diff --git a/app/components/asset/Icon.tsx b/app/components/asset/Icon.tsx
index cc2b632..cddba05 100644
--- a/app/components/asset/Icon.tsx
+++ b/app/components/asset/Icon.tsx
@@ -1,6 +1,7 @@
 "use client";
 
 import { memo } from "react";
+import ArrowBackIcon from "./icon/arrow_back.svg";
 import ContentCopyIcon from "./icon/content_copy.svg";
 import EditIcon from "./icon/edit.svg";
 import ExclamationIcon from "./icon/exclamation.svg";
@@ -10,6 +11,7 @@ import MailIcon from "./icon/mail.svg";
 import WarningIcon from "./icon/warning.svg";
 
 export const ICON_NAME_OPTIONS = [
+  "arrow_back",
   "chevron_right",
   "content_copy",
   "edit",
@@ -27,6 +29,7 @@ type SvgComponent =
 
 /** SVG import may be a React component or a module object { default: Component } (e.g. with Turbopack) */
 const iconMap: Record<IconName, SvgComponent> = {
+  arrow_back: ArrowBackIcon,
   chevron_right: ChevronRightIcon,
   content_copy: ContentCopyIcon,
   edit: EditIcon,
diff --git a/app/components/asset/icon/arrow_back.svg b/app/components/asset/icon/arrow_back.svg
new file mode 100644
index 0000000..f723bfa
--- /dev/null
+++ b/app/components/asset/icon/arrow_back.svg
@@ -0,0 +1,6 @@
+<svg width="24" height="24" viewBox="0 0 24 24" fill="none" xmlns="http://www.w3.org/2000/svg">
+  <path
+    d="M7.37306 12.75L13.0692 18.4461L12 19.5L4.50003 12L12 4.5L13.0692 5.55383L7.37306 11.25H19.5V12.75H7.37306Z"
+    fill="currentColor"
+  />
+</svg>
diff --git a/app/components/navigation/TopNav/TopNav.view.tsx b/app/components/navigation/TopNav/TopNav.view.tsx
index 9b3ea3b..b99c983 100644
--- a/app/components/navigation/TopNav/TopNav.view.tsx
+++ b/app/components/navigation/TopNav/TopNav.view.tsx
@@ -149,6 +149,12 @@ function TopNavView({
     );
   }
 
+  /**
+   * Standard marketing / app top nav.
+   * Figma: "Navigation / Top" (Community-Rule-System, node 22078-808559) — horizontal
+   * padding, logo ~200px left, menu cluster centered in the bar (`left-1/2` + translate),
+   * log in + create rule on the right. Breakpoints and MenuBar sizes unchanged from prior map.
+   */
   // Render standard variant (Header style)
   return (
     <>
@@ -157,60 +163,79 @@ function TopNavView({
         dangerouslySetInnerHTML={{ __html: JSON.stringify(schemaData) }}
       />
       <header
-        className="sticky top-0 z-50 bg-[var(--color-surface-default-primary)] w-full border-b border-[var(--border-color-default-tertiary)]"
+        className="relative z-50 w-full border-b border-[var(--border-color-default-tertiary)] bg-[var(--color-surface-default-primary)]"
         role="banner"
         aria-label={t("ariaLabels.mainNavigationHeader")}
       >
         <nav
-            className="flex items-center gap-[var(--spacing-scale-002)] sm:justify-between mx-auto
-            h-[var(--spacing-scale-040)]
-            lg:h-auto
-            px-[var(--spacing-scale-016)] py-[var(--spacing-scale-008)]
-            sm:px-[var(--spacing-measures-spacing-016)] sm:py-[var(--spacing-measures-spacing-008)]
+            className="relative flex w-full items-center
+            px-[var(--spacing-scale-016)]
+            py-[var(--spacing-scale-016)]
+            sm:px-[var(--spacing-measures-spacing-016)]
+            sm:py-[var(--spacing-scale-016)]
             lg:px-[var(--spacing-measures-spacing-64,64px)]
-            lg:py-[var(--spacing-scale-020)]
-            xl:py-[var(--spacing-scale-024)]
-            sm:gap-0"
+            lg:py-[var(--spacing-scale-016)]
+            xl:py-[var(--spacing-scale-016)]
+            min-h-[var(--spacing-scale-040)]"
             role="navigation"
             aria-label={t("ariaLabels.mainNavigation")}
         >
-          {/* Logo - Consistent left positioning across all breakpoints */}
-          <Logo
-            size={logoSize}
-            wordmark
-            palette={folderTop ? "inverse" : "default"}
-          />
+          <div
+            className="relative z-20 min-w-0 shrink-0 sm:w-[200px] sm:max-w-[200px] sm:shrink-0"
+            data-topnav="logo"
+          >
+            <Logo
+              size={logoSize}
+              wordmark
+              palette={folderTop ? "inverse" : "default"}
+            />
+          </div>
 
-          {/* Navigation Links - Consistent center positioning */}
-          <div className="flex items-center flex-1 justify-end sm:flex-none sm:justify-center">
-            {/* XSmall breakpoint - Navigation items in Actions section (flex-1, justify-end) */}
-            <div className="block sm:hidden" data-testid="nav-xs">
+          {/* XSmall: nav + login in flow (flex-1) — same as before */}
+          <div
+            className="flex min-w-0 flex-1 items-center justify-end sm:hidden"
+            data-topnav="nav-xs-flow"
+          >
+            <div className="block" data-testid="nav-xs">
               <MenuBar size="X Small">
                 {renderNavigationItems("xsmall")}
                 {logIn && renderLoginButton("xsmall")}
               </MenuBar>
             </div>
+          </div>
 
-            {/* 430-639px (sm: breakpoint): MenuBar X Small */}
-            <div className="hidden sm:block md:hidden" data-testid="nav-sm">
+          {/* sm+ — Figma: nav cluster centered in bar (not between logo and actions) */}
+          <div
+            className="pointer-events-none hidden sm:absolute sm:left-1/2 sm:top-1/2 sm:z-10 sm:flex sm:-translate-x-1/2 sm:-translate-y-1/2 sm:items-center sm:justify-center"
+            data-topnav="nav-center"
+          >
+            <div
+              className="pointer-events-auto hidden sm:flex md:hidden"
+              data-testid="nav-sm"
+            >
               <MenuBar size="X Small">
                 {renderNavigationItems("xsmall")}
                 {logIn && renderLoginButton("xsmall")}
               </MenuBar>
             </div>
-
-            {/* 640-1023px (md: breakpoint): MenuBar X Small (different from folderTop=true) */}
-            <div className="hidden md:block lg:hidden" data-testid="nav-md">
+            <div
+              className="pointer-events-auto hidden md:flex lg:hidden"
+              data-testid="nav-md"
+            >
               <MenuBar size="X Small">
                 {renderNavigationItems("xsmall")}
               </MenuBar>
             </div>
-
-            <div className="hidden lg:block xl:hidden" data-testid="nav-lg">
+            <div
+              className="pointer-events-auto hidden lg:flex xl:hidden"
+              data-testid="nav-lg"
+            >
               <MenuBar size="Large">{renderNavigationItems("large")}</MenuBar>
             </div>
-
-            <div className="hidden xl:block" data-testid="nav-xl">
+            <div
+              className="pointer-events-auto hidden xl:flex"
+              data-testid="nav-xl"
+            >
               <MenuBar size="X Large">
                 {renderNavigationItems("xlarge")}
               </MenuBar>
@@ -218,7 +243,7 @@ function TopNavView({
           </div>
 
           {/* Authentication Elements - Consistent right alignment across all breakpoints */}
-          <div className="flex items-center shrink-0">
+          <div className="relative z-20 ml-auto flex shrink-0 items-center">
             {/* XSmall breakpoint - Only Create Rule button */}
             <div className="block sm:hidden shrink-0" data-testid="auth-xs">
               {renderCreateRuleButton("xsmall", "small", "small")}
diff --git a/app/layout.tsx b/app/layout.tsx
index a961aca..501236a 100644
--- a/app/layout.tsx
+++ b/app/layout.tsx
@@ -1,5 +1,5 @@
 import { Inter, Bricolage_Grotesque, Space_Grotesk } from "next/font/google";
-import type { Metadata } from "next";
+import type { Metadata, Viewport } from "next";
 import type { ReactNode } from "react";
 import { AuthModalProvider } from "./contexts/AuthModalContext";
 import { MessagesProvider } from "./contexts/MessagesContext";
@@ -37,6 +37,12 @@ const spaceGrotesk = Space_Grotesk({
   fallback: ["system-ui", "arial"],
 });
 
+/** Viewport and favicon use the Metadata / Viewport APIs; avoid a manual `<head>` with a second viewport `meta` (duplicates Next’s head injection). */
+export const viewport: Viewport = {
+  width: "device-width",
+  initialScale: 1,
+};
+
 export const metadata: Metadata = {
   title: "CommunityRule - Build operating manuals for successful communities",
   description:
@@ -51,6 +57,9 @@ export const metadata: Metadata = {
     telephone: false,
   },
   metadataBase: new URL("https://communityrule.com"),
+  icons: {
+    icon: [{ url: "/favicon.ico", sizes: "16x16", type: "image/x-icon" }],
+  },
   alternates: {
     canonical: "/",
   },
@@ -87,16 +96,6 @@ export default function RootLayout({ children }: { children: ReactNode }) {
 
   return (
     <html lang="en" className="font-sans">
-      <head>
-        <meta charSet="utf-8" />
-        <meta name="viewport" content="width=device-width, initial-scale=1" />
-        <link
-          rel="icon"
-          href="/favicon.ico"
-          type="image/x-icon"
-          sizes="16x16"
-        />
-      </head>
       <body
         className={`${inter.variable} ${bricolageGrotesque.variable} ${spaceGrotesk.variable}`}
       >
diff --git a/app/not-found.tsx b/app/not-found.tsx
index 720f7b2..7e6e668 100644
--- a/app/not-found.tsx
+++ b/app/not-found.tsx
@@ -1,14 +1,132 @@
+import Link from "next/link";
+import messages from "../messages/en/index";
+import { getTranslation } from "../lib/i18n/getTranslation";
+import { getGovernanceTemplateCatalogEntry } from "../lib/templates/governanceTemplateCatalog";
+import Icon from "./components/asset/Icon";
+import Button from "./components/buttons/Button";
+import HeroDecor from "./components/sections/HeroBanner/HeroDecor";
+
+const NOT_FOUND_TEMPLATE_SLUGS = [
+  "consensus",
+  "do-ocracy",
+  "devolution",
+  "quadratic-governance",
+] as const;
+
+/**
+ * Figma: 404 page frame 22078-808557; 480px lockup 22078-808903; title + CTA group 22078-808908
+ * (filled / Go home left, outline / Browse right, 16px between).
+ * Same [HeroDecor](app/components/sections/HeroBanner/HeroDecor.tsx) SVG as home; 404 places it only behind the title stack.
+ * Shell: [app/layout.tsx](app/layout.tsx) `TopNav` only — no site footer.
+ * Template chip row: Figma 22078-809968 — one row, 16px gaps, 20px to hint (no inner scroll; page handles overflow if needed).
+ * Hero pattern: behind the 404 + bar + h1; wide SVG is painted with overflow-x-clip on `main` so it does not widen the scrollport.
+ */
 export default function NotFound() {
+  const t = (key: string) => getTranslation(messages, key);
+
+  const templateEntries = NOT_FOUND_TEMPLATE_SLUGS.map((slug) =>
+    getGovernanceTemplateCatalogEntry(slug),
+  ).filter(
+    (e): e is NonNullable<typeof e> => e != null,
+  );
+
   return (
-    <div className="min-h-screen bg-[#F4F3F1] flex items-center justify-center">
-      <div className="text-center">
-        <h1 className="text-6xl font-bold text-[var(--color-content-default-primary)] mb-4">
-          404
-        </h1>
-        <p className="text-[var(--color-content-default-secondary)]">
-          Page Not Found
-        </p>
-      </div>
-    </div>
+    <main
+      className="relative flex min-h-0 w-full min-w-0 max-w-full flex-1 flex-col overflow-x-clip bg-[var(--color-surface-default-primary)]"
+      aria-labelledby="not-found-heading"
+    >
+      <div
+        className="relative flex min-h-0 w-full min-w-0 max-w-full flex-1 flex-col overflow-x-clip px-[var(--spacing-scale-008)] sm:px-[var(--spacing-scale-010)] md:px-[var(--spacing-scale-016)] lg:px-[var(--spacing-scale-024)] xl:px-[var(--spacing-scale-048)]"
+      >
+          <div className="relative z-10 flex min-h-0 w-full max-w-full flex-1 flex-col items-center justify-center py-[var(--spacing-scale-040)] sm:py-[var(--spacing-scale-048)]">
+            {/*
+              Vertical rhythm: 22078-808903 + 22078-808908 — 404→bar 8px, bar→h1 32px, h1→body 16px,
+              body→CTAs 48px, CTA→templates 40px (lockup flex gap), template→hint 20px
+            */}
+            <div className="mx-auto flex w-full max-w-[480px] flex-col items-center gap-[var(--spacing-scale-040)] text-center">
+              <div className="flex w-full min-w-0 flex-col items-center">
+                <div className="relative flex w-full flex-col items-center">
+                  <HeroDecor
+                    className="pointer-events-none absolute left-1/2 top-[40%] -z-10 h-[645px] w-[1540px] max-w-none
+                      -translate-x-1/2 -translate-y-1/2
+                      scale-[0.41] sm:scale-[0.45] md:scale-[0.47] lg:scale-[0.5] xl:scale-[0.53]"
+                  />
+                  <p
+                    className="w-full text-center font-bricolage-grotesque font-extrabold leading-none tracking-[-0.04em] text-[clamp(5.5rem,16vw,13.75rem)] text-[var(--color-content-default-brand-primary)]"
+                    aria-hidden="true"
+                  >
+                    {t("pages.notFoundPage.codeTitle")}
+                  </p>
+                  <div
+                    className="mt-[var(--spacing-scale-008)] h-1.5 w-[120px] shrink-0 rounded-full bg-[var(--color-yellow-yellow200)]"
+                    aria-hidden="true"
+                  />
+                  <h1
+                    id="not-found-heading"
+                    className="mt-[var(--spacing-scale-032)] max-w-full text-center font-bricolage-grotesque text-[2.5rem] font-medium leading-[1.1] text-[var(--color-content-default-primary)] min-[400px]:text-[44px] min-[400px]:leading-[1.1]"
+                  >
+                    {t("pages.notFoundPage.heading")}
+                  </h1>
+                </div>
+                <p className="mt-[var(--spacing-scale-016)] w-full max-w-[443px] text-center font-inter text-lg font-normal leading-[1.3] text-[var(--color-content-default-secondary)]">
+                  {t("pages.notFoundPage.description")}
+                </p>
+
+                <div
+                  dir="ltr"
+                  className="mt-[var(--spacing-scale-048)] flex w-full min-w-0 flex-col items-center justify-center gap-[var(--spacing-scale-016)] min-[400px]:flex-nowrap min-[400px]:flex-row min-[400px]:items-center min-[400px]:justify-center"
+                >
+                  <Button
+                    href="/"
+                    size="large"
+                    buttonType="filled"
+                    palette="default"
+                    className="inline-flex w-max max-w-full shrink-0 items-center justify-center gap-[var(--spacing-scale-010)]"
+                  >
+                    <Icon
+                      name="arrow_back"
+                      size={20}
+                      className="shrink-0"
+                    />
+                    {t("pages.notFoundPage.goHomeCta")}
+                  </Button>
+                  <Button
+                    href="/templates"
+                    size="large"
+                    buttonType="outline"
+                    palette="default"
+                    className="inline-flex w-max max-w-full shrink-0 items-center justify-center"
+                  >
+                    {t("pages.notFoundPage.browseTemplatesCta")}
+                  </Button>
+                </div>
+              </div>
+
+              {templateEntries.length > 0 ? (
+                <div className="flex w-full min-w-0 max-w-[36rem] flex-col items-center gap-[var(--spacing-scale-020)] self-stretch">
+                  <div
+                    className="flex w-full min-w-0 max-md:flex-wrap md:flex-nowrap items-center justify-center gap-x-[var(--spacing-scale-016)] gap-y-[var(--spacing-scale-012)]"
+                    role="list"
+                  >
+                    {templateEntries.map((entry) => (
+                      <Link
+                        key={entry.slug}
+                        href={`/create/review-template/${entry.slug}`}
+                        role="listitem"
+                        className={`${entry.backgroundColor} inline-flex h-[37px] shrink-0 items-center justify-center rounded-full px-[20px] py-0 text-center font-bricolage-grotesque text-sm font-extrabold leading-[21px] text-[var(--color-content-invert-primary)] no-underline transition-opacity hover:opacity-90 focus-visible:outline focus-visible:outline-2 focus-visible:outline-offset-2 focus-visible:outline-[var(--color-border-invert-primary)]`}
+                      >
+                        {entry.title}
+                      </Link>
+                    ))}
+                  </div>
+                  <p className="w-full text-center font-inter text-[13px] font-normal leading-[1.2] text-[var(--color-gray-500)]">
+                    {t("pages.notFoundPage.templateHint")}
+                  </p>
+                </div>
+              ) : null}
+            </div>
+          </div>
+        </div>
+      </main>
   );
 }
diff --git a/docs/figma-component-registry.md b/docs/figma-component-registry.md
new file mode 100644
index 0000000..f4cbe5d
--- /dev/null
+++ b/docs/figma-component-registry.md
@@ -0,0 +1,21 @@
+# Figma → component registry
+
+Quick map from the Figma file **Community Rule System** (`agv0VBLiBlcnSAaiAORgPR`) to this repo’s [`app/components/`](/app/components/). Figma uses eleven top-level “❖” areas; `app/components` adds a few app-only buckets (not 1:1 with Figma pages).
+
+| Figma (page) | Code | Notes |
+| --- | --- | --- |
+| [Utility](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=20515-15809) | `utility/` | Create chrome, modals header/footer, tag, scroll, sidebar, dividers, etc. |
+| [Asset](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=1240-9089) | `asset/` + `icons/` | Icons, logos; Avatar component currently under `icons/Avatar.tsx` |
+| [Button](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=497-3016) | `buttons/` | Figma `Button/`; code uses plural folder name. |
+| [Card](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=17865-24349) | `cards/` | Step / rule / icon / selection style cards. |
+| [Control](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=5944-58611) | `controls/` | Inputs, toggles, select, switch, upload, etc. |
+| [Layout](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=21836-20542) | `layout/` | List / list entry / list edit. |
+| [Modals](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=5944-47704) | `modals/` | Alert, create, dialog, login, tooltip, context menu, … |
+| [Navigation](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=5944-69518) | `navigation/` | Top nav, footer, menu bar, link. |
+| [Progress](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=21163-24443) | `progress/` | Stepper, proportion bar. |
+| [Sections](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=17865-24546) | `sections/` | Page-level / marketing-style compositions. |
+| [Type](https://www.figma.com/design/agv0VBLiBlcnSAaiAORgPR/Community-Rule-System?node-id=21473-29498) | `type/` | Some “section header” / lockup patterns also live in `sections/`; check both. |
+| — | `content/` | Not a Figma DS page; app content shells / thumbnails. |
+| — | `localization/` | Not a Figma DS page; i18n UI. |
+
+*Update this when you add a new top-level `app/components/*` package or a new Figma canvas.*
diff --git a/messages/en/index.ts b/messages/en/index.ts
index 0c54a8b..62495fb 100644
--- a/messages/en/index.ts
+++ b/messages/en/index.ts
@@ -18,6 +18,7 @@ import learn from "./pages/learn.json";
 import monitor from "./pages/monitor.json";
 import login from "./pages/login.json";
 import profile from "./pages/profile.json";
+import notFoundPage from "./pages/notFoundPage.json";
 import navigation from "./navigation.json";
 import metadata from "./metadata.json";
 
@@ -72,6 +73,7 @@ export default {
     monitor,
     login,
     profile,
+    notFoundPage,
   },
   create: {
     community: {
diff --git a/messages/en/pages/notFoundPage.json b/messages/en/pages/notFoundPage.json
new file mode 100644
index 0000000..3a43be7
--- /dev/null
+++ b/messages/en/pages/notFoundPage.json
@@ -0,0 +1,9 @@
+{
+  "_comment": "Global 404 — Figma 22078-808557",
+  "codeTitle": "404",
+  "heading": "Page not found",
+  "description": "Looks like this page didn't make it to a consensus. It may have moved, been removed, or never existed.",
+  "goHomeCta": "Go back home",
+  "browseTemplatesCta": "Browse templates",
+  "templateHint": "Maybe one of these templates can help?"
+}
diff --git a/tests/e2e/visual-regression.spec.ts-snapshots/404-error-chromium.png b/tests/e2e/visual-regression.spec.ts-snapshots/404-error-chromium.png
index 12e50b5..5f12ae0 100644
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diff --git a/tests/e2e/visual-regression.spec.ts-snapshots/404-error-webkit.png b/tests/e2e/visual-regression.spec.ts-snapshots/404-error-webkit.png
index 49d98da..e93946c 100644
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