Center lockup-plus-card and card-stack create-flow steps in the nav–footer band so they are not stuck under the header when the content is shorter than the viewport.

Co-authored-by: Cursor <cursoragent@cursor.com>

app/(app)/create/CreateFlowLayoutClient.tsx

@@ -70,6 +70,7 @@ import {
   CREATE_FLOW_FOOTER_BUTTON_CLASS,
   CREATE_FLOW_FOOTER_BUTTON_ON_DARK_CLASS,
 } from "./utils/createFlowFooterClassNames";
+import { CREATE_FLOW_MD_CENTERED_MAIN_CLASS } from "./components/createFlowLayoutTokens";
 import {
   CUSTOM_RULE_CONFIRM_FOOTER_STEP_BY_STEP,
   methodCardFacetSectionForConfirmStep,
@@ -467,13 +468,13 @@ function CreateFlowLayoutContent({
   );
   const stepIdx = currentStep != null ? getStepIndex(currentStep) : -1;
 
-  /** At `md+`, main cross-axis: center by default; exceptions stay top-aligned (see product spec). */
+  /** Lockup+card / card-stack: `items-start` + shell `my-auto` so overflow scrolls from the top. */
   const mainContentClass = isCompletedStep
     ? "items-stretch overflow-y-auto md:overflow-hidden"
     : isSelectSplitScrollStep
       ? "items-start justify-start overflow-y-auto max-lg:overflow-y-auto lg:min-h-0 lg:items-stretch lg:overflow-hidden"
-      : isFinalReviewLike || isCardLayoutStep || isTemplateReviewRoute
-        ? "items-start justify-center overflow-y-auto"
+      : isTemplateReviewRoute || isFinalReviewLike || isCardLayoutStep
+        ? CREATE_FLOW_MD_CENTERED_MAIN_CLASS
         : "items-start justify-center overflow-y-auto md:items-center";
 
   const isTextStep = createFlowStepUsesCenteredTextLayout(currentStep);