test_get_element_class_name_invalid() {
 	 * array( 'ref' => 'styles.color.background' ) => "#ffffff".
 	 */
 	function test_get_property_value_valid() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => 2,
@@ -618,7 +663,7 @@ function test_get_property_value_valid() {
 			)
 		);
 
-		$expected = 'body { margin: 0; }body{background-color: #ffffff;color: #000000;}.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; }.wp-element-button, .wp-block-button__link{background-color: #000000;color: #ffffff;}';
+		$expected = 'body{margin:0;background-color:#ffffff;color:#000000;}.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;}.wp-element-button, .wp-block-button__link{background-color:#000000;color:#ffffff;}';
 		$this->assertEquals( $expected, $theme_json->get_stylesheet() );
 	}
 
@@ -630,6 +675,9 @@ function test_get_property_value_valid() {
 	 * @expectedIncorrectUsage get_property_value
 	 */
 	function test_get_property_value_loop() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => 2,
@@ -650,7 +698,7 @@ function test_get_property_value_loop() {
 			)
 		);
 
-		$expected = 'body { margin: 0; }body{background-color: #ffffff;}.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; }.wp-element-button, .wp-block-button__link{color: #ffffff;}';
+		$expected = 'body{margin:0;background-color:#ffffff;}.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;}.wp-element-button, .wp-block-button__link{color:#ffffff;}';
 		$this->assertSame( $expected, $theme_json->get_stylesheet() );
 	}
 
@@ -661,6 +709,9 @@ function test_get_property_value_loop() {
 	 * @expectedIncorrectUsage get_property_value
 	 */
 	function test_get_property_value_recursion() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => 2,
@@ -681,7 +732,7 @@ function test_get_property_value_recursion() {
 			)
 		);
 
-		$expected = 'body { margin: 0; }body{background-color: #ffffff;color: #ffffff;}.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; }.wp-element-button, .wp-block-button__link{color: #ffffff;}';
+		$expected = 'body{margin:0;background-color:#ffffff;color:#ffffff;}.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;}.wp-element-button, .wp-block-button__link{color:#ffffff;}';
 		$this->assertEquals( $expected, $theme_json->get_stylesheet() );
 	}
 
@@ -692,6 +743,9 @@ function test_get_property_value_recursion() {
 	 * @expectedIncorrectUsage get_property_value
 	 */
 	function test_get_property_value_self() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => 2,
@@ -704,7 +758,7 @@ function test_get_property_value_self() {
 			)
 		);
 
-		$expected = 'body { margin: 0; }body{background-color: #ffffff;}.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; }';
+		$expected = 'body{margin:0;background-color:#ffffff;}.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;}';
 		$this->assertEquals( $expected, $theme_json->get_stylesheet() );
 	}
 
@@ -1007,6 +1061,9 @@ function data_generate_spacing_scale_fixtures() {
 	}
 
 	function test_get_styles_for_block_with_padding_aware_alignments() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version'  => 2,
@@ -1033,11 +1090,14 @@ function test_get_styles_for_block_with_padding_aware_alignments() {
 			'selector' => 'body',
 		);
 
-		$expected = 'body { margin: 0; }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;}.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 > .alignfull > :where([class*="wp-block-"]:not(.alignfull):not(.alignfull):not([class*="__"]),p,h1,h2,h3,h4,h5,h6,ul,ol) { padding-right: var(--wp--style--root--padding-right); padding-left: var(--wp--style--root--padding-left); }.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; }';
+		$expected = 'body{margin:0;--wp--style--root--padding-top:10px;--wp--style--root--padding-right:12px;--wp--style--root--padding-bottom:10px;--wp--style--root--padding-left:12px;}.wp-site-blocks{padding-top:var(--wp--style--root--padding-top);padding-bottom:var(--wp--style--root--padding-bottom);}.has-global-padding > .alignfull{margin-right:calc(var(--wp--style--root--padding-right) * -1);margin-left:calc(var(--wp--style--root--padding-left) * -1);}.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;}.has-global-padding,.has-global-padding > .alignfull > :where([class*="wp-block-"]:not(.alignfull):not(.alignfull):not([class*="__"]),p,h1,h2,h3,h4,h5,h6,ul,ol){padding-right:var(--wp--style--root--padding-right);padding-left:var(--wp--style--root--padding-left);}';
 		$this->assertEquals( $expected, $theme_json->get_styles_for_block( $metadata ) );
 	}
 
 	function test_get_styles_for_block_without_padding_aware_alignments() {
+		// Reset the Style-Engine stores for global-styles.
+		$this->reset_style_engine_stores();
+
 		$theme_json = new WP_Theme_JSON_Gutenberg(
 			array(
 				'version' => 2,
@@ -1061,7 +1121,7 @@ function test_get_styles_for_block_without_padding_aware_alignments() {
 			'selector' => 'body',
 		);
 
-		$expected = 'body { margin: 0; }body{padding-top: 10px;padding-right: 12px;padding-bottom: 10px;padding-left: 12px;}.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; }';
+		$expected = 'body{margin:0;padding-top:10px;padding-right:12px;padding-bottom:10px;padding-left:12px;}.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;}';
 		$this->assertEquals( $expected, $theme_json->get_styles_for_block( $metadata ) );
 	}
 }