diff --git a/php-transformer/docs/form-presentation-graph.md b/php-transformer/docs/form-presentation-graph.md
new file mode 100644
index 000000000..3feefb1fe
--- /dev/null
+++ b/php-transformer/docs/form-presentation-graph.md
@@ -0,0 +1,25 @@
+# Form Presentation Graph
+
+`generic/computed-form-presentation/v2` is an optional `generic/forms/v1` payload member. It carries bounded source-CSS facts for controls, associated labels, and identified inline SVG descendants. It is not a provider recipe and never assigns visual semantics such as "globe" or "chevron".
+
+```php
+array{
+  schema: 'generic/computed-form-presentation/v2',
+  basis: 'source_css_cascade',
+  controls: list<array{index: int, control?: Role, label?: Role, required_marker?: Role}>,
+  visual_parts: list<array{
+    id: 'control-{control order}-svg-{descendant order}', index: int,
+    kind: 'inline_svg', source_selector: string, markup: safe-svg,
+    intrinsic_size?: array{width: positive-int, height: positive-int},
+    source_css: array{state: 'known', styles: array<string,string>, provenance: list<Provenance>}|array{state: 'unknown'}
+  }>,
+  variants: list<array{index: int, role: 'control'|'label'|'required_marker'|'visual_part', part_id?: string, condition: Condition, style_patch: array<string,string>, precedence: array<string,array>, provenance: list<Provenance>}>,
+  truncated: bool, limits: array{controls: 128, rules_per_role: 32}, diagnostics: list<string>
+}
+```
+
+`visual_parts` contains only drawable SVG descendants that pass `SourceDom::isSafeInlineSvgMarkup()`. `source_selector` identifies the source descendant and `index` links it to the source control order. `source_css.state: 'unknown'` means no unconditional source-CSS facts were matched. Responsive facts can still be present in `variants`; consumers evaluate those conditions rather than treating an unknown base as missing presentation. Consumers must not infer a role or layout from SVG shape or order.
+
+`required_marker` is emitted only for the existing explicit required marker identity: an `aria-hidden="true"` span containing one to four asterisks on a required control's associated label. It records the marker's own matched CSS and variants; when it inherits the label unchanged, it safely has empty `styles` and `provenance` rather than invented source facts. Existing v1 graphs remain valid. Graphs without visual parts or an explicit required marker retain the v1 envelope; graphs with either emit v2. This contract describes source appearance, not interaction-state semantics or provider destinations.
+
+The unshipped v2 envelope also includes `visual_groups`. Each group records the source selector of the SVG parts' lowest common ancestor, a stable `id`, ordered `part_ids`, and `source_css` using the same base-fact shape as visual parts. Group responsive variants use `role: visual_group` and `group_id` rather than a control index. Consumers preserve those authored container facts independently of each SVG's intrinsic dimensions and keep provider visibility state outside that layout container.
diff --git a/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php b/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php
index 74476bfbe..50106bde0 100644
--- a/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php
+++ b/php-transformer/src/ArtifactCompiler/ArtifactCompiler.php
@@ -2666,6 +2666,11 @@ private function stylesheetAssetsForSource(string $html, string $sourcePath, arr
                 if ( is_array($file) && ! isset($seenPaths[$file['path']]) ) {
                     $assets[] = array( 'path' => $file['path'], 'source_path' => $file['source_path'] ?? $file['path'], 'content' => $file['content'], 'source_hash' => (string) ($file['provenance']['hash'] ?? hash('sha256', $file['content']) ), 'media' => (string) ($file['media'] ?? ''), 'type' => (string) ($file['type'] ?? '') );
                     $seenPaths[$file['path']] = true;
+                } elseif ( '' !== ($content = trim(html_entity_decode($tagRecord['content'], ENT_QUOTES | ENT_HTML5, 'UTF-8'))) ) {
+                    // Generated inline-style files can be omitted at the artifact
+                    // file limit. Their source HTML was accepted independently,
+                    // so retain the authored stylesheet for source analysis.
+                    $assets[] = array( 'path' => 'inline-style-' . $inlineIndex . '.css', 'source_path' => 'inline-style', 'content' => $content, 'source_hash' => hash('sha256', $content), 'media' => $this->htmlAttribute($attributes, 'media'), 'type' => $this->htmlAttribute($attributes, 'type') );
                 }
                 continue;
             }
diff --git a/php-transformer/src/Css/CssAnalysisLimits.php b/php-transformer/src/Css/CssAnalysisLimits.php
new file mode 100644
index 000000000..bdafe7c35
--- /dev/null
+++ b/php-transformer/src/Css/CssAnalysisLimits.php
@@ -0,0 +1,11 @@
+<?php
+declare(strict_types=1);
+
+namespace Automattic\BlocksEngine\PhpTransformer\Css;
+
+/** Shared bounds for source-preserving CSS analysis consumers. */
+final class CssAnalysisLimits
+{
+    // Allows a complete author stylesheet while retaining a bounded parser input.
+    public const MAX_STYLESHEET_BYTES = 4194304;
+}
diff --git a/php-transformer/src/Css/CssRuleAnalyzer.php b/php-transformer/src/Css/CssRuleAnalyzer.php
index 0cc92a930..40ed88184 100644
--- a/php-transformer/src/Css/CssRuleAnalyzer.php
+++ b/php-transformer/src/Css/CssRuleAnalyzer.php
@@ -80,7 +80,7 @@ private function analyzeStylesheet(string $css, string $path, string $hash, ?arr
         for ( $offset = 0, $length = strlen($css); $offset < $length; ) {
             $boundary = $this->nextRuleBoundary($css, $offset);
             if ( null === $boundary ) {
-                if ( '' !== trim(substr($css, $offset)) ) {
+                if ( $this->hasNonTrivia($css, $offset) ) {
                     $result['diagnostics'][] = 'malformed_stylesheet:' . $path;
                 }
                 return;
@@ -249,6 +249,29 @@ private function nextRuleBoundary(string $css, int $offset): ?int
         return null;
     }
 
+    /**
+     * A stylesheet may legally end with whitespace and comments, including a
+     * source-map comment. Preserve malformed-input diagnostics for every other
+     * incomplete trailing token.
+     */
+    private function hasNonTrivia(string $css, int $offset): bool
+    {
+        $state = CssSyntaxScanner::state();
+        for ($length = strlen($css); $offset < $length; ) {
+            $insideComment = $state['comment'];
+            $startsComment = ! $insideComment && '' === $state['quote'] && '/*' === substr($css, $offset, 2);
+            $next = CssSyntaxScanner::consume($css, $offset, $state);
+            if ( null === $next ) {
+                return true;
+            }
+            if (! $insideComment && ! $startsComment && ! CssSyntaxScanner::isCssWhitespace($css[$offset])) {
+                return true;
+            }
+            $offset = $next;
+        }
+        return ! CssSyntaxScanner::isComplete($state);
+    }
+
     /**
      * CSS comments disappear from selectors, but adjacent identifier-like tokens
      * need a separator to avoid changing a descendant selector into one token.
diff --git a/php-transformer/src/HtmlToBlocks/Classification/SourceElementClassifier.php b/php-transformer/src/HtmlToBlocks/Classification/SourceElementClassifier.php
index 39e2a8b43..be2bb8639 100644
--- a/php-transformer/src/HtmlToBlocks/Classification/SourceElementClassifier.php
+++ b/php-transformer/src/HtmlToBlocks/Classification/SourceElementClassifier.php
@@ -278,7 +278,7 @@ public function isPositiveCssLength(string $value): bool
     public function isVisibleEmptyVisualPaint(string $value): bool
     {
         $value = strtolower(trim($value));
-        if ( '' === $value || 'none' === $value || 'transparent' === $value || preg_match('/^rgba?\([^)]*,\s*0(?:\.0+)?\s*\)$/', $value) ) {
+        if ( '' === $value || 'none' === $value || 'transparent' === $value || preg_match('/^0(?:px|%)?(?:\s+0(?:px|%)?)?$/', $value) || preg_match('/^rgba?\([^)]*,\s*0(?:\.0+)?\s*\)$/', $value) ) {
             return false;
         }
 
diff --git a/php-transformer/src/HtmlToBlocks/Elements/FormControlMetadataBuilder.php b/php-transformer/src/HtmlToBlocks/Elements/FormControlMetadataBuilder.php
index 7970eeb5f..ec34bd90f 100644
--- a/php-transformer/src/HtmlToBlocks/Elements/FormControlMetadataBuilder.php
+++ b/php-transformer/src/HtmlToBlocks/Elements/FormControlMetadataBuilder.php
@@ -109,14 +109,8 @@ public function control(DOMElement $control): array
 
         if ( $control->hasAttribute('required') || 'true' === strtolower(trim(SourceDom::attr($control, 'aria-required'))) ) {
             $metadata['required'] = true;
-            if ( $labelElement instanceof DOMElement ) {
-                foreach ( $labelElement->getElementsByTagName('span') as $marker ) {
-                    $text = trim($marker->textContent ?? '');
-                    if ( 'true' === strtolower(SourceDom::attr($marker, 'aria-hidden')) && preg_match('/^\*{1,4}$/D', $text) ) {
-                        $metadata['required_text'] = $text;
-                        break;
-                    }
-                }
+            if ( ($marker = $this->requiredMarker($control)) instanceof DOMElement ) {
+                $metadata['required_text'] = trim($marker->textContent ?? '');
             }
         }
         foreach ( array( 'disabled', 'readonly', 'checked', 'multiple' ) as $attribute ) {
@@ -192,6 +186,25 @@ public function associatedLabel(DOMElement $control): ?DOMElement
         return null;
     }
 
+    /** The explicit decorative required marker also supplies provider presentation identity. */
+    public function requiredMarker(DOMElement $control): ?DOMElement
+    {
+        if ( ! $control->hasAttribute('required') && 'true' !== strtolower(trim(SourceDom::attr($control, 'aria-required'))) ) {
+            return null;
+        }
+        $label = $this->labelElement($control);
+        if ( ! $label instanceof DOMElement ) {
+            return null;
+        }
+        foreach ( $label->getElementsByTagName('span') as $marker ) {
+            $text = trim($marker->textContent ?? '');
+            if ( 'true' === strtolower(SourceDom::attr($marker, 'aria-hidden')) && preg_match('/^\*{1,4}$/D', $text) ) {
+                return $marker;
+            }
+        }
+        return null;
+    }
+
     private function labelElement(DOMElement $control): ?DOMElement
     {
         $label = $this->associatedLabel($control);
diff --git a/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingBuilder.php b/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingBuilder.php
index f82791ae4..6e38fc8dd 100644
--- a/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingBuilder.php
+++ b/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingBuilder.php
@@ -31,7 +31,9 @@ public function build(DOMElement $element, ?array $readableFormBlock, ?array $bi
         $controlTopology = (new FormControlTopologyBuilder())->build($element);
         $layoutGraph = (new FormLayoutGraphBuilder())->build($element, $this->context->stylesheetAssets(), $this->context->formLayoutCss());
         $presentationGraph = (new FormPresentationGraphBuilder(
-            fn (DOMElement $control, string $value): string => $this->context->resolvePresentationValue($control, $value)
+            fn (DOMElement $control, string $value): string => $this->context->resolvePresentationValue($control, $value),
+            fn (DOMElement $element): string => $this->context->sanitizeInlineSvgMarkup($element),
+            fn (DOMElement $control): ?DOMElement => $this->metadataBuilder->requiredMarker($control)
         ))->build($element, $this->context->stylesheetAssets(), $this->context->formLayoutCss());
         $boundedHtml = $this->context->boundedFallbackHtml($element);
         $replacesRuntimeIsland = null !== $bindingBlock;
diff --git a/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingContext.php b/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingContext.php
index 4c630cac2..35cc5ddc5 100644
--- a/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingContext.php
+++ b/php-transformer/src/HtmlToBlocks/Elements/FormFallbackFindingContext.php
@@ -18,6 +18,7 @@ final class FormFallbackFindingContext
      * @param Closure(DOMElement): array<string, mixed>                                             $classifyFallbackSubtree
      * @param Closure(array<string, mixed>, string, array<int, string>): array<string, mixed>       $blockBinding
      * @param (Closure(DOMElement, string): string)|null                                            $resolvePresentationValue
+     * @param (Closure(DOMElement): string)|null                                                    $sanitizeInlineSvgMarkup
      */
     public function __construct(
         private readonly HtmlTransformerSession $session,
@@ -26,7 +27,8 @@ public function __construct(
         private readonly Closure $sourceContext,
         private readonly Closure $classifyFallbackSubtree,
         private readonly Closure $blockBinding,
-        private readonly ?Closure $resolvePresentationValue = null
+        private readonly ?Closure $resolvePresentationValue = null,
+        private readonly ?Closure $sanitizeInlineSvgMarkup = null
     ) {
     }
 
@@ -80,6 +82,11 @@ public function resolvePresentationValue(DOMElement $element, string $value): st
         return null !== $this->resolvePresentationValue ? ($this->resolvePresentationValue)($element, $value) : $value;
     }
 
+    public function sanitizeInlineSvgMarkup(DOMElement $element): string
+    {
+        return null !== $this->sanitizeInlineSvgMarkup ? ($this->sanitizeInlineSvgMarkup)($element) : '';
+    }
+
     /** @param array<string, mixed> $finding @return array<string, mixed> */
     public function buildFallbackDiagnostic(array $finding): array
     {
diff --git a/php-transformer/src/HtmlToBlocks/HtmlCompilation.php b/php-transformer/src/HtmlToBlocks/HtmlCompilation.php
index f5c2a7bf5..d732b76a7 100644
--- a/php-transformer/src/HtmlToBlocks/HtmlCompilation.php
+++ b/php-transformer/src/HtmlToBlocks/HtmlCompilation.php
@@ -617,7 +617,8 @@ function (DOMElement $element, array &$fallbacks, bool $captureUnsupported): arr
                 fn (DOMElement $element): array => $this->sourceContext($element),
                 fn (DOMElement $element): array => $this->fallbackEmitter()->classifyFallbackSubtree($element),
                 fn (array $block, string $role, array $supersededRuntimeSelectors): array => $this->blockBinding($block, $role, $supersededRuntimeSelectors),
-                fn (DOMElement $element, string $value): string => $this->styleResolver->resolveCssVariablesInValue($value, $element)
+                fn (DOMElement $element, string $value): string => $this->styleResolver->resolveCssVariablesInValue($value, $element),
+                fn (DOMElement $element): string => $this->svgMaterializer->restoreSvgCasing($this->sanitizeInlineSvgMarkup($element))
             ),
             $this->formControlMetadataBuilder,
             $this->formSuccessPanelMetadataBuilder,
@@ -1928,7 +1929,9 @@ private function materializeAuthorStylesheet(string $html, string $staticCss, bo
             // core Group and its children. Keep authored grid/flex children as
             // direct layout items, matching the saved frontend markup.
             $beforeAuthorCssParts[] = ':root :where(.' . self::CSS_OWNED_LAYOUT_CLASS . ')>.block-editor-inner-blocks,'
-                . ':root :where(.' . self::CSS_OWNED_LAYOUT_CLASS . ')>.block-editor-inner-blocks>.block-editor-block-list__layout{display:contents}';
+                . ':root :where(.' . self::CSS_OWNED_LAYOUT_CLASS . ')>.block-editor-inner-blocks>.block-editor-block-list__layout{display:contents}'
+                // Empty Group placeholders have an additional unadorned editor wrapper.
+                . ':root .editor-styles-wrapper :where(.' . self::CSS_OWNED_LAYOUT_CLASS . ')>div:not([class]):not([id]):not([style]):has(>[data-block].wp-block-group__placeholder){display:contents}';
         }
         $layoutShellBlockName = $this->generatedBlocks()->blockName('layout-shell');
         if ( str_contains($serializedBlocks, '<!-- wp:' . $layoutShellBlockName) ) {
diff --git a/php-transformer/src/HtmlToBlocks/Style/FormControlTopologyBuilder.php b/php-transformer/src/HtmlToBlocks/Style/FormControlTopologyBuilder.php
index eeec4a41f..9cd67e4a4 100644
--- a/php-transformer/src/HtmlToBlocks/Style/FormControlTopologyBuilder.php
+++ b/php-transformer/src/HtmlToBlocks/Style/FormControlTopologyBuilder.php
@@ -52,6 +52,38 @@ public function build(DOMElement $form): array
         );
     }
 
+    /**
+     * Return each control's nearest-to-farthest wrapper ancestors that contain no
+     * other form controls. Labels and other non-controls intentionally do not
+     * make a wrapper shared.
+     *
+     * @return array<int, list<DOMElement>>
+     */
+    public function exclusiveWrapperAncestors(DOMElement $form): array
+    {
+        $result = array();
+        $controls = $this->controls($form);
+        $owners = array();
+        foreach ( $controls as $control ) {
+            $depth = 0;
+            for ( $ancestor = $control->parentNode; $ancestor instanceof DOMElement && ! $ancestor->isSameNode($form) && $depth < self::MAX_DEPTH; $ancestor = $ancestor->parentNode, ++$depth ) {
+                $path = $ancestor->getNodePath();
+                $owners[$path] = ($owners[$path] ?? 0) + 1;
+            }
+        }
+        foreach ( $controls as $index => $control ) {
+            $ancestors = array();
+            $depth = 0;
+            for ( $ancestor = $control->parentNode; $ancestor instanceof DOMElement && ! $ancestor->isSameNode($form) && $depth < self::MAX_DEPTH; $ancestor = $ancestor->parentNode, ++$depth ) {
+                if ( 1 === ($owners[$ancestor->getNodePath()] ?? 0) ) {
+                    $ancestors[] = $ancestor;
+                }
+            }
+            $result[$index] = $ancestors;
+        }
+        return $result;
+    }
+
     /**
      * @param array<string, int> $controlIndexes
      * @param array<string, bool> $relevantElements
diff --git a/php-transformer/src/HtmlToBlocks/Style/FormCustomPropertyResolver.php b/php-transformer/src/HtmlToBlocks/Style/FormCustomPropertyResolver.php
new file mode 100644
index 000000000..84d525517
--- /dev/null
+++ b/php-transformer/src/HtmlToBlocks/Style/FormCustomPropertyResolver.php
@@ -0,0 +1,143 @@
+<?php
+declare(strict_types=1);
+
+namespace Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style;
+
+use Automattic\BlocksEngine\PhpTransformer\Css\CssSelectorMatcher;
+use Automattic\BlocksEngine\PhpTransformer\Css\CssRuleAnalyzer;
+use DOMElement;
+
+/** Resolves bounded custom-property rules at a form element's cascade scope. */
+final class FormCustomPropertyResolver
+{
+    private const MAX_EXPANSION_DEPTH = 5;
+    private const MAX_EXPANDED_BYTES = 4096;
+
+    /** @param list<array<string, mixed>> $rules */
+    public static function resolve(string $value, DOMElement $element, ?array $condition, array $rules): string
+    {
+        if ( ! str_contains($value, 'var(') ) {
+            return trim($value);
+        }
+        $properties = array();
+        $ancestors = array();
+        for ( $current = $element; $current instanceof DOMElement; $current = $current->parentNode instanceof DOMElement ? $current->parentNode : null ) {
+            $ancestors[] = $current;
+        }
+        foreach ( array_reverse($ancestors) as $ancestor ) {
+            // Cascade each element before applying its declarations over inherited values.
+            $declared = array();
+            foreach ( $rules as $rule ) {
+                // A conditional cascade inherits its base custom properties while excluding other conditions.
+                if ( ( null !== ($rule['condition'] ?? null) && ($rule['condition'] ?? null) !== $condition ) || ! CssSelectorMatcher::matches($ancestor, $rule['parsed_selector'])['matches'] ) {
+                    continue;
+                }
+                foreach ( $rule['declarations'] as $declaration ) {
+                    if ( ! str_starts_with($declaration['name'], '--') ) {
+                        continue;
+                    }
+                    $declarationValue = preg_replace('/\s*!important\s*$/i', '', $declaration['value']) ?? $declaration['value'];
+                    CssCascade::apply($declared, $declaration['name'], array( 'value' => $declarationValue, 'order' => $rule['order'], 'specificity' => $rule['specificity'], 'important' => 1 === preg_match('/\s*!important\s*$/i', $declaration['value']) ));
+                }
+            }
+            if ( $ancestor->hasAttribute('style') ) {
+                $inline = $ancestor->getAttribute('style');
+                foreach ( CssRuleAnalyzer::declarations($inline, array('--*')) as $declaration ) {
+                    $declarationValue = preg_replace('/\s*!important\s*$/i', '', $declaration['value']) ?? $declaration['value'];
+                    CssCascade::apply($declared, $declaration['name'], array( 'value' => $declarationValue, 'order' => PHP_INT_MAX, 'specificity' => PHP_INT_MAX, 'important' => 1 === preg_match('/\s*!important\s*$/i', $declaration['value']) ));
+                }
+            }
+            // Custom-property values are computed where they are declared. A
+            // descendant override must not alter an already inherited value.
+            $inherited = array_map(static fn (array $fact): string => $fact['value'], $properties);
+            foreach ( self::computed($declared, $inherited) as $name => $computedValue ) {
+                if ( null === $computedValue ) {
+                    unset($properties[$name]);
+                    continue;
+                }
+                $properties[$name] = $declared[$name] + array( 'value' => $computedValue );
+                $properties[$name]['value'] = $computedValue;
+            }
+        }
+        $customProperties = array_map(static fn (array $fact): string => $fact['value'], $properties);
+        return self::expandWith($value, static fn (string $name): ?string => $customProperties[$name] ?? null) ?? trim($value);
+    }
+
+    /** @param list<array<string, mixed>> $rules @return list<array<string, mixed>> */
+    public static function conditionsChanging(string $value, DOMElement $element, array $rules): array
+    {
+        if ( ! str_contains($value, 'var(') ) {
+            return array();
+        }
+        $base = self::resolve($value, $element, null, $rules);
+        $conditions = array();
+        foreach ( $rules as $rule ) {
+            $condition = $rule['condition'] ?? null;
+            if ( null === $condition ) {
+                continue;
+            }
+            $matchesAncestor = false;
+            for ( $ancestor = $element; $ancestor instanceof DOMElement; $ancestor = $ancestor->parentNode instanceof DOMElement ? $ancestor->parentNode : null ) {
+                if ( CssSelectorMatcher::matches($ancestor, $rule['parsed_selector'])['matches'] ) {
+                    $matchesAncestor = true;
+                    break;
+                }
+            }
+            if ( ! $matchesAncestor ) continue;
+            $key = json_encode($condition);
+            if ( ! isset($conditions[$key]) && self::resolve($value, $element, $condition, $rules) !== $base ) {
+                $conditions[$key] = $condition;
+            }
+        }
+        return array_values($conditions);
+    }
+
+    /** @param array<string, array<string, mixed>> $declared @param array<string, string> $inherited @return array<string, string|null> */
+    private static function computed(array $declared, array $inherited): array
+    {
+        $computed = array();
+        $resolving = array();
+        $invalid = array();
+        $resolve = null;
+        $resolve = static function (string $name, int $depth = 0) use (&$resolve, &$computed, &$resolving, &$invalid, $declared, $inherited): ?string {
+            if ( array_key_exists($name, $computed) ) return $computed[$name];
+            if ( ! isset($declared[$name]) ) return $inherited[$name] ?? null;
+            if ( $depth >= self::MAX_EXPANSION_DEPTH || isset($resolving[$name]) ) {
+                foreach ( array_keys($resolving) as $resolvingName ) $invalid[$resolvingName] = true;
+                $invalid[$name] = true;
+                return null;
+            }
+            $resolving[$name] = true;
+            $value = self::expandWith($declared[$name]['value'], static fn (string $reference): ?string => $resolve($reference, $depth + 1));
+            unset($resolving[$name]);
+            if ( isset($invalid[$name]) ) $value = null;
+            $computed[$name] = $value;
+            return $value;
+        };
+        foreach ( array_keys($declared) as $name ) $resolve($name);
+        return $computed;
+    }
+
+    /** @param callable(string): ?string $resolve */
+    private static function expandWith(string $value, callable $resolve): ?string
+    {
+        $seen = array();
+        for ( $pass = 0; $pass < self::MAX_EXPANSION_DEPTH && str_contains($value, 'var('); ++$pass ) {
+            if ( strlen($value) > self::MAX_EXPANDED_BYTES ) return null;
+            if ( isset($seen[$value]) ) return null;
+            $seen[$value] = true;
+            $unresolved = false;
+            $expanded = preg_replace_callback('/var\(\s*(--[A-Za-z0-9_-]+)\s*(?:,\s*([^()]*))?\)/', static function (array $matches) use ($resolve, &$unresolved): string {
+                $resolved = $resolve($matches[1]);
+                if ( null !== $resolved ) return $resolved;
+                if ( isset($matches[2]) ) return trim($matches[2]);
+                $unresolved = true;
+                return $matches[0];
+            }, $value);
+            if ( ! is_string($expanded) || $unresolved ) return null;
+            if ( $expanded === $value ) break;
+            $value = $expanded;
+        }
+        return str_contains($value, 'var(') || strlen($value) > self::MAX_EXPANDED_BYTES ? null : trim($value);
+    }
+}
diff --git a/php-transformer/src/HtmlToBlocks/Style/FormLayoutGraphBuilder.php b/php-transformer/src/HtmlToBlocks/Style/FormLayoutGraphBuilder.php
index 970fc8b24..161f12827 100644
--- a/php-transformer/src/HtmlToBlocks/Style/FormLayoutGraphBuilder.php
+++ b/php-transformer/src/HtmlToBlocks/Style/FormLayoutGraphBuilder.php
@@ -3,6 +3,7 @@
 
 namespace Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style;
 
+use Automattic\BlocksEngine\PhpTransformer\Css\CssAnalysisLimits;
 use Automattic\BlocksEngine\PhpTransformer\Css\CssRuleAnalyzer;
 use Automattic\BlocksEngine\PhpTransformer\Css\CssSelectorMatcher;
 use Automattic\BlocksEngine\PhpTransformer\Css\CssValueSplitter;
@@ -16,7 +17,6 @@ final class FormLayoutGraphBuilder
     private const MAX_NODES = 128;
     private const MAX_DEPTH = 16;
     private const MAX_RULES_PER_NODE = 16;
-    private const MAX_CSS_BYTES = 262144;
     private const MAX_RULES = 512;
     private const MAX_SELECTORS = 1024;
     // Parsing work and retained cascade candidates have independent bounds.
@@ -48,13 +48,13 @@ public function build(DOMElement $form, array $stylesheets, string $inlineCss =
 
         $entries = array();
         $wrapper = 0;
-        // The form root is outside the topology depth coordinate; its children are depth zero.
+        // The graph root is outside the topology depth coordinate; its children are depth zero.
         $this->collect($form, null, 0, -1, $controls, $relevant, $entries, $wrapper);
         $analysis = (new CssRuleAnalyzer())->analyze(
             $stylesheets,
             $inlineCss,
             self::PROPERTIES,
-            self::MAX_CSS_BYTES,
+            CssAnalysisLimits::MAX_STYLESHEET_BYTES,
             self::MAX_RULES,
             self::MAX_SELECTORS,
             self::MAX_CONDITION_DEPTH,
@@ -71,12 +71,43 @@ static function (array $selector) use ($entries): bool {
         );
         $this->diagnostics = array_merge($this->diagnostics, $analysis['diagnostics']);
         $this->truncated = $this->truncated || $analysis['truncated'];
+        $customPropertyAnalysis = (new CssRuleAnalyzer())->analyze(
+            $stylesheets,
+            $inlineCss,
+            array('--*'),
+            CssAnalysisLimits::MAX_STYLESHEET_BYTES,
+            self::MAX_RULES,
+            self::MAX_SELECTORS,
+            self::MAX_CONDITION_DEPTH,
+            static function (array $selector) use ($entries): bool {
+                foreach ( $entries as $entry ) {
+                    for ( $ancestor = $entry['element']; $ancestor instanceof DOMElement; $ancestor = $ancestor->parentNode instanceof DOMElement ? $ancestor->parentNode : null ) {
+                        if ( CssSelectorMatcher::matches($ancestor, $selector)['matches'] ) {
+                            return true;
+                        }
+                    }
+                }
+                return false;
+            },
+            self::MAX_SCANNED_SELECTORS
+        );
+        $this->diagnostics = array_merge($this->diagnostics, $customPropertyAnalysis['diagnostics']);
+        $this->truncated = $this->truncated || $customPropertyAnalysis['truncated'];
         $nodes = array();
         $variants = array();
         foreach ( $entries as $entry ) {
             $matched = $this->matched($entry['element'], $analysis['rules']);
-            $layout = $this->layout($matched['base']);
+            $layout = $this->layout($matched['base'], $entry['element'], null, $customPropertyAnalysis['rules']);
             $conditional = $this->effectiveConditional($matched['conditional'], $matched['base']);
+            foreach ( $matched['base'] as $property => $fact ) {
+                foreach ( FormCustomPropertyResolver::conditionsChanging($fact['value'], $entry['element'], $customPropertyAnalysis['rules']) as $condition ) {
+                    $encoded = json_encode($condition);
+                    if ( ! isset($conditional[$encoded][$property]) ) {
+                        $this->truncated = true;
+                        $this->diagnostics[] = 'conditional_custom_property_layout';
+                    }
+                }
+            }
             if ( array() === $layout && array() === $conditional ) {
                 continue;
             }
@@ -89,7 +120,7 @@ static function (array $selector) use ($entries): bool {
                     break;
                 }
                 $condition = json_decode($encoded, true);
-                $patch = $this->layout($facts);
+                $patch = $this->layout($facts, $entry['element'], $condition, $customPropertyAnalysis['rules']);
                 if ( array() !== $patch ) {
                     $variants[] = array( 'node' => $entry['id'], 'condition' => $condition, 'layout_patch' => $patch, 'precedence' => $this->precedence($facts), 'provenance' => $this->provenance($facts, $condition) );
                 }
@@ -249,7 +280,7 @@ private static function validSizing(array $node, array $sizing, array $nodes): b
     private function collect(DOMElement $element, ?string $parent, int $order, int $depth, array $controls, array $relevant, array &$entries, int &$wrapper): void
     {
         $path = $element->getNodePath();
-        $root = 'form' === strtolower($element->tagName) && null === $parent;
+        $root = null === $parent;
         if ( ! $root && ! isset($controls[$path]) && ! isset($relevant[$path]) ) {
             return;
         }
@@ -359,11 +390,11 @@ private function matched(DOMElement $element, array $rules): array
     }
 
     /** @return array<string, string> */
-    private function layout(array $facts): array
+    private function layout(array $facts, DOMElement $element, ?array $condition, array $customPropertyRules): array
     {
         $result = array();
         foreach ( $facts as $property => $fact ) {
-            $result[self::layoutKey($property)] = $fact['value'];
+            $result[self::layoutKey($property)] = FormCustomPropertyResolver::resolve($fact['value'], $element, $condition, $customPropertyRules);
         }
         ksort($result);
         return $result;
diff --git a/php-transformer/src/HtmlToBlocks/Style/FormPresentationGraphBuilder.php b/php-transformer/src/HtmlToBlocks/Style/FormPresentationGraphBuilder.php
index a402a6bfd..056c45c48 100644
--- a/php-transformer/src/HtmlToBlocks/Style/FormPresentationGraphBuilder.php
+++ b/php-transformer/src/HtmlToBlocks/Style/FormPresentationGraphBuilder.php
@@ -3,8 +3,11 @@
 
 namespace Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style;
 
+use Automattic\BlocksEngine\PhpTransformer\Css\CssAnalysisLimits;
 use Automattic\BlocksEngine\PhpTransformer\Css\CssRuleAnalyzer;
 use Automattic\BlocksEngine\PhpTransformer\Css\CssSelectorMatcher;
+use Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Classification\SourceElementClassifier;
+use Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Support\SourceDom;
 use Automattic\BlocksEngine\PhpTransformer\Path\ArtifactPath;
 use Closure;
 use DOMDocument;
@@ -16,13 +19,22 @@ final class FormPresentationGraphBuilder
 {
     private const MAX_CONTROLS = 128;
     private const MAX_RULES_PER_ROLE = 32;
-    private const MAX_CSS_BYTES = 4194304;
     private const MAX_RULES = 8192;
     private const MAX_SELECTORS = 16384;
     private const MAX_CONDITION_DEPTH = 8;
     private const MAX_VARIANTS = 256;
+    private const MAX_VISUAL_PARTS = 32;
+    private const MAX_VISUAL_BYTES = 12288;
+    private const MAX_VISUAL_DIMENSION = 4096;
     private const MAX_PROVENANCE = 16;
     private const MAX_DIAGNOSTICS = 32;
+    private const CONTROL_CONTAINER_PROPERTIES = array(
+        'background', 'background-color', 'border', 'border-color', 'border-style', 'border-width',
+        'border-top-color', 'border-right-color', 'border-bottom-color', 'border-left-color',
+        'border-top-style', 'border-right-style', 'border-bottom-style', 'border-left-style',
+        'border-top-width', 'border-right-width', 'border-bottom-width', 'border-left-width',
+        'border-radius', 'border-top-left-radius', 'border-top-right-radius', 'border-bottom-right-radius', 'border-bottom-left-radius',
+    );
     private const PROPERTIES = array(
         'appearance', 'background', 'background-color', 'border', 'border-color', 'border-style', 'border-width',
         'border-top-color', 'border-right-color', 'border-bottom-color', 'border-left-color',
@@ -33,14 +45,17 @@ final class FormPresentationGraphBuilder
         'height', 'letter-spacing', 'line-height', 'margin', 'margin-top', 'margin-right', 'margin-bottom', 'margin-left',
         'max-width', 'min-height', 'min-width', 'padding', 'padding-top', 'padding-right', 'padding-bottom', 'padding-left',
         'padding-block-start', 'padding-block-end', 'padding-inline-start', 'padding-inline-end',
-        'text-align', 'text-decoration', 'text-indent', 'text-transform', 'vertical-align', 'width'
+        'text-align', 'text-decoration', 'text-indent', 'text-transform', 'vertical-align', 'width',
+        'align-self', 'bottom', 'flex', 'flex-basis', 'flex-grow', 'flex-shrink', 'inset', 'justify-self',
+        'left', 'margin-block', 'margin-inline', 'order', 'position', 'right', 'top', 'transform', 'z-index',
+        'flex-direction', 'align-items', 'justify-content', 'gap'
     );
 
     private array $diagnostics = array();
     private bool $truncated = false;
 
-    /** @param (Closure(DOMElement, string): string)|null $resolveValue */
-    public function __construct(private readonly ?Closure $resolveValue = null)
+    /** @param (Closure(DOMElement, string): string)|null $resolveValue @param (Closure(DOMElement): string)|null $sanitizeInlineSvgMarkup @param (Closure(DOMElement): ?DOMElement)|null $requiredMarker */
+    public function __construct(private readonly ?Closure $resolveValue = null, private readonly ?Closure $sanitizeInlineSvgMarkup = null, private readonly ?Closure $requiredMarker = null)
     {
     }
 
@@ -49,13 +64,13 @@ public function build(DOMElement $form, array $stylesheets, string $inlineCss =
     {
         $this->diagnostics = array();
         $this->truncated = false;
-        $analysis = (new CssRuleAnalyzer())->analyze($stylesheets, $inlineCss, self::PROPERTIES, self::MAX_CSS_BYTES, self::MAX_RULES, self::MAX_SELECTORS, self::MAX_CONDITION_DEPTH);
-        $controlsForCustomProperties = $this->controls($form);
+        $analysis = (new CssRuleAnalyzer())->analyze($stylesheets, $inlineCss, self::PROPERTIES, CssAnalysisLimits::MAX_STYLESHEET_BYTES, self::MAX_RULES, self::MAX_SELECTORS, self::MAX_CONDITION_DEPTH);
+        $controlsForCustomProperties = $this->presentationElements($form);
         $customPropertyAnalysis = (new CssRuleAnalyzer())->analyze(
             $stylesheets,
             $inlineCss,
             array('--*'),
-            self::MAX_CSS_BYTES,
+            CssAnalysisLimits::MAX_STYLESHEET_BYTES,
             self::MAX_RULES,
             self::MAX_SELECTORS,
             self::MAX_CONDITION_DEPTH,
@@ -72,6 +87,11 @@ function (array $selector) use ($controlsForCustomProperties): bool {
         $this->truncated = $analysis['truncated'];
         $controls = array();
         $variants = array();
+        $visualParts = array();
+        $visualGroups = array();
+        $hasRequiredMarker = false;
+        $controlContainers = array();
+        $exclusiveAncestors = (new FormControlTopologyBuilder())->exclusiveWrapperAncestors($form);
 
         foreach ( $this->controls($form) as $index => $control ) {
             if ( $index >= self::MAX_CONTROLS ) {
@@ -80,13 +100,18 @@ function (array $selector) use ($controlsForCustomProperties): bool {
                 break;
             }
             $row = array( 'index' => $index );
-            foreach ( array( 'control' => $control, 'label' => $this->label($control) ) as $role => $element ) {
+            $roles = array( 'control' => $control, 'label' => $this->label($control) );
+            if ( null !== $this->requiredMarker && ($marker = ($this->requiredMarker)($control)) instanceof DOMElement ) {
+                $roles['required_marker'] = $marker;
+                $hasRequiredMarker = true;
+            }
+            foreach ( $roles as $role => $element ) {
                 if ( ! $element instanceof DOMElement ) {
                     continue;
                 }
                 $matched = $this->matched($element, $analysis['rules']);
                 $styles = $this->styles($matched['base'], $element, null, $customPropertyAnalysis['rules']);
-                if ( array() !== $styles ) {
+                if ( array() !== $styles || 'required_marker' === $role ) {
                     $row[$role] = array( 'styles' => $styles, 'provenance' => $this->provenance($matched['base'], null) );
                 }
                 foreach ( $this->effectiveConditional($matched['conditional'], $matched['base']) as $encoded => $facts ) {
@@ -109,13 +134,50 @@ function (array $selector) use ($controlsForCustomProperties): bool {
                     }
                 }
             }
+            $container = $this->controlContainer($index, $exclusiveAncestors[$index] ?? array(), $analysis['rules'], $customPropertyAnalysis['rules']);
+            if ( null !== $container ) {
+                $controlContainers[] = $container['container'];
+                foreach ( $container['variants'] as $variant ) {
+                    if ( count($variants) >= self::MAX_VARIANTS ) { $this->truncated = true; $this->diagnostics[] = 'variant_limit'; break 2; }
+                    $variants[] = $variant;
+                }
+            }
+            $capturedParts = $this->visualParts($control, $index, $analysis['rules'], $customPropertyAnalysis['rules']);
+            foreach ( $capturedParts as $part ) {
+                if ( count($visualParts) >= self::MAX_VISUAL_PARTS ) {
+                    $this->truncated = true;
+                    $this->diagnostics[] = 'visual_part_limit';
+                    break;
+                }
+                $visualParts[] = $part['part'];
+                foreach ( $part['variants'] as $variant ) {
+                    if ( count($variants) >= self::MAX_VARIANTS ) {
+                        $this->truncated = true;
+                        $this->diagnostics[] = 'variant_limit';
+                        break 2;
+                    }
+                    $variants[] = $variant;
+                }
+            }
+            $visualGroup = $capturedParts === array() ? null : $capturedParts[array_key_last($capturedParts)];
+            if ( isset($visualGroup['group']) && array() === array_diff($visualGroup['group']['part_ids'], array_column($visualParts, 'id')) ) {
+                $visualGroups[] = $visualGroup['group'];
+                foreach ( $visualGroup['group_variants'] as $variant ) {
+                    if ( count($variants) >= self::MAX_VARIANTS ) {
+                        $this->truncated = true;
+                        $this->diagnostics[] = 'variant_limit';
+                        break 2;
+                    }
+                    $variants[] = $variant;
+                }
+            }
             if ( count($row) > 1 ) {
                 $controls[] = $row;
             }
         }
 
         $graph = array(
-            'schema' => 'generic/computed-form-presentation/v1',
+            'schema' => array() === $visualParts && ! $hasRequiredMarker && array() === $controlContainers ? 'generic/computed-form-presentation/v1' : 'generic/computed-form-presentation/v2',
             'basis' => 'source_css_cascade',
             'truncated' => $this->truncated,
             'limits' => array( 'controls' => self::MAX_CONTROLS, 'rules_per_role' => self::MAX_RULES_PER_ROLE ),
@@ -123,6 +185,11 @@ function (array $selector) use ($controlsForCustomProperties): bool {
             'variants' => $variants,
             'diagnostics' => array_slice(array_values(array_unique($this->diagnostics)), 0, self::MAX_DIAGNOSTICS),
         );
+        if ( 'generic/computed-form-presentation/v2' === $graph['schema'] ) {
+            $graph['visual_parts'] = $visualParts;
+            $graph['visual_groups'] = $visualGroups;
+            $graph['control_containers'] = $controlContainers;
+        }
         self::assertValid($graph);
         return $graph;
     }
@@ -130,38 +197,122 @@ function (array $selector) use ($controlsForCustomProperties): bool {
     /** @param array<string, mixed> $graph */
     public static function assertValid(array $graph): void
     {
-        if ( 'generic/computed-form-presentation/v1' !== ($graph['schema'] ?? null) || 'source_css_cascade' !== ($graph['basis'] ?? null) || ! is_bool($graph['truncated'] ?? null) || ! is_array($graph['limits'] ?? null) || array_diff(array_keys($graph['limits']), array( 'controls', 'rules_per_role' )) || self::MAX_CONTROLS !== ($graph['limits']['controls'] ?? null) || self::MAX_RULES_PER_ROLE !== ($graph['limits']['rules_per_role'] ?? null) || ! is_array($graph['controls'] ?? null) || ! array_is_list($graph['controls']) || count($graph['controls']) > self::MAX_CONTROLS || ! is_array($graph['variants'] ?? null) || ! array_is_list($graph['variants']) || count($graph['variants']) > self::MAX_VARIANTS || ! is_array($graph['diagnostics'] ?? null) || ! array_is_list($graph['diagnostics']) || count($graph['diagnostics']) > self::MAX_DIAGNOSTICS || array_filter($graph['diagnostics'], static fn (mixed $diagnostic): bool => ! is_string($diagnostic) || '' === trim($diagnostic) || strlen($diagnostic) > 1100) || array_diff(array_keys($graph), array( 'schema', 'basis', 'truncated', 'limits', 'controls', 'variants', 'diagnostics' )) ) {
+        $version = $graph['schema'] ?? null;
+        $v1 = 'generic/computed-form-presentation/v1' === $version;
+        $v2 = 'generic/computed-form-presentation/v2' === $version;
+        $expectedKeys = $v2 ? array( 'schema', 'basis', 'truncated', 'limits', 'controls', 'visual_parts', 'visual_groups', 'control_containers', 'variants', 'diagnostics' ) : array( 'schema', 'basis', 'truncated', 'limits', 'controls', 'variants', 'diagnostics' );
+        if ( (! $v1 && ! $v2) || 'source_css_cascade' !== ($graph['basis'] ?? null) || ! is_bool($graph['truncated'] ?? null) || ! is_array($graph['limits'] ?? null) || array_diff(array_keys($graph['limits']), array( 'controls', 'rules_per_role' )) || self::MAX_CONTROLS !== ($graph['limits']['controls'] ?? null) || self::MAX_RULES_PER_ROLE !== ($graph['limits']['rules_per_role'] ?? null) || ! is_array($graph['controls'] ?? null) || ! array_is_list($graph['controls']) || count($graph['controls']) > self::MAX_CONTROLS || ($v2 && (! is_array($graph['visual_parts'] ?? null) || ! array_is_list($graph['visual_parts']) || count($graph['visual_parts']) > self::MAX_VISUAL_PARTS || ! is_array($graph['visual_groups'] ?? null) || ! array_is_list($graph['visual_groups']) || count($graph['visual_groups']) > self::MAX_VISUAL_PARTS || ! is_array($graph['control_containers'] ?? null) || ! array_is_list($graph['control_containers']) || count($graph['control_containers']) > self::MAX_CONTROLS)) || ! is_array($graph['variants'] ?? null) || ! array_is_list($graph['variants']) || count($graph['variants']) > self::MAX_VARIANTS || ! is_array($graph['diagnostics'] ?? null) || ! array_is_list($graph['diagnostics']) || count($graph['diagnostics']) > self::MAX_DIAGNOSTICS || array_filter($graph['diagnostics'], static fn (mixed $diagnostic): bool => ! is_string($diagnostic) || '' === trim($diagnostic) || strlen($diagnostic) > 1100) || array_diff(array_keys($graph), $expectedKeys) ) {
             throw new InvalidArgumentException('Form presentation graph envelope is invalid.');
         }
+        $containerIndexes = array();
+        foreach ( $v2 ? $graph['control_containers'] : array() as $container ) {
+            if ( ! is_array($container) || array_diff(array_keys($container), array( 'index', 'source_selector', 'styles', 'provenance' )) || ! is_int($container['index'] ?? null) || $container['index'] < 0 || $container['index'] >= self::MAX_CONTROLS || isset($containerIndexes[$container['index']]) || ! is_string($container['source_selector'] ?? null) || '' === trim($container['source_selector']) || strlen($container['source_selector']) > 2048 || ! is_array($container['styles'] ?? null) || array_diff(array_keys($container['styles']), array_map(self::key(...), self::CONTROL_CONTAINER_PROPERTIES)) || ! is_array($container['provenance'] ?? null) ) throw new InvalidArgumentException('Form presentation control container is invalid.');
+            self::assertStyles($container['styles']); self::assertProvenance($container['provenance'], $container['styles'], null);
+            $containerIndexes[$container['index']] = array() !== $container['styles'];
+        }
         $seen = array();
         foreach ( $graph['controls'] as $row ) {
-            if ( ! is_array($row) || array_diff(array_keys($row), array( 'index', 'control', 'label' )) || ! is_int($row['index'] ?? null) || $row['index'] < 0 || $row['index'] >= self::MAX_CONTROLS || isset($seen[$row['index']]) || (! isset($row['control']) && ! isset($row['label'])) ) {
+            if ( ! is_array($row) || array_diff(array_keys($row), $v2 ? array( 'index', 'control', 'label', 'required_marker' ) : array( 'index', 'control', 'label' )) || ! is_int($row['index'] ?? null) || $row['index'] < 0 || $row['index'] >= self::MAX_CONTROLS || isset($seen[$row['index']]) || (! isset($row['control']) && ! isset($row['label']) && ! isset($row['required_marker'])) ) {
                 throw new InvalidArgumentException('Form presentation control is invalid.');
             }
             $seen[$row['index']] = true;
-            foreach ( array( 'control', 'label' ) as $role ) {
-                if ( isset($row[$role]) ) self::assertRole($row[$role], null);
+            foreach ( $v2 ? array( 'control', 'label', 'required_marker' ) : array( 'control', 'label' ) as $role ) {
+                if ( isset($row[$role]) ) self::assertRole($row[$role], null, 'required_marker' === $role);
             }
         }
+        $partIds = array();
+        foreach ( $v2 ? $graph['visual_parts'] : array() as $part ) {
+            self::assertVisualPart($part);
+            if ( isset($partIds[$part['id']]) ) throw new InvalidArgumentException('Form presentation visual part identity is duplicated.');
+            $partIds[$part['id']] = $part['index'];
+        }
+        $groupIds = array();
+        foreach ( $v2 ? $graph['visual_groups'] : array() as $group ) {
+            self::assertVisualGroup($group, $partIds);
+            if ( isset($groupIds[$group['id']]) ) throw new InvalidArgumentException('Form presentation visual group identity is duplicated.');
+            $groupIds[$group['id']] = true;
+        }
+        $containerVariants = array();
         foreach ( $graph['variants'] as $variant ) {
-            if ( ! is_array($variant) || array_diff(array_keys($variant), array( 'index', 'role', 'condition', 'style_patch', 'precedence', 'provenance' )) || ! is_int($variant['index'] ?? null) || $variant['index'] < 0 || $variant['index'] >= self::MAX_CONTROLS || ! in_array($variant['role'] ?? null, array( 'control', 'label' ), true) || ! is_array($variant['condition'] ?? null) || ! self::validCondition($variant['condition']) || ! is_array($variant['style_patch'] ?? null) || array() === $variant['style_patch'] || ! is_array($variant['precedence'] ?? null) || ! is_array($variant['provenance'] ?? null) ) {
+            $isVisualPart = 'visual_part' === ($variant['role'] ?? null); $isVisualGroup = 'visual_group' === ($variant['role'] ?? null);
+            $keys = $isVisualPart ? array( 'index', 'role', 'part_id', 'condition', 'style_patch', 'precedence', 'provenance' ) : ($isVisualGroup ? array( 'role', 'group_id', 'condition', 'style_patch', 'precedence', 'provenance' ) : array( 'index', 'role', 'condition', 'style_patch', 'precedence', 'provenance' ));
+            if ( ! is_array($variant) || array_diff(array_keys($variant), $keys) || (! $isVisualGroup && (! is_int($variant['index'] ?? null) || $variant['index'] < 0 || $variant['index'] >= self::MAX_CONTROLS)) || ! in_array($variant['role'] ?? null, $v2 ? array( 'control', 'label', 'required_marker', 'control_container', 'visual_part', 'visual_group' ) : array( 'control', 'label' ), true) || ($isVisualPart ? (! is_string($variant['part_id'] ?? null) || ! isset($partIds[$variant['part_id']]) || $variant['index'] !== $partIds[$variant['part_id']]) : ($isVisualGroup ? (! is_string($variant['group_id'] ?? null) || ! isset($groupIds[$variant['group_id']])) : (isset($variant['part_id']) || isset($variant['group_id'])))) || ! is_array($variant['condition'] ?? null) || ! self::validCondition($variant['condition']) || ! is_array($variant['style_patch'] ?? null) || array() === $variant['style_patch'] || ! is_array($variant['precedence'] ?? null) || ! is_array($variant['provenance'] ?? null) ) {
                 throw new InvalidArgumentException('Form presentation variant is invalid.');
             }
             self::assertStyles($variant['style_patch']);
+            if ( 'control_container' === $variant['role'] ) $containerVariants[$variant['index']] = true;
             foreach ( $variant['precedence'] as $property => $precedence ) {
                 if ( ! in_array($property, self::PROPERTIES, true) || ! isset($variant['style_patch'][self::key($property)]) || ! is_array($precedence) || ! is_int($precedence['source_order'] ?? null) || ! is_int($precedence['specificity'] ?? null) || ! is_bool($precedence['important'] ?? null) ) throw new InvalidArgumentException('Form presentation precedence is invalid.');
             }
             self::assertProvenance($variant['provenance'], $variant['style_patch'], $variant['condition']);
         }
+        foreach ( $containerIndexes as $index => $hasBaseStyles ) if (! $hasBaseStyles && ! isset($containerVariants[$index])) throw new InvalidArgumentException('Form presentation conditional control container has no variants.');
     }
 
-    private static function assertRole(mixed $role, ?array $condition): void
+    private static function assertRole(mixed $role, ?array $condition, bool $allowEmpty = false): void
     {
-        if ( ! is_array($role) || count($role) !== 2 || array_diff(array_keys($role), array( 'styles', 'provenance' )) || ! is_array($role['styles'] ?? null) || array() === $role['styles'] || ! is_array($role['provenance'] ?? null) ) throw new InvalidArgumentException('Form presentation role is invalid.');
+        if ( ! is_array($role) || count($role) !== 2 || array_diff(array_keys($role), array( 'styles', 'provenance' )) || ! is_array($role['styles'] ?? null) || (! $allowEmpty && array() === $role['styles']) || ! is_array($role['provenance'] ?? null) ) throw new InvalidArgumentException('Form presentation role is invalid.');
         self::assertStyles($role['styles']);
         self::assertProvenance($role['provenance'], $role['styles'], $condition);
     }
 
+    /** @param list<DOMElement> $ancestors @return array{container:array<string,mixed>,variants:list<array<string,mixed>}|null */
+    private function controlContainer(int $index, array $ancestors, array $rules, array $customPropertyRules): ?array
+    {
+        $painted = array();
+        $properties = array_flip(self::CONTROL_CONTAINER_PROPERTIES);
+        foreach ( $ancestors as $ancestor ) {
+            $matched = $this->matched($ancestor, $rules);
+            $facts = array_intersect_key($matched['base'], $properties);
+            $styles = $this->styles($facts, $ancestor, null, $customPropertyRules);
+            $variants = array();
+            foreach ( $this->effectiveConditional($matched['conditional'], $matched['base']) as $encoded => $conditionalFacts ) {
+                $condition = json_decode($encoded, true); $conditionalFacts = array_intersect_key($conditionalFacts, $properties);
+                $patch = $this->styles($conditionalFacts, $ancestor, $condition, $customPropertyRules);
+                if ($this->hasContainerPaint($patch)) $variants[] = array( 'index' => $index, 'role' => 'control_container', 'condition' => $condition, 'style_patch' => $patch, 'precedence' => $this->precedence($conditionalFacts), 'provenance' => $this->provenance($conditionalFacts, $condition) );
+            }
+            if ($this->hasContainerPaint($styles) || array() !== $variants) $painted[] = array( 'element' => $ancestor, 'facts' => $this->hasContainerPaint($styles) ? $facts : array(), 'matched' => $matched, 'styles' => $this->hasContainerPaint($styles) ? $styles : array(), 'variants' => $variants );
+        }
+        if ( count($painted) > 1 ) { $this->diagnostics[] = 'control_container_multiple_painted_wrappers'; return null; }
+        if ( array() === $painted ) return null;
+        $paint = $painted[0];
+        $container = array( 'index' => $index, 'source_selector' => SourceDom::elementSelector($paint['element']), 'styles' => $paint['styles'], 'provenance' => $this->provenance($paint['facts'], null) );
+        return array( 'container' => $container, 'variants' => $paint['variants'] );
+    }
+
+    /** A container paint requires a visible fill or border, not radius or neutral resets alone. */
+    private function hasContainerPaint(array $styles): bool
+    {
+        $classifier = new SourceElementClassifier();
+        foreach ( array('background', 'background_color') as $property ) if (isset($styles[$property]) && $classifier->isVisibleEmptyVisualPaint($styles[$property])) return true;
+        if (isset($styles['border']) && $classifier->isVisibleEmptyVisualBorder($styles['border'])) return true;
+        foreach ( array('border_width', 'border_top_width', 'border_right_width', 'border_bottom_width', 'border_left_width') as $property ) if (isset($styles[$property]) && ! $classifier->isPositiveCssLength($styles[$property])) return false;
+        foreach ( array('border_color', 'border_top_color', 'border_right_color', 'border_bottom_color', 'border_left_color') as $property ) if (isset($styles[$property]) && $classifier->isVisibleEmptyVisualPaint($styles[$property])) return true;
+        return false;
+    }
+
+    /** A visual part describes source identity and facts, never an inferred semantic role. */
+    private static function assertVisualPart(mixed $part): void
+    {
+        if ( ! is_array($part) || array_diff(array_keys($part), array( 'id', 'index', 'kind', 'source_selector', 'markup', 'intrinsic_size', 'source_css' )) || ! is_string($part['id'] ?? null) || ! preg_match('/^control-[0-9]+-svg-[0-9]+$/', $part['id']) || ! is_int($part['index'] ?? null) || $part['index'] < 0 || $part['index'] >= self::MAX_CONTROLS || ! is_string($part['source_selector'] ?? null) || '' === trim($part['source_selector']) || strlen($part['source_selector']) > 2048 || 'inline_svg' !== ($part['kind'] ?? null) || ! is_string($part['markup'] ?? null) || strlen($part['markup']) > self::MAX_VISUAL_BYTES || ! SourceDom::isSafeInlineSvgMarkup($part['markup']) || ! is_array($part['source_css'] ?? null) || ! in_array($part['source_css']['state'] ?? null, array( 'known', 'unknown' ), true) ) throw new InvalidArgumentException('Form presentation visual part is invalid.');
+        if ( isset($part['intrinsic_size']) && (! is_array($part['intrinsic_size']) || array_diff(array_keys($part['intrinsic_size']), array( 'width', 'height' )) || ! self::validDimension($part['intrinsic_size']['width'] ?? null) || ! self::validDimension($part['intrinsic_size']['height'] ?? null)) ) throw new InvalidArgumentException('Form presentation visual part dimensions are invalid.');
+        $sourceCss = $part['source_css'];
+        if ( 'known' === $sourceCss['state'] ) {
+            if ( array_diff(array_keys($sourceCss), array( 'state', 'styles', 'provenance' )) || ! is_array($sourceCss['styles'] ?? null) || array() === $sourceCss['styles'] || ! is_array($sourceCss['provenance'] ?? null) ) throw new InvalidArgumentException('Form presentation visual part source CSS is invalid.');
+            self::assertStyles($sourceCss['styles']); self::assertProvenance($sourceCss['provenance'], $sourceCss['styles'], null);
+        } elseif ( array_diff(array_keys($sourceCss), array( 'state' )) ) throw new InvalidArgumentException('Form presentation visual part unknown CSS state is invalid.');
+    }
+
+    /** A visual group retains the authored common container without assigning semantic meaning. */
+    private static function assertVisualGroup(mixed $group, array $partIds): void
+    {
+        if ( ! is_array($group) || array_diff(array_keys($group), array( 'id', 'source_selector', 'part_ids', 'source_css' )) || ! is_string($group['id'] ?? null) || ! preg_match('/^visual-group-[a-f0-9]{16}$/', $group['id']) || ! is_string($group['source_selector'] ?? null) || '' === trim($group['source_selector']) || strlen($group['source_selector']) > 2048 || ! is_array($group['part_ids'] ?? null) || ! array_is_list($group['part_ids']) || count($group['part_ids']) < 2 || count($group['part_ids']) > self::MAX_VISUAL_PARTS || count(array_unique($group['part_ids'])) !== count($group['part_ids']) || array_filter($group['part_ids'], static fn (mixed $id): bool => ! is_string($id) || ! isset($partIds[$id])) || ! is_array($group['source_css'] ?? null) || ! in_array($group['source_css']['state'] ?? null, array( 'known', 'unknown' ), true) ) throw new InvalidArgumentException('Form presentation visual group is invalid.');
+        if ( 'known' === $group['source_css']['state'] ) {
+            if ( array_diff(array_keys($group['source_css']), array( 'state', 'styles', 'provenance' )) || ! is_array($group['source_css']['styles'] ?? null) || array() === $group['source_css']['styles'] || ! is_array($group['source_css']['provenance'] ?? null) ) throw new InvalidArgumentException('Form presentation visual group source CSS is invalid.');
+            self::assertStyles($group['source_css']['styles']); self::assertProvenance($group['source_css']['provenance'], $group['source_css']['styles'], null);
+        } elseif ( array_diff(array_keys($group['source_css']), array( 'state' )) ) throw new InvalidArgumentException('Form presentation visual group unknown CSS state is invalid.');
+    }
+
     private static function assertStyles(array $styles): void
     {
         foreach ( $styles as $key => $value ) if ( ! is_string($key) || ! in_array($key, array_map(self::key(...), self::PROPERTIES), true) || ! is_string($value) || '' === trim($value) || strlen($value) > 160 ) throw new InvalidArgumentException('Form presentation style is invalid.');
@@ -183,6 +334,18 @@ private function controls(DOMElement $form): array
         return $result;
     }
 
+    /** @return list<DOMElement> */
+    private function presentationElements(DOMElement $form): array
+    {
+        $elements = $this->controls($form);
+        foreach ( $this->controls($form) as $control ) {
+            $label = $this->label($control);
+            if ( $label instanceof DOMElement ) $elements[] = $label;
+            if ( null !== $this->requiredMarker && ($marker = ($this->requiredMarker)($control)) instanceof DOMElement ) $elements[] = $marker;
+        }
+        return $elements;
+    }
+
     private function label(DOMElement $control): ?DOMElement
     {
         $id = $control->getAttribute('id');
@@ -191,6 +354,61 @@ private function label(DOMElement $control): ?DOMElement
         return null;
     }
 
+    /** @return list<array{part: array<string,mixed>, variants: list<array<string,mixed>>, group?: array<string,mixed>, group_variants?: list<array<string,mixed>>}> */
+    private function visualParts(DOMElement $control, int $index, array $rules, array $customPropertyRules): array
+    {
+        if ( null === $this->sanitizeInlineSvgMarkup ) return array();
+        $parts = array();
+        $ordinal = 0;
+        foreach ( $control->getElementsByTagName('svg') as $svg ) {
+            if ( ! $svg instanceof DOMElement || ! SourceDom::svgHasDrawableContent($svg) ) continue;
+            if ( count($parts) >= self::MAX_VISUAL_PARTS ) { $this->truncated = true; $this->diagnostics[] = 'visual_part_limit'; break; }
+            $selector = SourceDom::elementSelector($svg);
+            if ( strlen($selector) > 2048 ) { $this->diagnostics[] = 'visual_selector_limit'; continue; }
+            $markup = trim(($this->sanitizeInlineSvgMarkup)($svg));
+            if ( strlen($markup) > self::MAX_VISUAL_BYTES || ! SourceDom::isSafeInlineSvgMarkup($markup) ) { $this->diagnostics[] = 'unsafe_visual_part'; continue; }
+            $matched = $this->matched($svg, $rules);
+            $styles = $this->styles($matched['base'], $svg, null, $customPropertyRules);
+            $part = array( 'id' => 'control-' . $index . '-svg-' . $ordinal++, 'index' => $index, 'kind' => 'inline_svg', 'source_selector' => $selector, 'markup' => $markup, 'source_css' => array( 'state' => 'unknown' ) );
+            $size = $this->intrinsicSize($svg);
+            if ( array() !== $size ) $part['intrinsic_size'] = $size;
+            if ( array() !== $styles ) $part['source_css'] = array( 'state' => 'known', 'styles' => $styles, 'provenance' => $this->provenance($matched['base'], null) );
+            $variants = array();
+            foreach ( $this->effectiveConditional($matched['conditional'], $matched['base']) as $encoded => $facts ) {
+                $condition = json_decode($encoded, true);
+                $patch = $this->styles($facts, $svg, $condition, $customPropertyRules);
+                if ( array() !== $patch ) $variants[] = array( 'index' => $index, 'role' => 'visual_part', 'part_id' => $part['id'], 'condition' => $condition, 'style_patch' => $patch, 'precedence' => $this->precedence($facts), 'provenance' => $this->provenance($facts, $condition) );
+            }
+            $parts[] = array( 'part' => $part, 'variants' => $variants, 'element' => $svg );
+        }
+        $svgs = array_column($parts, 'element');
+        if ( count($svgs) >= 2 && ($groupElement = $this->lowestCommonAncestor($svgs)) instanceof DOMElement ) {
+            $selector = SourceDom::elementSelector($groupElement);
+            if ( strlen($selector) <= 2048 ) {
+                $matched = $this->matched($groupElement, $rules);
+                $styles = $this->styles($matched['base'], $groupElement, null, $customPropertyRules);
+                $group = array( 'id' => 'visual-group-' . substr(hash('sha256', $selector), 0, 16), 'source_selector' => $selector, 'part_ids' => array_column(array_column($parts, 'part'), 'id'), 'source_css' => array( 'state' => 'unknown' ) );
+                if ( array() !== $styles ) $group['source_css'] = array( 'state' => 'known', 'styles' => $styles, 'provenance' => $this->provenance($matched['base'], null) );
+                $groupVariants = array();
+                foreach ( $this->effectiveConditional($matched['conditional'], $matched['base']) as $encoded => $facts ) { $condition = json_decode($encoded, true); $patch = $this->styles($facts, $groupElement, $condition, $customPropertyRules); if ( array() !== $patch ) $groupVariants[] = array( 'role' => 'visual_group', 'group_id' => $group['id'], 'condition' => $condition, 'style_patch' => $patch, 'precedence' => $this->precedence($facts), 'provenance' => $this->provenance($facts, $condition) ); }
+                $parts[array_key_last($parts)]['group'] = $group;
+                $parts[array_key_last($parts)]['group_variants'] = $groupVariants;
+            }
+        }
+        foreach ( $parts as &$part ) unset($part['element']); unset($part);
+        return $parts;
+    }
+
+    /** @param list<DOMElement> $elements */
+    private function lowestCommonAncestor(array $elements): ?DOMElement
+    {
+        for ( $candidate = $elements[0]->parentNode; $candidate instanceof DOMElement; $candidate = $candidate->parentNode ) {
+            foreach ( $elements as $element ) { for ( $current = $element; $current instanceof DOMElement && ! $current->isSameNode($candidate); $current = $current->parentNode instanceof DOMElement ? $current->parentNode : null ) {} if (! $current instanceof DOMElement) continue 2; }
+            return $candidate;
+        }
+        return null;
+    }
+
     /** @param list<array<string, mixed>> $rules */
     private function matched(DOMElement $element, array $rules): array
     {
@@ -227,10 +445,9 @@ private function effectiveConditional(array $conditional, array $base): array
     /** @param list<array<string, mixed>> $rules */
     private function styles(array $facts, DOMElement $element, ?array $condition, array $rules): array
     {
-        $customProperties = $this->cascadedCustomProperties($element, $condition, $rules);
         $result = array();
         foreach ( $facts as $property => $fact ) {
-            $value = $this->expandCustomProperties($fact['value'], $customProperties);
+            $value = FormCustomPropertyResolver::resolve($fact['value'], $element, $condition, $rules);
             if ( null !== $this->resolveValue && str_contains($value, 'var(') ) $value = ($this->resolveValue)($element, $value);
             $result[self::key($property)] = $value;
         }
@@ -238,46 +455,11 @@ private function styles(array $facts, DOMElement $element, ?array $condition, ar
         return $result;
     }
 
-    /**
-     * Resolve source custom properties at the control's cascade scope. Conditional
-     * presentation variants only admit declarations from their own condition, so a
-     * mobile token cannot replace the desktop value in a separate emitted rule.
-     *
-     * @param list<array<string, mixed>> $rules
-     * @return array<string, string>
-     */
-    private function cascadedCustomProperties(DOMElement $element, ?array $condition, array $rules): array
-    {
-        $properties = array();
-        $ancestors = array();
-        for ( $current = $element; $current instanceof DOMElement; $current = $current->parentNode instanceof DOMElement ? $current->parentNode : null ) $ancestors[] = $current;
-        foreach ( array_reverse($ancestors) as $ancestor ) {
-            foreach ( $rules as $rule ) {
-                if ( ( null !== ($rule['condition'] ?? null) && ($rule['condition'] ?? null) !== $condition ) || ! CssSelectorMatcher::matches($ancestor, $rule['parsed_selector'])['matches'] ) continue;
-                foreach ( $rule['declarations'] as $declaration ) {
-                    if ( ! str_starts_with($declaration['name'], '--') ) continue;
-                    $value = preg_replace('/\s*!important\s*$/i', '', $declaration['value']) ?? $declaration['value'];
-                    $fact = array( 'value' => $value, 'order' => $rule['order'], 'specificity' => $rule['specificity'], 'important' => 1 === preg_match('/\s*!important\s*$/i', $declaration['value']) );
-                    CssCascade::apply($properties, $declaration['name'], $fact);
-                }
-            }
-        }
-        return array_map(static fn (array $fact): string => $fact['value'], $properties);
-    }
-
-    /** @param array<string, string> $customProperties */
-    private function expandCustomProperties(string $value, array $customProperties): string
-    {
-        for ( $pass = 0; $pass < 5 && str_contains($value, 'var('); ++$pass ) {
-            $expanded = preg_replace_callback('/var\(\s*(--[A-Za-z0-9_-]+)\s*(?:,\s*([^()]*))?\)/', static function (array $matches) use ($customProperties): string {
-                return $customProperties[$matches[1]] ?? ( isset($matches[2]) ? trim($matches[2]) : $matches[0] );
-            }, $value);
-            if ( ! is_string($expanded) || $expanded === $value ) break;
-            $value = $expanded;
-        }
-        return trim($value);
-    }
     private static function key(string $property): string { return str_replace('-', '_', $property); }
+    /** @return array<string, int> */
+    private function intrinsicSize(DOMElement $svg): array { $width = $this->dimension(SourceDom::attr($svg, 'width')); $height = $this->dimension(SourceDom::attr($svg, 'height')); return null !== $width && null !== $height ? array( 'width' => $width, 'height' => $height ) : array(); }
+    private function dimension(string $value): ?int { return 1 === preg_match('/^[1-9][0-9]{0,3}$/D', trim($value)) && (int) $value <= self::MAX_VISUAL_DIMENSION ? (int) $value : null; }
+    private static function validDimension(mixed $value): bool { return is_int($value) && $value > 0 && $value <= self::MAX_VISUAL_DIMENSION; }
     private function precedence(array $facts): array { $result = array(); foreach ( $facts as $property => $fact ) $result[$property] = array( 'source_order' => $fact['order'], 'specificity' => $fact['specificity'], 'important' => $fact['important'] ); ksort($result); return $result; }
     private function provenance(array $facts, ?array $condition): array { $grouped = array(); foreach ( $facts as $property => $fact ) { $key = $fact['path'] . "\n" . $fact['selector']; $grouped[$key] ??= array( 'source_path' => $fact['path'], 'source_sha256' => $fact['hash'], 'selector' => $fact['selector'], 'condition' => $condition, 'properties' => array() ); $grouped[$key]['properties'][] = $property; } foreach ( $grouped as &$item ) sort($item['properties'], SORT_STRING); unset($item); if ( count($grouped) > self::MAX_PROVENANCE ) { $this->truncated = true; $this->diagnostics[] = 'provenance_limit'; } return array_slice(array_values($grouped), 0, self::MAX_PROVENANCE); }
 
diff --git a/php-transformer/src/HtmlToBlocks/Support/SourceDom.php b/php-transformer/src/HtmlToBlocks/Support/SourceDom.php
index d512b23b9..0f07e2f3e 100644
--- a/php-transformer/src/HtmlToBlocks/Support/SourceDom.php
+++ b/php-transformer/src/HtmlToBlocks/Support/SourceDom.php
@@ -516,6 +516,60 @@ public static function isSafeSvgContent(string $content): bool
         return '' !== trim($content) && preg_match('/<svg(?:\s|>)/i', $content) && ! preg_match('/<\s*script\b|\son[a-z]+\s*=|javascript\s*:/i', $content);
     }
 
+    /**
+     * Validate markup intended for a trusted inline SVG rendering surface.
+     *
+     * This deliberately accepts a small, passive SVG subset instead of trying
+     * to clean caller-controlled markup. XML parsing makes entity decoding and
+     * the single-root requirement part of the boundary rather than regexes.
+     */
+    public static function isSafeInlineSvgMarkup(string $markup): bool
+    {
+        if ( '' === trim($markup) || str_contains($markup, '<?') || preg_match('/<!\s*(?:doctype|entity)\b/i', $markup) || preg_match('/&(?!(?:amp|lt|gt|quot|apos);)/i', $markup) ) {
+            return false;
+        }
+
+        $document = new DOMDocument();
+        $previous = libxml_use_internal_errors(true);
+        $loaded = $document->loadXML($markup, LIBXML_NONET | LIBXML_NOERROR | LIBXML_NOWARNING | LIBXML_COMPACT);
+        libxml_clear_errors();
+        libxml_use_internal_errors($previous);
+        if ( ! $loaded || ! $document->documentElement instanceof DOMElement || 'svg' !== strtolower($document->documentElement->tagName) ) {
+            return false;
+        }
+
+        $allowedTags = array_flip(array(
+            'svg', 'g', 'path', 'circle', 'ellipse', 'rect', 'line', 'polyline', 'polygon',
+            'text', 'tspan', 'title', 'desc', 'defs', 'lineargradient', 'radialgradient',
+            'stop', 'clippath', 'mask', 'pattern', 'marker', 'filter', 'feblend',
+            'fecolormatrix', 'fecomposite', 'fegaussianblur', 'femerge', 'femergenode',
+            'feoffset', 'feflood', 'feturbulence',
+        ));
+        $blockedAttributes = array_flip(array( 'href', 'xlink:href', 'src', 'style' ));
+        $nodes = array( $document->documentElement );
+        while ( array() !== $nodes ) {
+            /** @var DOMElement $element */
+            $element = array_pop($nodes);
+            if ( ! isset($allowedTags[strtolower($element->tagName)]) ) {
+                return false;
+            }
+            foreach ( $element->attributes as $attribute ) {
+                $name = strtolower($attribute->name);
+                $value = trim($attribute->value);
+                if ( str_starts_with($name, 'on') || isset($blockedAttributes[$name]) || (str_contains($name, ':') && ! in_array($name, array( 'xmlns', 'xml:lang', 'xml:space' ), true)) || preg_match('/(?:^|[^a-z])url\s*\(/i', $value) ) {
+                    return false;
+                }
+            }
+            foreach ( $element->childNodes as $child ) {
+                if ( $child instanceof DOMElement ) {
+                    $nodes[] = $child;
+                }
+            }
+        }
+
+        return true;
+    }
+
     /**
      * Whether an inline SVG carries any drawable artwork worth preserving.
      *
diff --git a/php-transformer/tests/contract/run.php b/php-transformer/tests/contract/run.php
index 1617e4757..5a9da17a6 100644
--- a/php-transformer/tests/contract/run.php
+++ b/php-transformer/tests/contract/run.php
@@ -1298,11 +1298,39 @@ public function recognize(DOMElement $element, PatternContext $context): ?Patter
 $projectedDeepGraph = $deepDeclaration['payload']['entities'][0]['layout_graph'] ?? array();
 $projectedWidthNodes = array_values(array_filter($projectedDeepGraph['nodes'] ?? array(), static fn(array $node): bool => 'td' === ($node['source']['tag'] ?? null) && '33.333333333333%' === ($node['layout']['width'] ?? null)));
 $assert(3 === count($projectedWidthNodes) && false === ($projectedDeepGraph['truncated'] ?? null), 'artifact compilation projects the complete deep percentage-width graph into generic/forms/v1.');
+$conditionalLayoutTokenArtifact = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'files' => array('index.html' => '<link rel="stylesheet" href="style.css"><form class="form"><div class="scope"><div class="field"><input name="email"></div></div></form>', 'style.css' => '.form{--base-spacing:24;--spacing:var(--base-spacing);--field-gap:calc(var(--spacing)*1px)}.scope{--spacing:28}.field{display:flex;flex-direction:column;gap:var(--field-gap,24px)}@media (max-width:50rem){.scope{--field-gap:32px}}')))->toArray();
+$conditionalLayoutTokenDeclaration = current(array_filter($conditionalLayoutTokenArtifact['source_reports']['wordpress_site_plan']['runtime_declarations'] ?? array(), static fn(array $declaration): bool => 'forms' === ($declaration['type'] ?? null)));
+$conditionalLayoutTokenFallback = current(array_filter($conditionalLayoutTokenArtifact['fallbacks'] ?? array(), static fn(array $fallback): bool => 'html_form_fallback' === ($fallback['diagnostic_code'] ?? null)));
+$conditionalLayoutTokenGraph = $conditionalLayoutTokenFallback['layout_graph'] ?? array();
+$conditionalLayoutTokenNodes = array_column($conditionalLayoutTokenGraph['nodes'] ?? array(), null, 'id');
+$assert('calc(24*1px)' === ($conditionalLayoutTokenNodes['wrapper-1']['layout']['gap'] ?? null) && true === ($conditionalLayoutTokenGraph['truncated'] ?? null) && in_array('conditional_custom_property_layout', $conditionalLayoutTokenGraph['diagnostics'] ?? array(), true) && !isset($conditionalLayoutTokenDeclaration['payload']['entities'][0]['layout_graph']), 'form layout computes inherited chained custom properties at their declaring ancestor and fails closed when a responsive token alone would change an emitted layout fact.');
+$cyclicLayoutGraph = (new HtmlTransformer())->transform('<form><div class="field"><input name="email"></div></form>', array('static_css' => '.field{--first:var(--second);--second:var(--first);display:flex;gap:var(--first,19px)}'))->toArray()['fallbacks'][0]['layout_graph'] ?? array();
+$cyclicLayoutNodes = array_column($cyclicLayoutGraph['nodes'] ?? array(), null, 'id');
+$assert('19px' === ($cyclicLayoutNodes['wrapper-0']['layout']['gap'] ?? null), 'form layout resolves cyclic custom properties as unavailable and retains the consuming declaration fallback.');
+$shadowedLayoutGraph = (new HtmlTransformer())->transform('<form><div class="field"><input name="email"></div></form>', array('static_css' => 'form{--field-gap:24px}.field{--field-gap:var(--missing);display:flex;gap:var(--field-gap,19px)}'))->toArray()['fallbacks'][0]['layout_graph'] ?? array();
+$shadowedLayoutNodes = array_column($shadowedLayoutGraph['nodes'] ?? array(), null, 'id');
+$assert('19px' === ($shadowedLayoutNodes['wrapper-0']['layout']['gap'] ?? null), 'an invalid local custom property shadows an inherited token and falls through to the consuming declaration fallback.');
+$capturedPseudoFormDocument = new DOMDocument();
+@$capturedPseudoFormDocument->loadHTML('<div class="data-liberation-desktop-document"><div class="comp"><div class="sN4uTVR"><div class="ckHV4G"><input name="email"></div></div></div></div><div class="data-liberation-mobile-document"><div class="comp"><div class="sN4uTVR"><div class="ckHV4G"><input name="email"></div></div></div></div>');
+$capturedPseudoFormStylesheets = array(
+    array('content' => '.comp{--rowSpacing:32}.sN4uTVR{--wix-forms-formRowSpacing:calc(var(--rowSpacing) * 1px)}.ckHV4G{display:flex;flex-direction:column;gap:var(--wix-forms-formRowSpacing,24px)}', 'source_path' => 'desktop.css', 'source_hash' => hash('sha256', 'desktop'), 'media' => '(min-width:769px)'),
+    array('content' => ':where(.data-liberation-mobile-document) .comp{--rowSpacing:32}:where(.data-liberation-mobile-document) .sN4uTVR{--wix-forms-formRowSpacing:calc(var(--rowSpacing) * 1px)}:where(.data-liberation-mobile-document) .ckHV4G{display:flex;flex-direction:column;gap:var(--wix-forms-formRowSpacing,24px)}', 'source_path' => 'mobile.css', 'source_hash' => hash('sha256', 'mobile'), 'media' => '(max-width:768px)'),
+);
+$capturedDesktopPseudoFormGraph = (new \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormLayoutGraphBuilder())->build($capturedPseudoFormDocument->getElementsByTagName('div')->item(3), $capturedPseudoFormStylesheets);
+$capturedMobilePseudoFormGraph = (new \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormLayoutGraphBuilder())->build($capturedPseudoFormDocument->getElementsByTagName('div')->item(7), $capturedPseudoFormStylesheets);
+$capturedPseudoFormVariant = static fn (array $graph, string $query): array => current(array_filter($graph['variants'] ?? array(), static fn (array $variant): bool => $query === ($variant['condition']['query'] ?? null))) ?: array();
+$capturedDesktopPseudoFormVariant = $capturedPseudoFormVariant($capturedDesktopPseudoFormGraph, '(min-width:769px)');
+$capturedMobilePseudoFormVariant = $capturedPseudoFormVariant($capturedMobilePseudoFormGraph, '(max-width:768px)');
+$assert(false === ($capturedDesktopPseudoFormGraph['truncated'] ?? null) && false === ($capturedMobilePseudoFormGraph['truncated'] ?? null) && 'div' === ($capturedDesktopPseudoFormGraph['nodes'][0]['source']['tag'] ?? null) && 'flex' === ($capturedDesktopPseudoFormVariant['layout_patch']['display'] ?? null) && 'calc(32 * 1px)' === ($capturedDesktopPseudoFormVariant['layout_patch']['gap'] ?? null) && 'calc(32 * 1px)' === ($capturedMobilePseudoFormVariant['layout_patch']['gap'] ?? null) && '(min-width:769px)' === ($capturedDesktopPseudoFormVariant['condition']['query'] ?? null) && '(max-width:768px)' === ($capturedMobilePseudoFormVariant['condition']['query'] ?? null), 'layout graph retains pseudo-form roots and resolves paired desktop/mobile scoped row-spacing tokens.');
 $safeProvenanceArtifact = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'files' => array('index.html' => '<link rel="stylesheet" href="assets/form style.css">' . $layoutGraphHtml, 'assets/form style.css' => '.form{display:grid}')))->toArray();
 $safeProvenanceDeclaration = current(array_filter($safeProvenanceArtifact['source_reports']['wordpress_site_plan']['runtime_declarations'] ?? array(), static fn(array $declaration): bool => 'forms' === ($declaration['type'] ?? null)));
 $safeProvenanceGraph = $safeProvenanceDeclaration['payload']['entities'][0]['layout_graph'] ?? array();
 $safeProvenanceNode = array_column($safeProvenanceGraph['nodes'] ?? array(), null, 'id')['form'] ?? array();
 $assert('assets/form style.css' === ($safeProvenanceNode['provenance'][0]['source_path'] ?? null), 'artifact compilation accepts canonical stylesheet paths in emitted form layout provenance.');
+$boundedInlineStylesArtifact = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'limits' => array('max_files' => 2), 'files' => array('index.html' => '<style>.form{display:grid;gap:var(--row-gap,24px)}</style><form class="form" style="--row-gap:32px"><input name="email"></form>', 'unrelated.txt' => 'accepted source file')))->toArray();
+$boundedInlineStylesDeclaration = current(array_filter($boundedInlineStylesArtifact['source_reports']['wordpress_site_plan']['runtime_declarations'] ?? array(), static fn(array $declaration): bool => 'forms' === ($declaration['type'] ?? null)));
+$boundedInlineStylesNode = array_column($boundedInlineStylesDeclaration['payload']['entities'][0]['layout_graph']['nodes'] ?? array(), null, 'id')['form'] ?? array();
+$assert('grid' === ($boundedInlineStylesNode['layout']['display'] ?? null) && '32px' === ($boundedInlineStylesNode['layout']['gap'] ?? null), 'artifact compilation retains inline form stylesheet facts when generated stylesheet files are omitted at the bounded artifact file limit.');
 $depthBoundaryHtml = '<form>' . str_repeat('<div>', 16) . '<input name="edge">' . str_repeat('</div>', 16) . '<button type="submit">Send</button></form>';
 $depthOverflowHtml = '<form>' . str_repeat('<div>', 17) . '<input name="overflow">' . str_repeat('</div>', 17) . '<button type="submit">Send</button></form>';
 $depthBoundaryGraph = (new HtmlTransformer())->transform($depthBoundaryHtml, array('static_css' => 'input{width:100%}'))->toArray()['fallbacks'][0]['layout_graph'] ?? array();
@@ -1331,6 +1359,13 @@ public function recognize(DOMElement $element, PatternContext $context): ?Patter
 $ancestryIds = array_flip(array_column($ancestryGraph['nodes'] ?? array(), 'id')); foreach ($ancestryGraph['nodes'] ?? array() as $node) $assert(null === ($node['parent'] ?? null) || isset($ancestryIds[$node['parent']]), 'layout graph emits deterministic ancestry instead of dangling parents.');
 $boundedCss = str_repeat('.form{display:grid}', 600); $boundedGraph = (new HtmlTransformer())->transform($layoutGraphHtml, array('static_css' => $boundedCss))->toArray()['fallbacks'][0]['layout_graph'] ?? array();
 $assert(true === ($boundedGraph['truncated'] ?? null) && in_array('css_rule_or_selector_limit', $boundedGraph['diagnostics'] ?? array(), true), 'layout graph bounds CSS parsing and rule matching work with explicit diagnostics.');
+$largeValidCss = '/*' . str_repeat('x', 262145) . '*/.form{display:flex}.form{display:grid;grid-template-columns:1fr 1fr}';
+$largeValidGraph = (new HtmlTransformer())->transform($layoutGraphHtml, array('static_css' => $largeValidCss))->toArray()['fallbacks'][0]['layout_graph'] ?? array();
+$largeValidForm = array_column($largeValidGraph['nodes'] ?? array(), null, 'id')['form'] ?? array();
+$assert(false === ($largeValidGraph['truncated'] ?? null) && 'grid' === ($largeValidForm['layout']['display'] ?? null) && '1fr 1fr' === ($largeValidForm['layout']['columns'] ?? null) && '.form' === ($largeValidForm['provenance'][0]['selector'] ?? null) && !in_array('css_bytes_truncated:inline-style', $largeValidGraph['diagnostics'] ?? array(), true), 'layout graph retains a late authored grid winner and its provenance after valid CSS exceeds the former 256 KiB budget.');
+$oversizedCss = '/*' . str_repeat('x', 4194305) . '*/.form{display:grid}';
+$oversizedGraph = (new HtmlTransformer())->transform($layoutGraphHtml, array('static_css' => $oversizedCss))->toArray()['fallbacks'][0]['layout_graph'] ?? array();
+$assert(true === ($oversizedGraph['truncated'] ?? null) && in_array('css_bytes_truncated:inline-style', $oversizedGraph['diagnostics'] ?? array(), true) && !isset(array_column($oversizedGraph['nodes'] ?? array(), null, 'id')['form']['layout']['display']), 'layout graph remains bounded and fails closed when a stylesheet exceeds the shared 4 MiB source-analysis limit.');
 $invalidLayoutGraph = $layoutGraph; $invalidLayoutGraph['nodes'][0]['id'] = 'wrapper-0'; try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormLayoutGraphBuilder::assertValid($invalidLayoutGraph); $assert(false, 'layout graph validation rejects duplicate node identities'); } catch (\InvalidArgumentException) { $assert(true, 'layout graph validation rejects duplicate node identities'); }
 $unsafeGraph = $layoutGraph; $unsafeGraph['nodes'][0]['provenance'][0]['source_path'] = '../../untrusted.css'; try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormLayoutGraphBuilder::assertValid($unsafeGraph); $assert(false, 'layout graph validation rejects unsafe provenance traversal paths'); } catch (\InvalidArgumentException) { $assert(true, 'layout graph validation rejects unsafe provenance traversal paths'); }
 $semanticGraph = $layoutGraph; $semanticGraph['nodes'][0]['layout']['unknown_layout'] = 'value'; try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormLayoutGraphBuilder::assertValid($semanticGraph); $assert(false, 'layout graph validation rejects unknown semantic layout keys'); } catch (\InvalidArgumentException) { $assert(true, 'layout graph validation rejects unknown semantic layout keys'); }
@@ -1346,7 +1381,7 @@ public function recognize(DOMElement $element, PatternContext $context): ?Patter
 $presentationGraph = $presentationFallback['presentation_graph'] ?? array();
 $presentationRows = array_column($presentationGraph['controls'] ?? array(), null, 'index');
 $presentationVariant = $presentationGraph['variants'][0] ?? array();
-$assert('generic/computed-form-presentation/v1' === ($presentationGraph['schema'] ?? null) && '40px' === ($presentationRows[0]['control']['styles']['height'] ?? null) && 'transparent' === ($presentationRows[0]['control']['styles']['background'] ?? null) && '14px' === ($presentationRows[0]['label']['styles']['font_size'] ?? null) && '8px' === ($presentationRows[0]['label']['styles']['margin_bottom'] ?? null) && 'input' === ($presentationRows[0]['control']['provenance'][0]['selector'] ?? null), 'form presentation graph captures source control and associated-label declarations with stylesheet provenance');
+$assert('generic/computed-form-presentation/v1' === ($presentationGraph['schema'] ?? null) && !isset($presentationGraph['visual_parts']) && '40px' === ($presentationRows[0]['control']['styles']['height'] ?? null) && 'transparent' === ($presentationRows[0]['control']['styles']['background'] ?? null) && '14px' === ($presentationRows[0]['label']['styles']['font_size'] ?? null) && '8px' === ($presentationRows[0]['label']['styles']['margin_bottom'] ?? null) && 'input' === ($presentationRows[0]['control']['provenance'][0]['selector'] ?? null), 'form presentation graphs without visual parts retain the persisted v1 envelope and source control facts');
 $assert('10px' === ($presentationRows[0]['control']['styles']['border_radius'] ?? null) && '3px 3px 3px 10px' === ($presentationRows[0]['control']['styles']['padding'] ?? null) && !str_contains(json_encode($presentationGraph), 'var('), 'form presentation graph resolves source-scoped custom properties before provider projection');
 $scopedPresentationCss = '#field{--control-radius:12px;--control-padding:4px 5px 6px 7px}input{border-radius:var(--control-radius,0);padding:var(--control-padding)}';
 $scopedPresentationGraph = (new HtmlTransformer())->transform('<form><div id="field"><input name="phone"></div></form>', array('static_css' => $scopedPresentationCss))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
@@ -1359,8 +1394,39 @@ public function recognize(DOMElement $element, PatternContext $context): ?Patter
 $assert('85px' === ($responsiveTokenVariants['(max-width:50rem)']['style_patch']['height'] ?? null) && '8px' === ($responsiveTokenVariants['(max-width:50rem)']['style_patch']['padding_inline_start'] ?? null) && '86px' === ($responsiveTokenVariants['(min-width:51rem)']['style_patch']['height'] ?? null) && '10px' === ($responsiveTokenVariants['(min-width:51rem)']['style_patch']['padding_inline_start'] ?? null) && !str_contains(json_encode($responsiveTokenGraph), 'var('), 'form presentation resolves ancestor custom properties within each responsive condition before provider projection');
 $caseSensitiveTokenGraph = (new HtmlTransformer())->transform('<form><div id="field"><textarea name="message"></textarea></div></form>', array('static_css' => '#field{--inputHeight:86px}textarea{height:var(--inputHeight)}'))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
 $assert('86px' === ($caseSensitiveTokenGraph['controls'][0]['control']['styles']['height'] ?? null), 'form presentation preserves case-sensitive custom property names while resolving source controls');
+$requiredMarkerCss = '.contact-label{--marker-size:14px;font-size:14px;line-height:19.6px}.contact-label .marker{font-size:var(--marker-size);line-height:19.6px}@media (max-width:50rem){.contact-label .marker{font-size:12px;margin-left:2px}}';
+$requiredMarkerGraph = (new HtmlTransformer())->transform('<form><label class="contact-label" for="email">Email <span class="marker" aria-hidden="true">*</span></label><input id="email" name="email" required></form>', array('static_css' => $requiredMarkerCss))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$requiredMarkerRow = $requiredMarkerGraph['controls'][0]['required_marker'] ?? array();
+$requiredMarkerVariant = current(array_filter($requiredMarkerGraph['variants'] ?? array(), static fn(array $variant): bool => 'required_marker' === ($variant['role'] ?? null)));
+$assert('generic/computed-form-presentation/v2' === ($requiredMarkerGraph['schema'] ?? null) && '14px' === ($requiredMarkerRow['styles']['font_size'] ?? null) && '19.6px' === ($requiredMarkerRow['styles']['line_height'] ?? null) && '.contact-label .marker' === ($requiredMarkerRow['provenance'][0]['selector'] ?? null) && '12px' === ($requiredMarkerVariant['style_patch']['font_size'] ?? null) && '2px' === ($requiredMarkerVariant['style_patch']['margin_left'] ?? null), 'form presentation reuses the explicit required-marker identity, its ancestor custom property scope, and conditional source CSS facts');
+$inheritedRequiredMarkerGraph = (new HtmlTransformer())->transform('<form><label class="contact-label" for="name">Name <span aria-hidden="true">*</span></label><input id="name" name="name" required></form>', array('static_css' => '.contact-label{font-size:14px;line-height:19.6px}'))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$assert('generic/computed-form-presentation/v2' === ($inheritedRequiredMarkerGraph['schema'] ?? null) && array() === ($inheritedRequiredMarkerGraph['controls'][0]['required_marker']['styles'] ?? null) && array() === ($inheritedRequiredMarkerGraph['controls'][0]['required_marker']['provenance'] ?? null), 'form presentation safely retains an explicit inherited required marker without inventing CSS provenance');
+$containerPresentationGraph = (new HtmlTransformer())->transform('<form><label for="email">Email</label><div class="field"><input id="email" name="email"></div><div class="shared"><input name="first"><input name="last"></div><div class="plain"><input name="plain"></div></form>', array('static_css' => 'input{border:0}.field{border:1px solid rgba(30,75,110,.6);background:rgb(247,249,251);border-radius:0}.shared{border:2px solid #111}.plain{display:block}'))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$containerRows = array_column($containerPresentationGraph['control_containers'] ?? array(), null, 'index');
+$assert('generic/computed-form-presentation/v2' === ($containerPresentationGraph['schema'] ?? null) && '1px solid rgba(30,75,110,.6)' === ($containerRows[0]['styles']['border'] ?? null) && 'rgb(247,249,251)' === ($containerRows[0]['styles']['background'] ?? null) && '0' === ($containerRows[0]['styles']['border_radius'] ?? null) && '.field' === ($containerRows[0]['provenance'][0]['selector'] ?? null) && !isset($containerRows[1]) && !isset($containerRows[2]) && !isset($containerRows[3]), 'form presentation retains only an exclusively owned painted control container, preserving its source CSS provenance without assigning shared or borderless wrappers');
+$nestedContainerGraph = (new HtmlTransformer())->transform('<form><div class="outer"><div class="inner"><input name="email"></div></div></form>', array('static_css' => '.outer{border:1px solid #111}.inner{background:#fff}'))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$assert(array() === ($nestedContainerGraph['control_containers'] ?? array()) && in_array('control_container_multiple_painted_wrappers', $nestedContainerGraph['diagnostics'] ?? array(), true), 'form presentation reports nested painted control containers rather than collapsing multiple source chrome layers onto one provider target');
+$conditionalContainerGraph = (new HtmlTransformer())->transform('<form><div><div class="field"><input name="email"></div></div></form>', array('static_css' => 'div{border:0;background:0 0}@media (max-width:48rem){.field{border:1px solid #123;background:#fff}}'))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$conditionalContainer = $conditionalContainerGraph['control_containers'][0] ?? array(); $conditionalContainerVariant = current(array_filter($conditionalContainerGraph['variants'] ?? array(), static fn(array $variant): bool => 'control_container' === ($variant['role'] ?? null)));
+$assert(array() === ($conditionalContainer['styles'] ?? null) && str_ends_with((string) ($conditionalContainer['source_selector'] ?? ''), 'div:nth-of-type(1)') && '1px solid #123' === ($conditionalContainerVariant['style_patch']['border'] ?? null) && '#fff' === ($conditionalContainerVariant['style_patch']['background'] ?? null) && 'media' === ($conditionalContainerVariant['condition']['kind'] ?? null), 'form presentation preserves an exclusively owned condition-only painted container without treating neutral base resets as paint');
+$invalidConditionalContainerGraph = $conditionalContainerGraph; $invalidConditionalContainerGraph['variants'] = array(); try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormPresentationGraphBuilder::assertValid($invalidConditionalContainerGraph); $assert(false, 'form presentation validation rejects an empty-base control container without same-index variants'); } catch (\InvalidArgumentException) { $assert(true, 'form presentation validation rejects an empty-base control container without same-index variants'); }
+$visualPresentationHtml = '<form><button type="button" aria-label="Country"><span class="visual-group"><svg class="globe" width="24" height="24" viewBox="0 0 24 24" onclick="unsafe()"><path d="M3 3h18v18H3z"/></svg><svg class="chevron" width="20" height="20" viewBox="0 0 20 20"><path d="M4 7l6 6 6-6"/></svg></span></button><input type="tel" name="phone"></form>';
+$visualPresentationCss = '.visual-group{display:flex;flex-direction:row;align-items:center;justify-content:space-between;gap:8px;position:relative}.globe{width:24px;height:24px;flex:none}.chevron{width:16px;height:16px;position:absolute;right:8px}@media (max-width:50rem){.visual-group{gap:4px}.chevron{width:12px;right:4px}}';
+$visualPresentationGraph = (new HtmlTransformer())->transform($visualPresentationHtml, array('static_css' => $visualPresentationCss))->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$visualParts = $visualPresentationGraph['visual_parts'] ?? array();
+$visualGroups = $visualPresentationGraph['visual_groups'] ?? array();
+$visualVariants = array(); foreach ($visualPresentationGraph['variants'] ?? array() as $variant) if ('visual_part' === ($variant['role'] ?? null)) $visualVariants[$variant['part_id'] ?? ''] = $variant;
+$visualGroupVariant = current(array_filter($visualPresentationGraph['variants'] ?? array(), static fn(array $variant): bool => 'visual_group' === ($variant['role'] ?? null)));
+$assert(2 === count($visualParts) && 'control-0-svg-0' === ($visualParts[0]['id'] ?? null) && 'inline_svg' === ($visualParts[0]['kind'] ?? null) && 24 === ($visualParts[0]['intrinsic_size']['width'] ?? null) && '24px' === ($visualParts[0]['source_css']['styles']['width'] ?? null) && '24px' === ($visualParts[0]['source_css']['styles']['height'] ?? null) && '.globe' === ($visualParts[0]['source_css']['provenance'][0]['selector'] ?? null) && !str_contains((string) ($visualParts[0]['markup'] ?? ''), 'onclick') && 'control-0-svg-1' === ($visualParts[1]['id'] ?? null) && 20 === ($visualParts[1]['intrinsic_size']['width'] ?? null) && '16px' === ($visualParts[1]['source_css']['styles']['width'] ?? null) && 'absolute' === ($visualParts[1]['source_css']['styles']['position'] ?? null) && '8px' === ($visualParts[1]['source_css']['styles']['right'] ?? null) && '12px' === ($visualVariants['control-0-svg-1']['style_patch']['width'] ?? null) && 'media' === ($visualVariants['control-0-svg-1']['condition']['kind'] ?? null), 'form presentation identifies visual SVG descendants by control order and source selector, retaining intrinsic geometry, actual CSS layout facts, conditional variants, provenance, and sanitized markup without semantic role guesses');
+$assert(1 === count($visualGroups) && str_ends_with((string) ($visualGroups[0]['source_selector'] ?? ''), 'span:nth-of-type(1)') && array('control-0-svg-0', 'control-0-svg-1') === ($visualGroups[0]['part_ids'] ?? null) && 'flex' === ($visualGroups[0]['source_css']['styles']['display'] ?? null) && 'row' === ($visualGroups[0]['source_css']['styles']['flex_direction'] ?? null) && 'center' === ($visualGroups[0]['source_css']['styles']['align_items'] ?? null) && 'space-between' === ($visualGroups[0]['source_css']['styles']['justify_content'] ?? null) && '8px' === ($visualGroups[0]['source_css']['styles']['gap'] ?? null) && '4px' === ($visualGroupVariant['style_patch']['gap'] ?? null), 'form presentation retains the SVG LCA source identity and only authored visual-group flex facts plus its conditional gap without control-index ownership');
+$conditionalVisualGraph = (new HtmlTransformer())->transform('<style>@media (max-width:768px){.indicator svg{width:max(var(--size,16px),16px)}}</style><form><button type="button"><span class="indicator"><svg viewBox="0 0 20 20"><path d="M0 0h1v1z"/></svg></span></button><input name="phone"></form>')->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$assert('unknown' === ($conditionalVisualGraph['visual_parts'][0]['source_css']['state'] ?? null) && 'visual_part' === ($conditionalVisualGraph['variants'][0]['role'] ?? null) && 'max(16px,16px)' === ($conditionalVisualGraph['variants'][0]['style_patch']['width'] ?? null), 'conditional-only visual sizing remains in its responsive variant even when base CSS is unknown');
+$unknownVisualGraph = (new HtmlTransformer())->transform('<form><button type="button"><svg viewBox="0 0 1 1"><path d="M0 0h1v1z"/></svg></button><input type="tel" name="phone"></form>')->toArray()['fallbacks'][0]['presentation_graph'] ?? array();
+$assert('unknown' === ($unknownVisualGraph['visual_parts'][0]['source_css']['state'] ?? null), 'form presentation explicitly represents unknown source CSS instead of inventing visual semantics');
 $invalidPresentation = $presentationGraph; $invalidPresentation['controls'][0]['control']['styles']['untrusted'] = 'value'; try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormPresentationGraphBuilder::assertValid($invalidPresentation); $assert(false, 'presentation graph validation rejects unknown style properties'); } catch (\InvalidArgumentException) { $assert(true, 'presentation graph validation rejects unknown style properties'); }
 $unsafePresentation = $presentationGraph; $unsafePresentation['controls'][0]['control']['provenance'][0]['source_path'] = '../untrusted.css'; try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormPresentationGraphBuilder::assertValid($unsafePresentation); $assert(false, 'presentation graph validation rejects unsafe provenance paths'); } catch (\InvalidArgumentException) { $assert(true, 'presentation graph validation rejects unsafe provenance paths'); }
+$unsafeVisualPresentation = $visualPresentationGraph; $unsafeVisualPresentation['visual_parts'][0]['markup'] = '<svg><animate attributeName="href" to="javascript:alert(1)"/></svg>'; try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormPresentationGraphBuilder::assertValid($unsafeVisualPresentation); $assert(false, 'presentation graph validation rejects unsafe visual payloads'); } catch (\InvalidArgumentException) { $assert(true, 'presentation graph validation rejects unsafe visual payloads'); }
+$misownedVisualVariant = $visualPresentationGraph; $misownedVisualVariant['variants'][0]['index'] = 1; try { \Automattic\BlocksEngine\PhpTransformer\HtmlToBlocks\Style\FormPresentationGraphBuilder::assertValid($misownedVisualVariant); $assert(false, 'presentation graph validation rejects visual variants owned by another control'); } catch (\InvalidArgumentException) { $assert(true, 'presentation graph validation rejects visual variants owned by another control'); }
 $provenanceLimitedProperties = array('appearance', 'background', 'border', 'border-radius', 'box-sizing', 'color', 'display', 'font-family', 'font-size', 'font-style', 'font-variant', 'font-weight', 'height', 'letter-spacing', 'line-height', 'margin', 'max-width');
 $provenanceLimitedCss = implode('', array_map(static fn (string $property, int $index): string => 'input.rule-' . $index . '{' . $property . ':initial}', $provenanceLimitedProperties, array_keys($provenanceLimitedProperties)));
 $provenanceLimitedHtml = '<main><form><input class="' . implode(' ', array_map(static fn (int $index): string => 'rule-' . $index, range(0, 16))) . '"></form></main>';
diff --git a/php-transformer/tests/contract/wordpress-site-plan.php b/php-transformer/tests/contract/wordpress-site-plan.php
index db6820aa5..228d74d38 100644
--- a/php-transformer/tests/contract/wordpress-site-plan.php
+++ b/php-transformer/tests/contract/wordpress-site-plan.php
@@ -346,6 +346,14 @@
 $projectedTopology = $topologyDeclaration['payload']['entities'][0]['control_topology'] ?? null;
 $assert(is_array($projectedTopology) && RuntimeDeclarations::hash($projectedTopology) === RuntimeDeclarations::hash($topologyFallback['control_topology'] ?? null), 'Artifact compiler and WordPress site plan project the generic form control topology unchanged.');
 $assert('wrapper-0' === ($projectedTopology['nodes'][1]['parent'] ?? null) && 'wrapper-0' === ($projectedTopology['nodes'][3]['parent'] ?? null) && array(0, 1) === array($projectedTopology['nodes'][1]['order'] ?? null, $projectedTopology['nodes'][3]['order'] ?? null) && array(0, 1, 2) === array($projectedTopology['nodes'][2]['control'] ?? null, $projectedTopology['nodes'][4]['control'] ?? null, $projectedTopology['nodes'][6]['control'] ?? null), 'The generic/forms/v1 declaration retains shared-row identity, source order, and flat control references.');
+$auxiliaryVisualResult = (new ArtifactCompiler())->compile(array('entrypoint' => 'index.html', 'files' => array('index.html' => '<link rel="stylesheet" href="style.css"><main><form><button type="button" aria-label="Select country"><svg class="globe" width="24" height="24" viewBox="0 0 24 24" onclick="unsafe()"><path d="M3 3h18v18H3z"/></svg><svg class="chevron" width="20" height="20" viewBox="0 0 20 20"><path d="M4 7l6 6 6-6"/></svg></button><input type="tel" name="phone"></form></main>', 'style.css' => '.globe{width:24px;height:24px}.chevron{width:16px;height:16px}@media (max-width:50rem){.chevron{width:12px}}')))->toArray();
+$auxiliaryVisualDeclaration = current(array_filter($auxiliaryVisualResult['source_reports']['wordpress_site_plan']['runtime_declarations'] ?? array(), static fn(array $declaration): bool => 'forms' === ($declaration['type'] ?? null)));
+$auxiliaryVisualGraph = $auxiliaryVisualDeclaration['payload']['entities'][0]['presentation_graph'] ?? array();
+$auxiliaryVisuals = $auxiliaryVisualGraph['visual_parts'] ?? array();
+$assert('generic/computed-form-presentation/v2' === ($auxiliaryVisualGraph['schema'] ?? null) && 2 === count($auxiliaryVisuals) && 'control-0-svg-0' === ($auxiliaryVisuals[0]['id'] ?? null) && 'inline_svg' === ($auxiliaryVisuals[0]['kind'] ?? null) && 24 === ($auxiliaryVisuals[0]['intrinsic_size']['width'] ?? null) && '24px' === ($auxiliaryVisuals[0]['source_css']['styles']['width'] ?? null) && !str_contains((string) ($auxiliaryVisuals[0]['markup'] ?? ''), 'onclick') && 20 === ($auxiliaryVisuals[1]['intrinsic_size']['width'] ?? null) && '16px' === ($auxiliaryVisuals[1]['source_css']['styles']['width'] ?? null) && !isset($auxiliaryVisualDeclaration['payload']['entities'][0]['controls'][1]['auxiliary_visuals']), 'WordPress site plans retain identified, sanitized SVG visual parts with intrinsic geometry and actual source CSS facts, rather than flat candidate roles.');
+$unsafeVisualPayload = array('entrypoint' => 'index.html', 'runtime_declarations' => array(array('kind' => 'entity_collection', 'type' => 'forms', 'source_path' => 'index.html', 'payload' => array('schema' => 'generic/forms/v1', 'entities' => array(array('presentation_graph' => $auxiliaryVisualGraph))))), 'files' => array('index.html' => '<main>Caller</main>'));
+$unsafeVisualPayload['runtime_declarations'][0]['payload']['entities'][0]['presentation_graph']['visual_parts'][0]['markup'] = '<svg><animate attributeName="href" to="javascript:alert(1)"/></svg>';
+$throws(static fn() => (new ArtifactCompiler())->compile($unsafeVisualPayload), 'Runtime declaration intake rejects unsafe identified visual-part payloads.');
 $layoutArtifact = array('entrypoint' => 'index.html', 'files' => array('index.html' => '<link rel="stylesheet" href="css/style.css"><main><form class="form" action="/contact"><div class="row-2"><div class="field"><input name="first"></div><div class="field"><input name="last"></div></div><button type="submit">Send</button></form></main>', 'css/style.css' => '.form{display:grid;grid-template-columns:1fr;gap:1rem}.form .row-2{display:grid;grid-template-columns:1fr 1fr;gap:1rem}.field{display:flex;flex-direction:column;gap:.3rem}@media (max-width:640px){.form .row-2{grid-template-columns:1fr}}'));
 $layoutResult = (new ArtifactCompiler())->compile($layoutArtifact)->toArray();
 $layoutFallback = current(array_filter($layoutResult['fallbacks'] ?? array(), static fn(array $fallback): bool => 'html_form_fallback' === ($fallback['diagnostic_code'] ?? null)));
diff --git a/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction-base64.json b/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction-base64.json
index b375ca3d0..91b2d4b34 100644
--- a/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction-base64.json
+++ b/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction-base64.json
@@ -26,7 +26,7 @@
   "expect": [
     { "path": "status", "assert": "equals", "value": "success" },
     { "path": "assets", "assert": "count", "count": 2 },
-    { "path": "assets.0.path", "assert": "equals", "value": "assets/css/engine-support-before-author-6a4e3baf682b4073.css" },
+    { "path": "assets.0.path", "assert": "equals", "value": "assets/css/engine-support-before-author-5045bf7d151d9649.css" },
     { "path": "assets.0.source", "assert": "equals", "value": "engine-support" },
     { "path": "assets.0.stylesheet_placement", "assert": "equals", "value": "before-author" },
     { "path": "assets.0.content", "assert": "contains", "value": ":root :where(.blocks-engine-css-owned-grid)>:where(:not(h1,h2,h3,h4,h5,h6)){margin-block-start:0;margin-block-end:0}" },
diff --git a/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction.json b/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction.json
index 740787670..6d3918fca 100644
--- a/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction.json
+++ b/php-transformer/tests/fixtures/parity/artifact-inline-style-extraction.json
@@ -26,7 +26,7 @@
   "expect": [
     { "path": "status", "assert": "equals", "value": "success" },
     { "path": "assets", "assert": "count", "count": 2 },
-    { "path": "assets.0.path", "assert": "equals", "value": "assets/css/engine-support-before-author-6a4e3baf682b4073.css" },
+    { "path": "assets.0.path", "assert": "equals", "value": "assets/css/engine-support-before-author-5045bf7d151d9649.css" },
     { "path": "assets.0.source", "assert": "equals", "value": "engine-support" },
     { "path": "assets.0.stylesheet_placement", "assert": "equals", "value": "before-author" },
     { "path": "assets.0.content", "assert": "contains", "value": ":root :where(.blocks-engine-css-owned-grid)>:where(:not(h1,h2,h3,h4,h5,h6)){margin-block-start:0;margin-block-end:0}" },
diff --git a/php-transformer/tests/unit/css-rule-analyzer.php b/php-transformer/tests/unit/css-rule-analyzer.php
index 1aecf0c8e..9ed3e1351 100644
--- a/php-transformer/tests/unit/css-rule-analyzer.php
+++ b/php-transformer/tests/unit/css-rule-analyzer.php
@@ -78,6 +78,28 @@
 $commentMatch = CssSelectorMatcher::matches($commentInput, $commentRule['parsed_selector'] ?? array());
 $assert('.field input' === ($commentRule['selector'] ?? null) && $commentMatch['supported'] && $commentMatch['matches'], 'comments separating identifier-like selector tokens retain descendant boundaries');
 
+$sourceMapCommentAnalysis = (new CssRuleAnalyzer())->analyze(
+    array( array( 'content' => ".field{display:grid}\n/*# sourceMappingURL=site.css.map */", 'source_path' => 'source-map.css', 'source_hash' => hash('sha256', 'source-map.css') ) ),
+    '',
+    array( 'display' ),
+    1024,
+    16,
+    16,
+    4
+);
+$assert(1 === count($sourceMapCommentAnalysis['rules']) && ! in_array('malformed_stylesheet:source-map.css', $sourceMapCommentAnalysis['diagnostics'], true), 'accepts a complete trailing source-map comment as browser-valid stylesheet trivia');
+
+$unterminatedCommentAnalysis = (new CssRuleAnalyzer())->analyze(
+    array( array( 'content' => '.field{display:grid}/* source map', 'source_path' => 'unterminated.css', 'source_hash' => hash('sha256', 'unterminated.css') ) ),
+    '',
+    array( 'display' ),
+    1024,
+    16,
+    16,
+    4
+);
+$assert(in_array('malformed_stylesheet:unterminated.css', $unterminatedCommentAnalysis['diagnostics'], true), 'retains malformed stylesheet diagnostics for unterminated trailing comments');
+
 $unrelatedCss = '';
 for ( $index = 0; $index < 1200; ++$index ) {
     $unrelatedCss .= '.unrelated-' . $index . '{display:grid}';
diff --git a/php-transformer/tests/unit/source-dom.php b/php-transformer/tests/unit/source-dom.php
index ea971193e..34f6a61a3 100644
--- a/php-transformer/tests/unit/source-dom.php
+++ b/php-transformer/tests/unit/source-dom.php
@@ -134,6 +134,18 @@
     'a non-image data URL is rejected even on src'
 );
 
+// --- strict inline SVG payloads ---------------------------------------------
+
+$assert(SourceDom::isSafeInlineSvgMarkup('<svg viewBox="0 0 20 20"><path d="M1 1h18v18H1z"/></svg>'), 'a passive globe SVG is accepted as inline markup');
+$assert(SourceDom::isSafeInlineSvgMarkup('<svg width="20" height="20" viewBox="0 0 20 20"><path d="M4 7l6 6 6-6"/></svg>'), 'a 20px intrinsic chevron SVG is accepted without conflating CSS presentation size');
+$assert(! SourceDom::isSafeInlineSvgMarkup('<svg><a href="java&#x73;cript:alert(1)"><text>Click</text></a></svg>'), 'an entity-encoded javascript SVG link is rejected');
+$assert(! SourceDom::isSafeInlineSvgMarkup('<svg><path d="M0 0"/></svg><div>extra root</div>'), 'SVG markup with an extra HTML root is rejected');
+$assert(! SourceDom::isSafeInlineSvgMarkup('<svg><animate attributeName="href" to="javascript:alert(1)"/></svg>'), 'scriptable SVG animation is rejected');
+$assert(! SourceDom::isSafeInlineSvgMarkup('<svg><set attributeName="href" to="javascript:alert(1)"/></svg>'), 'SVG mutation elements are rejected');
+$assert(! SourceDom::isSafeInlineSvgMarkup('<svg><image href="https://example.test/image.svg"/></svg>'), 'external SVG resources are rejected');
+$assert(! SourceDom::isSafeInlineSvgMarkup('<svg><path fill="url(&#x68;ttps://example.test/paint.svg)" d="M0 0"/></svg>'), 'decoded external paint URLs are rejected');
+$assert(! SourceDom::isSafeInlineSvgMarkup('<!DOCTYPE svg [<!ENTITY payload SYSTEM "file:///etc/passwd">]><svg><path d="M0 0"/></svg>'), 'DOCTYPE and entity declarations are rejected');
+
 // --- statelessness ----------------------------------------------------------
 
 $probe = $element('<div class="a">x</div>');
diff --git a/php-transformer/tools/visual-parity/package.json b/php-transformer/tools/visual-parity/package.json
index bcf1153ad..9c0adbffa 100644
--- a/php-transformer/tools/visual-parity/package.json
+++ b/php-transformer/tools/visual-parity/package.json
@@ -11,7 +11,7 @@
   },
   "scripts": {
     "install:browsers": "playwright install chromium",
-    "test": "node tests/smoke.mjs && node tests/blockquote-margin-reset.mjs && node tests/exact-fit-inline-flow.mjs && node tests/layout-shell-editor-geometry.mjs && node tests/custom-video-host-editor-geometry.mjs && node tests/issue-1493-reduced-public-fixture.mjs && node tests/responsive-document-variants.mjs && node tests/image-custom-host-promotion.mjs && node tests/button-height-ownership.mjs"
+    "test": "node tests/smoke.mjs && node tests/blockquote-margin-reset.mjs && node tests/exact-fit-inline-flow.mjs && node tests/layout-shell-editor-geometry.mjs && node tests/custom-video-host-editor-geometry.mjs && node tests/issue-1493-reduced-public-fixture.mjs && node tests/responsive-document-variants.mjs && node tests/image-custom-host-promotion.mjs && node tests/empty-group-editor-height.mjs && node tests/button-height-ownership.mjs"
   },
   "devDependencies": {
     "playwright": "^1.56.0"
diff --git a/php-transformer/tools/visual-parity/tests/empty-group-editor-height.mjs b/php-transformer/tools/visual-parity/tests/empty-group-editor-height.mjs
new file mode 100644
index 000000000..8a63f915c
--- /dev/null
+++ b/php-transformer/tools/visual-parity/tests/empty-group-editor-height.mjs
@@ -0,0 +1,38 @@
+import assert from 'node:assert/strict';
+import { execFileSync } from 'node:child_process';
+import { chromium } from 'playwright';
+import { fileURLToPath } from 'node:url';
+
+const root = fileURLToPath(new URL('../../../', import.meta.url));
+const result = JSON.parse(execFileSync('php', ['-r', `
+require $argv[1] . '/vendor/autoload.php';
+$result = (new \\Automattic\\BlocksEngine\\PhpTransformer\\HtmlToBlocks\\HtmlTransformer())->transform('<style>.frame{position:relative;height:120px}.source-grid{display:grid;position:absolute;inset:0}.paint{height:auto;container-type:size;background:#eaf0f4}</style><main><div class="frame"><div class="source-grid"><div class="paint"></div></div></div></main>')->toArray();
+echo json_encode(['markup'=>$result['serialized_blocks'], 'css'=>implode("\\n", array_column(array_filter($result['assets'], static fn(array $asset): bool => ($asset['kind'] ?? '') === 'css'), 'content'))]);
+`, root], { encoding: 'utf8' }));
+
+const browser = await chromium.launch({ headless: true });
+try {
+    const page = await browser.newPage();
+    await page.setContent(`<style>${result.css}</style>${result.markup}`);
+    const heights = await page.evaluate(() => {
+        const paint = document.querySelector('.paint');
+        const sourceHeight = paint.getBoundingClientRect().height;
+        const wrapper = document.createElement('div');
+        paint.before(wrapper);
+        wrapper.append(paint);
+        paint.classList.add('wp-block-group__placeholder');
+        paint.setAttribute('data-block', 'fixture');
+        const withoutEditorScope = paint.getBoundingClientRect().height;
+        document.body.classList.add('editor-styles-wrapper');
+        const editorHeight = paint.getBoundingClientRect().height;
+        wrapper.className = 'authored-wrapper';
+        return { sourceHeight, withoutEditorScope, editorHeight, authoredDisplay: getComputedStyle(wrapper).display };
+    });
+    assert.equal(heights.sourceHeight, 120);
+    assert.equal(heights.withoutEditorScope, 0);
+    assert.equal(heights.editorHeight, 120);
+    assert.equal(heights.authoredDisplay, 'block');
+} finally {
+    await browser.close();
+}
+console.log('Empty Group editor height preserved without flattening authored wrappers');