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/components/CreateFlowLockupCardStepShell.tsx

@@ -4,6 +4,7 @@ import type { ReactNode } from "react";
 import { CreateFlowHeaderLockup } from "./CreateFlowHeaderLockup";
 import { CreateFlowStepShell } from "./CreateFlowStepShell";
 import {
+  CREATE_FLOW_MD_CENTERED_SHELL_CLASS,
   CREATE_FLOW_MD_UP_GRID_CELL_CLASS,
   CREATE_FLOW_TWO_COLUMN_MAX_WIDTH_CLASS,
 } from "./createFlowLayoutTokens";
@@ -18,14 +19,18 @@ type CreateFlowLockupCardStepShellProps = {
   children: ReactNode;
 };
 
-/** Final-review layout: `wideGrid`, two columns from `md:`, column widths from `createFlowLayoutTokens`. */
+/** Lockup + card: `wideGrid`, two columns from `md:`, centered in the nav–footer band from `md`. */
 export function CreateFlowLockupCardStepShell({
   lockupTitle,
   lockupDescription,
   children,
 }: CreateFlowLockupCardStepShellProps) {
   return (
-    <CreateFlowStepShell variant="wideGrid" contentTopBelowMd="space-800">
+    <CreateFlowStepShell
+      variant="wideGrid"
+      contentTopBelowMd="space-800"
+      className={CREATE_FLOW_MD_CENTERED_SHELL_CLASS}
+    >
       <div
         className={`mx-auto flex w-full min-w-0 flex-col gap-4 md:grid md:w-full md:grid-cols-2 md:justify-items-center md:gap-[var(--measures-spacing-1200,48px)] ${CREATE_FLOW_TWO_COLUMN_MAX_WIDTH_CLASS}`}
       >