diff --git a/gulpfile.js b/gulpfile.js
index 94b00421d..f00aec03d 100644
--- a/gulpfile.js
+++ b/gulpfile.js
@@ -571,15 +571,10 @@ exit;
 
 gulp.task( 'style-editor', function() {
 	return gulp.src( [ path.resolve( __dirname, './src/**/editor.scss' ), '!' + path.resolve( __dirname, './src/deprecated/**/editor.scss' ) ] )
-		// Override the breakpoints in the editor in
-		// src/styles/breakpoints.scss, we do it here because there are various
-		// files that use the breakpoints and it's easier to override it here.
+		// The active theme can change the editor preview widths at runtime.
+		// Use the editor's current device class rather than fixed Sass breakpoints.
 		.pipe( sassVariables( {
-			// Match the Block Editor's fixed preview widths. getMediaQuery subtracts 1,
-			// so these default values target 781px tablet and 479px mobile in WordPress 7.0.
-			// https://github.com/WordPress/gutenberg/pull/74339
-			'$desktop-width': 782,
-			'$tablet-width': 480,
+			'$use-editor-preview-classes': true,
 		} ) )
 		.pipe( sass( sassOptions ).on( 'error', sass.logError ) )
 		.pipe( concat( 'editor_blocks.css' ) )
diff --git a/src/components/block-css/index.js b/src/components/block-css/index.js
index 47956abd9..f43c24dfd 100644
--- a/src/components/block-css/index.js
+++ b/src/components/block-css/index.js
@@ -17,6 +17,7 @@ import {
 	getBlockUniqueClassname,
 	getDependencyAttrnamesFast,
 	getMediaQuery,
+	getViewportMediaQuery,
 	isVersionSupported,
 	prependClass,
 } from './util'
@@ -31,6 +32,7 @@ import {
  * External dependencies
  */
 import { pick, kebabCase } from 'lodash'
+import { settings } from 'stackable'
 
 /**
  * WordPress dependencies
@@ -546,7 +548,12 @@ function createCssEdit( selector, rule, value, device = 'desktop', vendorPrefixe
 		}
 	)
 
-	const mediaQuery = getMediaQuery( device, tabletBreakpoint, mobileBreakpoint )
+	const editorBreakpoints = settings.stackable_editor_breakpoints || {}
+	const mediaQuery = getViewportMediaQuery( device, settings.stackable_editor_viewport_breakpoints ) || getMediaQuery(
+		device,
+		editorBreakpoints.tablet || tabletBreakpoint,
+		editorBreakpoints.mobile || mobileBreakpoint
+	)
 	if ( mediaQuery ) {
 		css = `\n${ mediaQuery } {${ css }\n}`
 	}
diff --git a/src/components/block-css/util.js b/src/components/block-css/util.js
index 475d8968f..43990508f 100644
--- a/src/components/block-css/util.js
+++ b/src/components/block-css/util.js
@@ -33,7 +33,41 @@ export const getMediaQuery = ( devices = 'desktop', breakDesktop = 1024, breakTa
 	 } else if ( devices === 'mobile' ) {
 		 return '@media screen and (max-width: ' + ( breakTablet - 1 ) + 'px)'
 	 }
-	 return null
+	return null
+}
+
+/**
+ * Forms a media query string from WordPress theme.json viewport settings.
+ *
+ * WordPress 7.1 allows themes to configure these values and uses the same
+ * ranges for responsive editor previews. Unlike getMediaQuery, these are
+ * maximum viewport widths rather than the start of the next device range.
+ *
+ * @param {string} devices A list of devices: desktop, tablet or mobile.
+ * @param {Object} viewports WordPress viewport settings.
+ * @param {string} viewports.tablet Maximum Tablet viewport width.
+ * @param {string} viewports.mobile Maximum Mobile viewport width.
+ * @return {string|null} A media query, or null for missing settings.
+ */
+export const getViewportMediaQuery = ( devices = 'desktop', viewports = {} ) => {
+	const { tablet, mobile } = viewports
+	if ( ! tablet || ! mobile ) {
+		return null
+	}
+
+	if ( devices === 'desktopTablet' ) {
+		return `@media screen and (width > ${ mobile })`
+	} else if ( devices === 'desktopOnly' ) {
+		return `@media screen and (width > ${ tablet })`
+	} else if ( devices === 'tablet' ) {
+		return `@media screen and (width <= ${ tablet })`
+	} else if ( devices === 'tabletOnly' ) {
+		return `@media screen and (width > ${ mobile }) and (width <= ${ tablet })`
+	} else if ( devices === 'mobile' ) {
+		return `@media screen and (width <= ${ mobile })`
+	}
+
+	return null
 }
 
 /**
diff --git a/src/editor-settings.php b/src/editor-settings.php
index c07d859db..2604409b9 100644
--- a/src/editor-settings.php
+++ b/src/editor-settings.php
@@ -321,6 +321,22 @@ public function add_settings( $settings ) {
 			$settings['stackable_enable_heading_default_theme_margins_non_posts'] = get_option( 'stackable_enable_heading_default_theme_margins_non_posts' );
 			$settings['stackable_icon_list_block_default_icon'] = get_option( 'stackable_icon_list_block_default_icon' );
 
+			// WordPress 7.1 allows themes define the Tablet and Mobile editor preview
+			// breakpoints in theme.json. Keep Stackable's generated editor CSS in sync
+			// with those previews when the active theme provides valid values.
+			$viewport_breakpoints = function_exists( 'wp_get_global_settings' ) ? wp_get_global_settings( array( 'viewport' ) ) : array();
+			if (
+				is_array( $viewport_breakpoints ) &&
+				isset( $viewport_breakpoints['tablet'], $viewport_breakpoints['mobile'] ) &&
+				is_string( $viewport_breakpoints['tablet'] ) &&
+				is_string( $viewport_breakpoints['mobile'] )
+			) {
+				$settings['stackable_editor_viewport_breakpoints'] = array(
+					'tablet' => $viewport_breakpoints['tablet'],
+					'mobile' => $viewport_breakpoints['mobile'],
+				);
+			}
+
 			// Inserter variations are registered before the block Edit component renders,
 			// so provide the post type here.
 			$current_screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;
diff --git a/src/styles/breakpoints.scss b/src/styles/breakpoints.scss
index 472d4608e..2620a55b3 100644
--- a/src/styles/breakpoints.scss
+++ b/src/styles/breakpoints.scss
@@ -1,32 +1,75 @@
-// These breakpoints are also overridden by gulpfile.js when building styles for
-// the editor. We need to define these as integers here because in our
-// definition in gulpfile.js, we cannot use px.
+// The editor build uses its selected device class instead of viewport media
+// queries. The active theme controls the preview width at runtime, so Sass
+// cannot safely provide a fixed editor breakpoint.
 $desktop-width: 1024 !default;
 $tablet-width: 768 !default;
+$use-editor-preview-classes: false !default;
 
-@mixin desktop {
-	@media only screen and (min-width: #{$desktop-width + 0px}) {
+@mixin editor-preview-device( $device ) {
+	@at-root .stk-preview-device-#{ $device } #{ & } {
 		@content;
 	}
 }
+
+@mixin desktop {
+	@if $use-editor-preview-classes {
+		@include editor-preview-device( desktop ) {
+			@content;
+		}
+	} @else {
+		@media only screen and (min-width: #{$desktop-width + 0px}) {
+			@content;
+		}
+	}
+}
 @mixin desktop-tablet {
-	@media only screen and (min-width: #{$tablet-width + 0px}) {
-		@content;
+	@if $use-editor-preview-classes {
+		@include editor-preview-device( desktop ) {
+			@content;
+		}
+		@include editor-preview-device( tablet ) {
+			@content;
+		}
+	} @else {
+		@media only screen and (min-width: #{$tablet-width + 0px}) {
+			@content;
+		}
 	}
 }
 @mixin tablet {
-	@media only screen and (min-width: #{$tablet-width + 0px}) and (max-width: #{$desktop-width - 1px}) {
-		@content;
+	@if $use-editor-preview-classes {
+		@include editor-preview-device( tablet ) {
+			@content;
+		}
+	} @else {
+		@media only screen and (min-width: #{$tablet-width + 0px}) and (max-width: #{$desktop-width - 1px}) {
+			@content;
+		}
 	}
 }
 @mixin tablet-mobile {
-	@media only screen and (max-width: #{$desktop-width - 1px}) {
-		@content;
+	@if $use-editor-preview-classes {
+		@include editor-preview-device( tablet ) {
+			@content;
+		}
+		@include editor-preview-device( mobile ) {
+			@content;
+		}
+	} @else {
+		@media only screen and (max-width: #{$desktop-width - 1px}) {
+			@content;
+		}
 	}
 }
 @mixin mobile {
-	@media only screen and (max-width: #{$tablet-width - 1px}) {
-		@content;
+	@if $use-editor-preview-classes {
+		@include editor-preview-device( mobile ) {
+			@content;
+		}
+	} @else {
+		@media only screen and (max-width: #{$tablet-width - 1px}) {
+			@content;
+		}
 	}
 }
 
@@ -41,28 +84,31 @@ $tablet-width: 768 !default;
  * These dummy styles are removed by gulpfile.js in the `style-editor` and
  * `style` tasks.
  */
-@include desktop {
-	.z {
-		opacity: 1;
+
+@if not $use-editor-preview-classes {
+	@include desktop {
+		.z {
+			opacity: 1;
+		}
 	}
-}
-@include desktop-tablet {
-	.z {
-		opacity: 1;
+	@include desktop-tablet {
+		.z {
+			opacity: 1;
+		}
 	}
-}
-@include tablet {
-	.z {
-		opacity: 1;
+	@include tablet {
+		.z {
+			opacity: 1;
+		}
 	}
-}
-@include tablet-mobile {
-	.z {
-		opacity: 1;
+	@include tablet-mobile {
+		.z {
+			opacity: 1;
+		}
 	}
-}
-@include mobile {
-	.z {
-		opacity: 1;
+	@include mobile {
+		.z {
+			opacity: 1;
+		}
 	}
 }
diff --git a/src/styles/cssvars.scss b/src/styles/cssvars.scss
index 7af78941b..6d6954762 100644
--- a/src/styles/cssvars.scss
+++ b/src/styles/cssvars.scss
@@ -75,22 +75,38 @@ $_cssvars: ();
 		}
 
 		@if length( $tablet ) > 0 {
-			@include tablet {
-				:root {
+			@if $use-editor-preview-classes {
+				.stk-preview-device-tablet {
 					@each $name, $value in $tablet {
 						--stk-#{ $name }: #{ $value };
 					}
 				}
+			} @else {
+				@include tablet {
+					:root {
+						@each $name, $value in $tablet {
+							--stk-#{ $name }: #{ $value };
+						}
+					}
+				}
 			}
 		}
 
 		@if length( $mobile ) > 0 {
-			@include mobile {
-				:root {
+			@if $use-editor-preview-classes {
+				.stk-preview-device-mobile {
 					@each $name, $value in $mobile {
 						--stk-#{ $name }: #{ $value };
 					}
 				}
+			} @else {
+				@include mobile {
+					:root {
+						@each $name, $value in $mobile {
+							--stk-#{ $name }: #{ $value };
+						}
+					}
+				}
 			}
 		}
 	}