diff --git a/frontend/apps/artcraft-website-next/DESIGN.md b/frontend/apps/artcraft-website-next/DESIGN.md
new file mode 100644
index 0000000000..3aa9cf454d
--- /dev/null
+++ b/frontend/apps/artcraft-website-next/DESIGN.md
@@ -0,0 +1,59 @@
+# Design Ideology
+
+The working philosophy behind the ArtCraft marketing site
+(`artcraft-website-next`). This captures direction and standards, not a
+finished visual spec — the aesthetic itself is still under experiment.
+
+## What we are building
+
+A product website with a sales/marketing angle. The bar: it should read as
+a professionally developed, premium site with a design language that
+belongs to ArtCraft — not a template, not AI-slop defaults, and not a
+studio/agency showpiece. Creative technology (Three.js, GSAP, smooth
+scroll) is welcome and encouraged, but subordinated to selling the
+product: used where it deepens the product story, never as decoration for
+its own sake, and never overdone.
+
+## The premium principle
+
+Premium is felt immediately, and it is built from accumulated small
+details — not from one big idea. Small details make a big difference.
+
+- **One or two elements are never enough.** A single hero gimmick floating
+  in unoccupied space reads amateur and unfinished — the "blank/empty
+  negative space" failure. Compositions need layered density: many quiet,
+  coordinated details rather than one loud one.
+- **Negative space must be structured, not merely empty.** Rails, rules,
+  ticks, annotations, and measurements make emptiness intentional.
+- **Everything is choreographed.** Nothing just appears; elements arrive
+  with easing and stagger. Motion that maps to scroll is scrub-linked and
+  reversible.
+- **Finish every surface.** Raw flat color, unlit 3D, and default
+  materials read as demos. Grain, lighting, shadow, vignette, and
+  micro-contrast are the difference between blocked-out and finished.
+- **One voice for micro-detail.** Annotations, counters, tick marks, and
+  labels share a single vocabulary (mono uppercase HUD labels, hairline
+  rules, crosshair ticks) so density never becomes noise.
+
+## Current experimental language (subject to change)
+
+Brutalist/instrument direction. Nothing here is final; treat every item as
+a hypothesis under test, replaceable by a better experiment:
+
+- Two themes, one structure: dark "viewport" (near-black terminal), light
+  "blueprint" (warm paper). Light-dominant positioning, deliberately apart
+  from dark competitors.
+- Hard edges, zero border radius, hairline rules, ticked 1280px rails.
+- Type: Archivo display (stretched), Instrument Serif italic for one
+  contrast word per headline, Inter body, Geist Mono for HUD micro-labels.
+- One blue accent, used sparingly. Color discipline over rainbow.
+
+## Working practices
+
+- **Experiments over debates.** Contested aesthetics get built behind the
+  dev tuner and judged on the page, not argued in the abstract.
+- **Every tweakable constant is registered with the tuner** (see
+  TUNER.md). A missing slider costs a whole build round-trip.
+- **Progressive enhancement is non-negotiable.** Reduced motion, coarse
+  pointers, no-JS crawlers, and WebGL failure all receive a complete,
+  legible page.
diff --git a/frontend/apps/artcraft-website-next/TUNER.md b/frontend/apps/artcraft-website-next/TUNER.md
index 4086adbea9..52bed09056 100644
--- a/frontend/apps/artcraft-website-next/TUNER.md
+++ b/frontend/apps/artcraft-website-next/TUNER.md
@@ -37,11 +37,22 @@ iteration/build round-trip.
 import { defineTunables } from "@/lib/tuner";
 
 export const glowTuner = defineTunables("glow", "Glow", {
-  radius: { label: "Radius px", min: 0, max: 400, step: 5, default: 120 },
-  strength: { label: "Strength", min: 0, max: 2, step: 0.05, default: 0.8 },
+  radius: {
+    label: "Radius px", min: 0, max: 400, step: 5, default: 120,
+    info: "Blur radius of the glow behind the hero card.",
+  },
+  strength: {
+    label: "Strength", min: 0, max: 2, step: 0.05, default: 0.8,
+    info: "Peak intensity of the glow (0 = off).",
+  },
 });
 ```
 
+**Every tunable must carry an `info` one-liner.** It renders as the row's
+`i`-mark hover in the panel — a slider nobody can decipher ("Ghost alpha"?)
+costs more than the sentence explaining it. Write what the knob visibly
+does, not what the variable is named.
+
 Then read values where they're used:
 
 - **Per-frame consumers** (`useFrame`, rAF loops): call `glowTuner.read()`
@@ -52,8 +63,9 @@ Then read values where they're used:
   `hero-wall.tsx`).
 
 The panel picks up new groups automatically — no panel changes needed.
-Registered groups: Wall layout, Wall motion, Wall look (all for the hero
-render wall; see `src/components/landing/hero-tunables.ts`).
+Registered groups: Wall layout, Wall motion, Wall look (hero render wall;
+`src/components/landing/hero-tunables.ts`) and Ruler layout, Ruler motion,
+Ruler look (scroll ruler; `src/components/ruler/ruler-tunables.ts`).
 
 ## Shipping tuned values
 
diff --git a/frontend/apps/artcraft-website-next/next.config.ts b/frontend/apps/artcraft-website-next/next.config.ts
index f1b0100002..54e7d572cf 100644
--- a/frontend/apps/artcraft-website-next/next.config.ts
+++ b/frontend/apps/artcraft-website-next/next.config.ts
@@ -2,12 +2,18 @@ import type { NextConfig } from "next";
 
 const nextConfig: NextConfig = {
   reactStrictMode: true,
-  // Same-origin proxy for large media served from the live site. The hero
-  // rail draws these as WebGL video textures, which need CORS-clean
-  // sources — getartcraft.com serves its videos without
-  // Access-Control-Allow-Origin, so we route them through our own origin.
+  // Same-origin proxies for large media served from other origins. The hero
+  // wall draws its clips as WebGL video textures, which need CORS-clean
+  // sources, and neither CDN sends Access-Control-Allow-Origin, so those
+  // requests route through our own origin.
   async rewrites() {
     return [
+      // Showcase clips for the hero wall (see cdnMediaUrl in lib/links.ts).
+      {
+        source: "/cdn-media/:path*",
+        destination: "https://frontend-cdn.fakeyou.com/:path*",
+      },
+      // Feature footage and other assets still hosted on the live site.
       {
         source: "/ext-media/:path*",
         destination: "https://getartcraft.com/:path*",
diff --git a/frontend/apps/artcraft-website-next/src/app/globals.css b/frontend/apps/artcraft-website-next/src/app/globals.css
index 5d2db3e7e5..4b922a0efb 100644
--- a/frontend/apps/artcraft-website-next/src/app/globals.css
+++ b/frontend/apps/artcraft-website-next/src/app/globals.css
@@ -195,6 +195,47 @@ body {
   height: 1px;
 }
 
+/* Scroll ruler. JS stamps data-ruler on <html> when the instrument mounts
+   (capable device only), so no-JS visitors and small/coarse-pointer devices
+   keep their native scrollbar untouched. "on" = full instrument (native
+   scrollbar hidden); "static" = reduced-motion rail (scrollbar stays).
+   Either way the rail's gutter is reserved on main/footer — the nav stays
+   full-bleed and simply overlaps the rail's top. */
+html[data-ruler="on"] {
+  scrollbar-width: none;
+}
+html[data-ruler="on"]::-webkit-scrollbar {
+  display: none;
+  width: 0;
+  height: 0;
+}
+html[data-ruler][data-ruler-side="right"] main,
+html[data-ruler][data-ruler-side="right"] footer {
+  padding-right: var(--ruler-rail, 48px);
+}
+html[data-ruler][data-ruler-side="left"] main,
+html[data-ruler][data-ruler-side="left"] footer {
+  padding-left: var(--ruler-rail, 48px);
+}
+
+/* Rolling odometer for the ruler's percent readout. Digit columns translate
+   by whole digits; the reduced-motion blanket below disables the roll. */
+.ruler-digits {
+  display: inline-flex;
+  height: 1em;
+  overflow: hidden;
+  line-height: 1;
+}
+.ruler-digit-col {
+  display: flex;
+  flex-direction: column;
+  transition: transform 280ms cubic-bezier(0.2, 0.9, 0.2, 1);
+}
+.ruler-digit-col > span {
+  display: block;
+  height: 1em;
+}
+
 /* Mono capability marquee. Duplicated track scrolls -50%; the reduced-motion
  * blanket below freezes it in place. */
 .marquee {
diff --git a/frontend/apps/artcraft-website-next/src/app/layout.tsx b/frontend/apps/artcraft-website-next/src/app/layout.tsx
index a877bc451c..fecfc1e5b0 100644
--- a/frontend/apps/artcraft-website-next/src/app/layout.tsx
+++ b/frontend/apps/artcraft-website-next/src/app/layout.tsx
@@ -9,6 +9,7 @@ import {
 import SiteNav from "@/components/site-nav";
 import SiteFooter from "@/components/site-footer";
 import MotionProvider from "@/components/motion-provider";
+import ScrollRuler from "@/components/ruler/scroll-ruler";
 import TunerPanel from "@/components/dev/tuner-panel";
 import "./globals.css";
 
@@ -121,8 +122,9 @@ export default function RootLayout({
         />
         <MotionProvider>
           <SiteNav />
-          <main>{children}</main>
+          <main id="main">{children}</main>
           <SiteFooter />
+          <ScrollRuler />
         </MotionProvider>
         <TunerPanel />
       </body>
diff --git a/frontend/apps/artcraft-website-next/src/components/dev/tuner-panel.tsx b/frontend/apps/artcraft-website-next/src/components/dev/tuner-panel.tsx
index b998d8a6e6..7b4a868a1a 100644
--- a/frontend/apps/artcraft-website-next/src/components/dev/tuner-panel.tsx
+++ b/frontend/apps/artcraft-website-next/src/components/dev/tuner-panel.tsx
@@ -197,17 +197,37 @@ function Row({
   const value = useTunerStore((s) => s.values[storeKey] ?? def.default);
   const setValue = useTunerStore((s) => s.setValue);
   const modified = value !== def.default;
+  const [showInfo, setShowInfo] = useState(false);
 
   return (
     <label className="flex flex-col gap-1">
-      <span className="flex items-center justify-between">
+      <span className="relative flex items-center justify-between">
         <span
-          className={`font-mono text-[10px] tracking-[0.08em] uppercase ${
+          className={`flex items-center gap-1 font-mono text-[10px] tracking-[0.08em] uppercase ${
             modified ? "text-accent-ink" : "text-muted"
           }`}
         >
           {def.label}
+          {def.info && (
+            <span
+              aria-label={def.info}
+              onMouseEnter={() => setShowInfo(true)}
+              onMouseLeave={() => setShowInfo(false)}
+              // A click on anything inside <label> would focus the number
+              // input — the mark is informational, so swallow it.
+              onClick={(e) => e.preventDefault()}
+              onPointerDown={(e) => e.preventDefault()}
+              className="inline-flex h-3 w-3 cursor-help items-center justify-center border border-line text-[8px] leading-none text-faint normal-case"
+            >
+              i
+            </span>
+          )}
         </span>
+        {def.info && showInfo && (
+          <span className="pointer-events-none absolute inset-x-0 top-full z-10 mt-1 border border-line-strong bg-bg-raised p-2 font-mono text-[10px] leading-snug tracking-normal normal-case text-ink shadow-[0_4px_16px_rgba(0,0,0,0.3)]">
+            {def.info}
+          </span>
+        )}
         <input
           type="number"
           value={round(value)}
diff --git a/frontend/apps/artcraft-website-next/src/components/landing/final-cta.tsx b/frontend/apps/artcraft-website-next/src/components/landing/final-cta.tsx
index 6b252b454c..3545d73a3e 100644
--- a/frontend/apps/artcraft-website-next/src/components/landing/final-cta.tsx
+++ b/frontend/apps/artcraft-website-next/src/components/landing/final-cta.tsx
@@ -4,7 +4,7 @@ import { SectionShell } from "./section-shell";
 
 export default function FinalCta() {
   return (
-    <SectionShell>
+    <SectionShell id="start">
       <div className="flex flex-col items-center px-6 py-20 text-center md:py-28">
         <p className="hud-label text-faint">Free to start · No subscription</p>
         <h2
diff --git a/frontend/apps/artcraft-website-next/src/components/landing/hero-tunables.ts b/frontend/apps/artcraft-website-next/src/components/landing/hero-tunables.ts
index d7d2b207f3..aa04b72b3e 100644
--- a/frontend/apps/artcraft-website-next/src/components/landing/hero-tunables.ts
+++ b/frontend/apps/artcraft-website-next/src/components/landing/hero-tunables.ts
@@ -9,25 +9,42 @@ export const wallLayoutTuner = defineTunables("wallLayout", "Wall layout", {
   rowHeight: {
     label: "Near row × vh",
     min: 0.14,
-    max: 0.42,
+    max: 0.55,
     step: 0.01,
-    default: 0.31,
+    default: 0.33,
+    info: "Panel height of the near row, as a fraction of the viewport height.",
   },
   rowScale: {
     label: "Row shrink",
     min: 0.5,
     max: 1,
     step: 0.01,
-    default: 0.78,
+    default: 0.73,
+    info: "How much each deeper row's panels shrink relative to the row in front.",
+  },
+  gap: {
+    label: "Gap px",
+    min: 8,
+    max: 80,
+    step: 1,
+    default: 25,
+    info: "Horizontal gap between panels within a row.",
+  },
+  zStep: {
+    label: "Row z step px",
+    min: 0,
+    max: 400,
+    step: 5,
+    default: 170,
+    info: "Depth distance between successive rows of the wall.",
   },
-  gap: { label: "Gap px", min: 8, max: 80, step: 1, default: 22 },
-  zStep: { label: "Row z step px", min: 0, max: 400, step: 5, default: 170 },
   yNear: {
     label: "Near row y × vh",
     min: -0.5,
     max: 0.5,
     step: 0.01,
     default: -0.17,
+    info: "Vertical position of the near row, in viewport heights from center.",
   },
   yMid: {
     label: "Mid row y × vh",
@@ -35,19 +52,42 @@ export const wallLayoutTuner = defineTunables("wallLayout", "Wall layout", {
     max: 0.5,
     step: 0.01,
     default: 0.17,
+    info: "Vertical position of the mid row, in viewport heights from center.",
   },
 });
 
 export const wallMotionTuner = defineTunables("wallMotion", "Wall motion", {
-  yawDeg: { label: "Yaw °", min: -35, max: 35, step: 0.5, default: -11 },
-  pitchDeg: { label: "Pitch °", min: -12, max: 12, step: 0.25, default: 2.5 },
-  speed: { label: "Drift px/s", min: 0, max: 240, step: 2, default: 42 },
+  yawDeg: {
+    label: "Yaw °",
+    min: -35,
+    max: 35,
+    step: 0.5,
+    default: -11,
+    info: "Resting sideways rotation of the whole wall.",
+  },
+  pitchDeg: {
+    label: "Pitch °",
+    min: -12,
+    max: 12,
+    step: 0.25,
+    default: 2.5,
+    info: "Resting up/down rotation of the whole wall.",
+  },
+  speed: {
+    label: "Drift px/s",
+    min: 0,
+    max: 240,
+    step: 2,
+    default: 42,
+    info: "Unattended sideways drift speed of the near row.",
+  },
   speedStep: {
     label: "Row parallax",
     min: 0.3,
     max: 1,
     step: 0.02,
     default: 0.62,
+    info: "Depth parallax: each deeper row moves this fraction of the row in front.",
   },
   dragMax: {
     label: "Max throw px/s",
@@ -55,27 +95,65 @@ export const wallMotionTuner = defineTunables("wallMotion", "Wall motion", {
     max: 6000,
     step: 100,
     default: 2400,
+    info: "Speed cap on the momentum a drag can throw the wall with.",
+  },
+  introBurst: {
+    label: "Intro burst ×",
+    min: 1,
+    max: 40,
+    step: 1,
+    default: 16,
+    info: "Multiple of the drift speed the wall sweeps in with on load before easing down.",
   },
-  introBurst: { label: "Intro burst ×", min: 1, max: 40, step: 1, default: 16 },
   parallax: {
     label: "Pointer tilt rad",
     min: 0,
     max: 0.09,
     step: 0.002,
     default: 0.024,
+    info: "How far the pointer position tilts the whole wall.",
   },
 });
 
 export const wallLookTuner = defineTunables("wallLook", "Wall look", {
-  dimNear: { label: "Near row dim", min: 0, max: 1, step: 0.02, default: 0.86 },
-  dimMid: { label: "Mid row dim", min: 0, max: 1, step: 0.02, default: 0.7 },
-  washLight: { label: "Light wash", min: 0, max: 1, step: 0.02, default: 0.15 },
-  edgeFade: { label: "Edge fade", min: 0, max: 1, step: 0.02, default: 0.65 },
+  dimNear: {
+    label: "Near row dim",
+    min: 0,
+    max: 1,
+    step: 0.02,
+    default: 0.86,
+    info: "Brightness of the near row's footage (1 = full strength).",
+  },
+  dimMid: {
+    label: "Mid row dim",
+    min: 0,
+    max: 1,
+    step: 0.02,
+    default: 0.7,
+    info: "Brightness of the mid row's footage — deeper rows recede into the background.",
+  },
+  washLight: {
+    label: "Light wash",
+    min: 0,
+    max: 1,
+    step: 0.02,
+    default: 0.15,
+    info: "Light theme only: how much deeper rows wash toward the paper via opacity.",
+  },
+  edgeFade: {
+    label: "Edge fade",
+    min: 0,
+    max: 1,
+    step: 0.02,
+    default: 0.65,
+    info: "How strongly panels vignette out toward the viewport's left/right edges.",
+  },
   frameAlpha: {
     label: "Frame alpha",
     min: 0,
     max: 1,
     step: 0.02,
-    default: 0.9,
+    default: 0.18,
+    info: "Opacity of the hairline frames around each panel.",
   },
 });
diff --git a/frontend/apps/artcraft-website-next/src/components/landing/hero-wall.tsx b/frontend/apps/artcraft-website-next/src/components/landing/hero-wall.tsx
index 22946a683e..caf6462768 100644
--- a/frontend/apps/artcraft-website-next/src/components/landing/hero-wall.tsx
+++ b/frontend/apps/artcraft-website-next/src/components/landing/hero-wall.tsx
@@ -44,6 +44,29 @@ export function createWallDrag(): WallDrag {
 const ROW_COUNT = 2;
 const FOV = 30; // must match FittedCamera in hero-wordmark.tsx
 
+// Decode budget. A wall of 1080p clips all decoding at once is what makes
+// the hero feel heavy, so only the clips whose panels are near the viewport
+// keep a decoder; the rest pause on their last frame (already invisible
+// behind the edge vignette). Playback decisions run on their own slow tick,
+// since play/pause churn at 60 Hz would cost more than it saves, and a clip
+// holds its slot briefly after leaving so one hovering at the edge does not
+// stutter. Panels beyond CULL_EDGE half-widths are fully off screen: a panel
+// is clear of the edge once its center passes ~1.25.
+const CULL_EDGE = 1.4;
+const CULL_TICK_S = 0.25;
+const CULL_HOLD_S = 1.2;
+const MAX_DECODING = 12;
+// Starting a decoder is the expensive moment (demux, buffer, first keyframe),
+// so only a couple are started per tick. Scrolling back to the hero would
+// otherwise restart a dozen at once and hitch the frame it lands on; instead
+// the wall refills over about a second, behind the panels' own fade-in.
+const RESUME_PER_TICK = 3;
+// Grace period before a scrolled-away wall gives up its decoders. The frame
+// loop is already stopped by then, so a few seconds of idle decoding is
+// cheaper than the restart a quick scroll down and back would otherwise pay.
+const PARK_DELAY_MS = 2500;
+const FAR_EDGE = 1e6; // stand-in distance for a clip with no panel this frame
+
 type WallPanel = {
   clip: number;
   w: number;
@@ -64,10 +87,14 @@ export default function HeroWall({
   pointer,
   drag,
   colors,
+  onScreen,
 }: {
   pointer: React.RefObject<{ x: number; y: number; active: boolean }>;
   drag: React.RefObject<WallDrag>;
   colors: ThemeColors;
+  // False once the hero has scrolled away or the tab went to the background.
+  // The frame loop is stopped then, so playback is parked from an effect.
+  onScreen: boolean;
 }) {
   const size = useThree((s) => s.size);
   const rigRef = useRef<THREE.Group>(null);
@@ -77,6 +104,7 @@ export default function HeroWall({
     speed: 0,
     wasDragging: false,
     started: false,
+    cullTimer: 0,
   });
   const tilt = useRef({ x: 0, y: 0 });
 
@@ -95,7 +123,11 @@ export default function HeroWall({
         v.loop = true;
         v.playsInline = true;
         v.crossOrigin = "anonymous";
-        v.preload = "auto";
+        v.disableRemotePlayback = true;
+        // Metadata only: fetching every clip up front stalls the whole page
+        // on load. The decode budget below calls play() as panels approach,
+        // which pulls each clip down roughly in the order it is needed.
+        v.preload = "metadata";
         return v;
       }),
     [],
@@ -133,7 +165,6 @@ export default function HeroWall({
         v.src = SEEDANCE_SHOWCASE[i].src;
         v.load();
       }
-      v.play().catch(() => {});
     });
     return () => {
       textures.forEach((t) => t.dispose());
@@ -145,6 +176,18 @@ export default function HeroWall({
     };
   }, [videos, textures]);
 
+  // Scrolled away or backgrounded: the frame loop is stopped, so nothing
+  // would ever pause these. Park them all after a grace period; the budget
+  // re-grants slots on the first frame after the hero comes back.
+  useEffect(() => {
+    if (onScreen) return;
+    const timer = setTimeout(
+      () => videos.forEach((v) => v.pause()),
+      PARK_DELAY_MS,
+    );
+    return () => clearTimeout(timer);
+  }, [onScreen, videos]);
+
   // Layout tunables change the wall's structure — debounce a rebuild.
   const [layoutVersion, setLayoutVersion] = useState(0);
   useEffect(() => {
@@ -170,7 +213,7 @@ export default function HeroWall({
   // pool, so no clip ever appears in more than one row.
   const layout = useMemo(() => {
     const t = wallLayoutTuner.read();
-    const nearH = Math.min(320, Math.max(110, size.height * t.rowHeight));
+    const nearH = Math.min(460, Math.max(110, size.height * t.rowHeight));
     const yFracs = [t.yNear, t.yMid];
     const clipCount = SEEDANCE_SHOWCASE.length;
     const perRow = Math.floor(clipCount / ROW_COUNT);
@@ -267,6 +310,19 @@ export default function HeroWall({
     [layout],
   );
 
+  // Per-clip decode bookkeeping, reused every frame so the budget allocates
+  // nothing: closest panel edge, seconds since the clip last held a slot,
+  // and a scratch permutation the budget sorts in place.
+  const clipEdge = useMemo(
+    () => new Float32Array(SEEDANCE_SHOWCASE.length).fill(FAR_EDGE),
+    [],
+  );
+  const clipIdle = useMemo(
+    () => new Float32Array(SEEDANCE_SHOWCASE.length),
+    [],
+  );
+  const clipOrder = useMemo(() => SEEDANCE_SHOWCASE.map((_, i) => i), []);
+
   useFrame((st3, delta) => {
     const dt = Math.min(delta, 0.05);
     const st = state.current;
@@ -320,6 +376,7 @@ export default function HeroWall({
     const cosY = Math.cos(yaw);
     const sinY = Math.sin(yaw);
     const dims = [lk.dimNear, lk.dimMid];
+    clipEdge.fill(FAR_EDGE);
 
     for (let i = 0; i < layout.panels.length; i++) {
       const g = groupRefs.current[i];
@@ -342,6 +399,7 @@ export default function HeroWall({
       const projX = wx * (dist / (dist - wz));
       const edge = Math.abs(projX) / (size.width / 2);
       const vig = 1 - lk.edgeFade * smoothstep(0.72, 1.3, edge);
+      if (edge < clipEdge[c.clip]) clipEdge[c.clip] = edge;
 
       const ready = videos[c.clip].readyState >= 2 ? 1 : 0;
       videoAlpha[i] += (ready - videoAlpha[i]) * (1 - Math.exp(-3 * dt));
@@ -352,8 +410,11 @@ export default function HeroWall({
       const dim = dims[c.row];
       const mat = materials[i];
       if (dark) {
-        mat.color.setScalar(dim * vig * va);
-        mat.opacity = intro;
+        // Fade the unloaded panel out with alpha, not toward black: clips
+        // now load on demand, and an opaque black rectangle reads as a hole
+        // in the wall against the dark background.
+        mat.color.setScalar(dim * vig);
+        mat.opacity = intro * va;
       } else {
         // Light theme recedes via opacity toward the paper — but only for
         // depth: the near row keeps nearly full ink (sqrt softens its dim)
@@ -364,6 +425,12 @@ export default function HeroWall({
       }
       frameMaterials[i].opacity = lk.frameAlpha * vig * intro;
     }
+
+    st.cullTimer -= dt;
+    if (st.cullTimer <= 0) {
+      st.cullTimer = CULL_TICK_S;
+      applyDecodeBudget(videos, clipEdge, clipIdle, clipOrder, CULL_TICK_S);
+    }
   });
 
   return (
@@ -386,3 +453,35 @@ export default function HeroWall({
     </group>
   );
 }
+
+// Hand the scarce decoders to the clips nearest the viewport and pause the
+// rest. Clips are ranked by their closest panel, so when the cap bites it is
+// always the outermost panels that freeze: the ones the edge vignette has
+// already dissolved. `elapsed` is the time since the previous call, not the
+// frame delta: this runs on the cull tick, not every frame.
+function applyDecodeBudget(
+  videos: HTMLVideoElement[],
+  clipEdge: Float32Array,
+  clipIdle: Float32Array,
+  clipOrder: number[],
+  elapsed: number,
+) {
+  clipOrder.sort((a, b) => clipEdge[a] - clipEdge[b]);
+  let started = 0;
+  for (let rank = 0; rank < clipOrder.length; rank++) {
+    const clip = clipOrder[rank];
+    const v = videos[clip];
+    if (rank < MAX_DECODING && clipEdge[clip] < CULL_EDGE) {
+      clipIdle[clip] = 0;
+      // Nearest clips are first in the ranking, so the stagger always
+      // spends its budget on the panels closest to the middle of frame.
+      if (v.paused && started < RESUME_PER_TICK) {
+        started++;
+        v.play().catch(() => {});
+      }
+      continue;
+    }
+    clipIdle[clip] += elapsed;
+    if (clipIdle[clip] >= CULL_HOLD_S && !v.paused) v.pause();
+  }
+}
diff --git a/frontend/apps/artcraft-website-next/src/components/landing/hero-wordmark.tsx b/frontend/apps/artcraft-website-next/src/components/landing/hero-wordmark.tsx
index d5b3c66d07..7d948cc455 100644
--- a/frontend/apps/artcraft-website-next/src/components/landing/hero-wordmark.tsx
+++ b/frontend/apps/artcraft-website-next/src/components/landing/hero-wordmark.tsx
@@ -4,8 +4,13 @@ import { Component, useEffect, useRef, useState, type ReactNode } from "react";
 import { Canvas, useThree } from "@react-three/fiber";
 import * as THREE from "three";
 import { watchThemeColors, type ThemeColors } from "@/lib/theme-colors";
+import { heroWordmark } from "@/components/ruler/ruler-shared";
 import HeroWall, { createWallDrag } from "./hero-wall";
 
+const WORDMARK_TEXT = "ARTCRAFT";
+const WORDMARK_FONT =
+  "var(--font-archivo-black), var(--font-archivo), system-ui, sans-serif";
+
 type PointerState = {
   x: number;
   y: number;
@@ -26,6 +31,7 @@ export default function HeroWordmark() {
   const containerRef = useRef<HTMLDivElement>(null);
   const pointerRef = useRef<PointerState>({ x: 0, y: 0, active: false });
   const wallDragRef = useRef(createWallDrag());
+  const [onScreen, setOnScreen] = useState(true);
 
   // Gate: motion allowed and the tab actually foregrounded (a canvas born in
   // a hidden tab can come up blank).
@@ -102,6 +108,33 @@ export default function HeroWordmark() {
     };
   }, []);
 
+  // The hero sits at the top of a long page. Once it scrolls away there is
+  // nothing to look at, so stop the render loop and let the wall park its
+  // video decoders. Same when the tab goes to the background, which the
+  // observer alone would not catch.
+  useEffect(() => {
+    const container = containerRef.current;
+    if (!container) return;
+    let intersecting = true;
+    const sync = () => setOnScreen(intersecting && !document.hidden);
+    const observer = new IntersectionObserver(
+      ([entry]) => {
+        intersecting = entry.isIntersecting;
+        sync();
+      },
+      // Generous margin: the wall refills its decoders a few at a time, so
+      // it needs a head start to be at full speed by the time a scroll back
+      // up actually brings it into view.
+      { rootMargin: "600px 0px" },
+    );
+    observer.observe(container);
+    document.addEventListener("visibilitychange", sync);
+    return () => {
+      observer.disconnect();
+      document.removeEventListener("visibilitychange", sync);
+    };
+  }, []);
+
   const active = ready && colors !== null;
 
   return (
@@ -114,7 +147,11 @@ export default function HeroWordmark() {
           <Canvas
             aria-hidden
             tabIndex={-1}
-            dpr={[1, 2]}
+            // Video panels gain nothing from a 2x framebuffer; the hairline
+            // frames are the only detail that wants the extra samples, and
+            // 1.5x plus MSAA keeps them clean for a lot less fill.
+            dpr={[1, 1.5]}
+            frameloop={onScreen ? "always" : "never"}
             gl={{
               antialias: true,
               alpha: true,
@@ -123,45 +160,24 @@ export default function HeroWordmark() {
             style={{ position: "absolute", inset: 0, pointerEvents: "none" }}
           >
             <FittedCamera />
-            <HeroWall pointer={pointerRef} drag={wallDragRef} colors={colors} />
+            <HeroWall
+              pointer={pointerRef}
+              drag={wallDragRef}
+              colors={colors}
+              onScreen={onScreen}
+            />
           </Canvas>
         </CanvasBoundary>
       )}
 
       {/* The wordmark, justified flush to the hero width (the big-type
-          poster treatment): SVG text with textLength stretches the word
-          edge-to-edge at any viewport, so the height rides the width via
-          the viewBox aspect. Still real selectable/crawlable text. The
-          soft drop-shadow is a legibility halo lifting the type off the
-          busy footage, not decoration (vw units so it scales with the
-          word). */}
-      <div className="pointer-events-none absolute inset-0 z-10 flex items-center justify-center px-4 text-ink-strong md:px-6">
-        <svg
-          className="w-[62%]"
-          viewBox="0 0 720 74"
-          style={{
-            overflow: "visible",
-            filter:
-              "drop-shadow(0 0 0.3vw color-mix(in srgb, var(--bg) 60%, transparent)) drop-shadow(0 0.2vw 1.2vw color-mix(in srgb, var(--bg) 45%, transparent))",
-          }}
-        >
-          <text
-            x="360"
-            y="72"
-            textAnchor="middle"
-            textLength="780"
-            lengthAdjust="spacingAndGlyphs"
-            fill="currentColor"
-            style={{
-              fontFamily:
-                "var(--font-archivo-black), var(--font-archivo), system-ui, sans-serif",
-              fontSize: "100px",
-            }}
-          >
-            ARTCRAFT
-          </text>
-        </svg>
-      </div>
+          poster treatment) — per-letter spans instead of SVG text, because
+          these very spans ARE the ruler's hero heading: the scroll ruler's
+          HeadingFlow drives their transforms so the resting title peels
+          tail-first onto the rail as the visitor scrolls out of the
+          landing. Crawlable via role="img" + aria-label; z-40 so letters
+          in transit ride above later sections (below the z-50 nav). */}
+      <MorphWordmark />
 
       {active && (
         <div
@@ -176,6 +192,129 @@ export default function HeroWordmark() {
   );
 }
 
+// The justified wordmark letters. Font size is derived so the word's
+// natural advance run spans the 62% column exactly (the spacingAndGlyphs
+// stretch of the old SVG, minus the SVG). After layout, each letter's
+// natural center and advance are measured and published to the shared
+// heroWordmark channel for the ruler to drive; transforms are reset before
+// measuring so a mid-morph resize re-baselines cleanly.
+function MorphWordmark() {
+  const boxRef = useRef<HTMLDivElement>(null);
+  const letterRefs = useRef<(HTMLSpanElement | null)[]>([]);
+  const [fontPx, setFontPx] = useState(0);
+
+  useEffect(() => {
+    const box = boxRef.current;
+    if (!box) return;
+    let cancelled = false;
+
+    const compute = () => {
+      if (cancelled) return;
+      const probe = document.createElement("span");
+      probe.style.cssText =
+        "position:absolute;left:-9999px;top:0;visibility:hidden;white-space:pre;font-size:100px;line-height:1;";
+      probe.style.fontFamily = WORDMARK_FONT;
+      probe.textContent = WORDMARK_TEXT;
+      document.body.appendChild(probe);
+      const w100 = probe.getBoundingClientRect().width;
+      probe.remove();
+      const target = box.clientWidth;
+      if (w100 > 0 && target > 0) {
+        setFontPx(Math.round((target / w100) * 1000) / 10);
+      }
+    };
+
+    const ready = document.fonts?.ready;
+    if (ready) ready.then(compute).catch(compute);
+    else compute();
+    const ro = new ResizeObserver(compute);
+    ro.observe(box);
+    return () => {
+      cancelled = true;
+      ro.disconnect();
+    };
+  }, []);
+
+  // Publish letter geometry once the real size is applied.
+  useEffect(() => {
+    if (!fontPx) return;
+    const els = letterRefs.current.filter(
+      (el): el is HTMLSpanElement => !!el,
+    );
+    if (els.length !== WORDMARK_TEXT.length) return;
+
+    const measure = () => {
+      for (const el of els) el.style.transform = "";
+      const rects = els.map((el) => el.getBoundingClientRect());
+      heroWordmark.els = els;
+      heroWordmark.baseX = rects.map((r) => r.left + r.width / 2);
+      heroWordmark.baseDocY = rects.map(
+        (r) => r.top + r.height / 2 + window.scrollY,
+      );
+      const adv = rects.map((r) => r.width / fontPx);
+      const cum: number[] = [];
+      let total = 0;
+      for (const a of adv) {
+        cum.push(total);
+        total += a;
+      }
+      heroWordmark.metrics = { adv, cum, total };
+      heroWordmark.fontPx = fontPx;
+      heroWordmark.ready = true;
+    };
+
+    measure();
+    window.addEventListener("resize", measure);
+    return () => {
+      window.removeEventListener("resize", measure);
+      heroWordmark.ready = false;
+      heroWordmark.els = [];
+    };
+  }, [fontPx]);
+
+  return (
+    <div className="pointer-events-none absolute inset-0 z-40 flex items-center justify-center px-4 md:px-6">
+      <div ref={boxRef} className="w-[62%]">
+        <div
+          role="img"
+          aria-label={WORDMARK_TEXT}
+          className="whitespace-pre text-ink-strong"
+          style={{
+            fontFamily: WORDMARK_FONT,
+            fontSize: fontPx || "10.5vw",
+            lineHeight: 1,
+          }}
+        >
+          {WORDMARK_TEXT.split("").map((ch, i) => (
+            <span
+              key={i}
+              aria-hidden
+              ref={(el) => {
+                letterRefs.current[i] = el;
+              }}
+              className="inline-block"
+              style={{
+                willChange: "transform, opacity",
+                // Three stacked halos in the page background color: a tight
+                // contact edge, a mid falloff, and a wide pool that sinks
+                // the busiest footage behind the letters. Sized in vw so the
+                // spread tracks the type as the wordmark scales.
+                textShadow: [
+                  "0 0 0.6vw color-mix(in srgb, var(--bg) 92%, transparent)",
+                  "0 0.25vw 2.4vw color-mix(in srgb, var(--bg) 78%, transparent)",
+                  "0 0.4vw 5vw color-mix(in srgb, var(--bg) 55%, transparent)",
+                ].join(", "),
+              }}
+            >
+              {ch}
+            </span>
+          ))}
+        </div>
+      </div>
+    </div>
+  );
+}
+
 // Perspective camera fitted so 1 world unit == 1 CSS pixel on the z=0 plane:
 // wall layout and pointer coordinates all agree. FOV must match hero-wall's
 // vignette projection.
diff --git a/frontend/apps/artcraft-website-next/src/components/landing/hero.tsx b/frontend/apps/artcraft-website-next/src/components/landing/hero.tsx
index e4d8c930eb..ffffe35de9 100644
--- a/frontend/apps/artcraft-website-next/src/components/landing/hero.tsx
+++ b/frontend/apps/artcraft-website-next/src/components/landing/hero.tsx
@@ -8,7 +8,7 @@ import HeroViewport from "./hero-viewport";
 
 export default function Hero() {
   return (
-    <section className="relative">
+    <section id="hero" className="relative">
       {/* Full-bleed hero — crisp display-type wordmark over the render
           wall: rows of Seedance takes forming one perspective wall that
           drifts behind the word and answers the cursor. */}
diff --git a/frontend/apps/artcraft-website-next/src/components/motion-provider.tsx b/frontend/apps/artcraft-website-next/src/components/motion-provider.tsx
index fc503a25d4..f52a7f7e82 100644
--- a/frontend/apps/artcraft-website-next/src/components/motion-provider.tsx
+++ b/frontend/apps/artcraft-website-next/src/components/motion-provider.tsx
@@ -4,6 +4,7 @@ import { useEffect } from "react";
 import Lenis from "lenis";
 import gsap from "gsap";
 import { ScrollTrigger } from "gsap/ScrollTrigger";
+import { lenisRef } from "@/lib/lenis-ref";
 
 gsap.registerPlugin(ScrollTrigger);
 
@@ -26,6 +27,7 @@ export default function MotionProvider({
       lerp: 0.12,
       anchors: true,
     });
+    lenisRef.current = lenis;
 
     lenis.on("scroll", ScrollTrigger.update);
     const tick = (time: number) => lenis.raf(time * 1000);
@@ -34,6 +36,7 @@ export default function MotionProvider({
 
     return () => {
       gsap.ticker.remove(tick);
+      lenisRef.current = null;
       lenis.destroy();
     };
   }, []);
diff --git a/frontend/apps/artcraft-website-next/src/components/ruler/heading-flow.tsx b/frontend/apps/artcraft-website-next/src/components/ruler/heading-flow.tsx
new file mode 100644
index 0000000000..03fbd0a93d
--- /dev/null
+++ b/frontend/apps/artcraft-website-next/src/components/ruler/heading-flow.tsx
@@ -0,0 +1,626 @@
+"use client";
+
+import { Fragment, useEffect, useMemo, useRef, useState } from "react";
+import gsap from "gsap";
+import { lenisRef } from "@/lib/lenis-ref";
+import {
+  NAV_H,
+  clamp01,
+  easeInOutCubic,
+  easeOutExpo,
+  heroWordmark,
+  railOccupancy,
+  rulerMap,
+  rulerZoom,
+  type MeasuredSection,
+  type RulerMode,
+  type RulerSide,
+} from "./ruler-shared";
+import {
+  rulerLayoutTuner,
+  rulerLookTuner,
+  rulerMotionTuner,
+} from "./ruler-tunables";
+
+// The ruler's heading lifecycle. Each section's heading is a word with
+// three homes, all in the ruler gutter:
+//
+//   queued  — compact horizontal link stacked at the bottom (the navbar:
+//             where you're going),
+//   riding  — vertical (reading upward) on the tick rail, 1:1 with the
+//             document, annotating its section as it scrolls,
+//   stacked — horizontal at the top (where you've been): passed sections
+//             pin under the nav as a compact pile mirroring the bottom
+//             queue, and the current section's heading sits just below the
+//             pile at full size. When the next word flips in, the current
+//             one demotes up into the pile — the two edges read as one
+//             symmetric sectional navbar.
+//
+// Transitions between homes are scrub-bound letter-by-letter curves. Every
+// word's pose is a pure function of scroll position, so everything is
+// reversible; when scroll rests with a top flip half-done, a damped snap
+// resolves it to the nearest side.
+//
+// The hero is special: it IS the current section from load, so its whole
+// lifecycle is one flip — the wordmark's own letter spans (published via
+// the shared heroWordmark channel) fly STRAIGHT from the resting title to
+// the top current-heading slot as the wordmark is about to duck under the
+// nav (title-condenses-into-header), no queue home and no rail ride. From
+// the stack onward it behaves like any section (demotes when FEATURES
+// flips in). The hero letters keep their Archivo Black wordmark face
+// through the whole lifecycle — brand identity, and font families can't
+// interpolate.
+
+// A letter's pose on screen. x/y are the letter center in viewport px.
+type Pose = {
+  x: number;
+  y: number;
+  rot: number;
+  scale: number;
+  alpha: number;
+};
+
+// Per-label advance metrics, normalized to a 1px font so any size is a
+// multiply. cum[i] is the advance before letter i; total is the word width.
+type WordMetrics = {
+  adv: number[];
+  cum: number[];
+  total: number;
+};
+
+type WordRefs = {
+  letters: (HTMLSpanElement | null)[];
+  hit: HTMLAnchorElement | null;
+};
+
+export default function HeadingFlow({
+  mode,
+  side,
+  sections,
+  geom,
+  layoutVersion,
+}: {
+  mode: RulerMode;
+  side: RulerSide;
+  sections: MeasuredSection[];
+  geom: { docH: number; vh: number; vw: number };
+  layoutVersion: number;
+}) {
+  const [metrics, setMetrics] = useState<Record<string, WordMetrics> | null>(
+    null,
+  );
+  const wordRefs = useRef<WordRefs[]>([]);
+  const fs = useRef({
+    lastY: 0,
+    vel: 0,
+    snapSince: null as number | null,
+    snapping: false,
+  });
+
+  const layout = useMemo(
+    () => rulerLayoutTuner.read(),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [layoutVersion],
+  );
+
+  const labelsKey = sections.map((s) => s.label).join("|");
+
+  // Letter advances need the real display face — measure after fonts load.
+  useEffect(() => {
+    if (mode !== "full" || !sections.length) return;
+    let cancelled = false;
+    const run = () => {
+      if (cancelled) return;
+      setMetrics(measureLabels(sections.map((s) => s.label)));
+    };
+    const ready = document.fonts?.ready;
+    if (ready) ready.then(run).catch(run);
+    else run();
+    return () => {
+      cancelled = true;
+    };
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+  }, [mode, labelsKey]);
+
+  // Frame loop: pose every letter from the current scroll position.
+  useEffect(() => {
+    if (mode !== "full" || !metrics || !sections.length || !geom.docH) return;
+
+    const tick = (_time: number, deltaMs: number) => {
+      const st = fs.current;
+      const lay = rulerLayoutTuner.read();
+      const mt = rulerMotionTuner.read();
+      const lk = rulerLookTuner.read();
+      const { docH, vh, vw } = geom;
+      const dt = Math.min(deltaMs / 1000, 0.1) || 0.016;
+
+      const scrollY = window.scrollY;
+      const maxScroll = Math.max(1, docH - vh);
+      const progress = clamp01(scrollY / maxScroll);
+      const map = rulerMap(vh, lay.edgePad);
+      const drift = map.drift(progress);
+
+      const raw = (scrollY - st.lastY) / dt;
+      st.lastY = scrollY;
+      st.vel += (raw - st.vel) * (1 - Math.exp(-6 * dt));
+
+      const T = (lay.thresholdPct / 100) * vh;
+      const yTopLine = NAV_H + lay.topPad;
+      const yQueueLine = vh - lay.queuePad;
+      const hp = lay.headingPx;
+      const rs = lay.ridingPx / hp;
+      const qs = lay.queuePx / hp;
+      const inwardSign = side === "right" ? -1 : 1;
+      const railCenterX =
+        side === "right" ? vw - lay.railW / 2 : lay.railW / 2;
+      // Zoomed map blend: every word converges on a horizontal label at
+      // its section's true percent position while the rail compresses.
+      const zoomE = easeInOutCubic(rulerZoom.p);
+
+      // Phase pass: flip/detach progress per word. Anchors increase with
+      // index, so stacked words are always a prefix and at most one word is
+      // mid-flip at a time.
+      const phases = sections.map((s) => {
+        const m =
+          s.isHero && heroWordmark.ready
+            ? heroWordmark.metrics
+            : metrics[s.label];
+        const rideLen = (m?.total ?? 0) * hp * rs;
+        const v = s.anchor - scrollY + drift;
+        let flipP: number;
+        let detachP = 0;
+        // Some flips run in scroll space instead of anchor space; snap
+        // resolves those against these bounds.
+        let scrollFlip: { start: number; end: number } | null = null;
+        if (s.isHero) {
+          // The hero IS the current section from load — its heading goes
+          // STRAIGHT to the top slot (no queue, no ride): the whole
+          // lifecycle is one flip, driven by the wordmark about to duck
+          // under the nav (title-condenses-into-header), begun heroLead px
+          // early and spanning heroZone px of scroll.
+          detachP = 1;
+          const wordTop = heroWordmark.ready
+            ? Math.min(...heroWordmark.baseDocY) - heroWordmark.fontPx * 0.5
+            : 0;
+          const start = Math.max(0, wordTop - NAV_H - mt.heroLead);
+          const zone = Math.max(1, mt.heroZone);
+          flipP = clamp01((scrollY - start) / zone);
+          scrollFlip = { start, end: start + zone };
+        } else {
+          flipP = clamp01((T + mt.flipZone - v) / mt.flipZone);
+          // End-of-page driver: a section too short to ever carry its
+          // word up to the threshold (its best reachable v is still below
+          // the flip line) flips from "section fully in view" to "no more
+          // scroll". At page bottom the pile is complete.
+          if (s.anchor - maxScroll > T) {
+            const endStart = Math.min(s.bottom - vh, maxScroll - 24);
+            const zone = Math.max(24, maxScroll - endStart);
+            flipP = Math.max(flipP, clamp01((scrollY - endStart) / zone));
+            scrollFlip = { start: endStart, end: maxScroll };
+          }
+        }
+        return { v, rideLen, flipP, scrollFlip, detachP, yq: yQueueLine };
+      });
+
+      // Backward pass: a word's queue slot depends on the occupancy of the
+      // words below it, and its detach completes when its riding column's
+      // BOTTOM reaches that very slot — the whole column ends up above the
+      // queue line, fully on-screen, and the tail-led letters sweep upward
+      // in the ease-out arc. (Chosen deliberately over tail-at-the-line
+      // variants: those either hung letters past the viewport or pinned
+      // the word at the line until the morph finished.) yq is stable
+      // during the word's own morph because later words detach much later.
+      {
+        let below = 0;
+        for (let wi = sections.length - 1; wi >= 0; wi--) {
+          if (sections[wi].isHero) continue; // no queue home, detachP = 1
+          const ph = phases[wi];
+          ph.yq = yQueueLine - lay.queueSlot * below;
+          ph.detachP = clamp01(
+            (ph.yq + mt.detachZone - (ph.v + ph.rideLen)) / mt.detachZone,
+          );
+          below += 1 - ph.detachP;
+        }
+      }
+
+      railOccupancy.spans.length = 0;
+
+      let stackedCount = 0;
+      let flipShift = 0;
+      for (const p of phases) {
+        if (p.flipP >= 1) stackedCount++;
+        else if (p.flipP > 0) flipShift += p.flipP;
+      }
+
+      // Horizontal home for a word: letters run inward from the rail, with
+      // the reading direction arranged so the word's tail sits nearest the
+      // rail on a right-side ruler (and its head nearest on the left).
+      const horizPose = (
+        m: WordMetrics,
+        i: number,
+        yLine: number,
+        s: number,
+        alpha: number,
+      ): Pose => {
+        const along = (m.cum[i] + m.adv[i] / 2) * hp * s;
+        const inward =
+          lay.railW +
+          lay.textPad +
+          (side === "right" ? m.total * hp * s - along : along);
+        return {
+          x: side === "right" ? vw - inward : inward,
+          y: yLine,
+          rot: 0,
+          scale: s,
+          alpha,
+        };
+      };
+
+      // Vertical column with its top at `top`. In transit it shares the
+      // queue links' alpha — only the top heading is active-bright; the
+      // flip lerps toward the stack pose, so a word brightens on arrival.
+      const ridePose = (m: WordMetrics, i: number, top: number): Pose => ({
+        x: railCenterX,
+        y: top + (m.total - m.cum[i] - m.adv[i] / 2) * hp * rs,
+        rot: -90,
+        scale: rs,
+        alpha: lk.queueAlpha,
+      });
+
+      for (let wi = 0; wi < sections.length; wi++) {
+        const s = sections[wi];
+        const heroDrive = s.isHero && heroWordmark.ready;
+        const m = heroDrive ? heroWordmark.metrics : metrics[s.label];
+        const refs = wordRefs.current[wi];
+        if (!m || !refs || (s.isHero && !heroDrive)) continue;
+        const { v, rideLen, flipP, detachP, yq } = phases[wi];
+        const n = m.adv.length;
+
+        // The hero's flip "from" home is the wordmark's own resting
+        // layout — identity transform at rest, so it's pixel-perfect and
+        // crisp, and the title flies STRAIGHT to the top heading slot.
+        const heroBase = (i: number): Pose => ({
+          x: heroWordmark.baseX[i],
+          y: heroWordmark.baseDocY[i] - scrollY,
+          rot: 0,
+          scale: heroWordmark.fontPx / hp,
+          alpha: 1,
+        });
+
+        // Word-level from/to homes for the active transition.
+        let p: number;
+        let from: (i: number) => Pose;
+        let to: (i: number) => Pose;
+        let reverseStagger = false;
+        if (flipP > 0) {
+          p = flipP;
+          // Tail-first here too: the tail letter sits at the column's top
+          // (or, for the hero, nearest the rail) and lands nearest the
+          // rail — shortest flight leads the peel.
+          reverseStagger = true;
+          from = heroDrive ? heroBase : (i) => ridePose(m, i, v);
+          // Stacked words keep their document-order slot in the top pile
+          // (wi is the index from the top, since stacked words are always
+          // a prefix). The newest fully-stacked word holds the "current"
+          // pose — full size, offset below the pile — and demotes into a
+          // compact pile entry as the next word flips in.
+          if (flipP >= 1) {
+            const demote = wi === stackedCount - 1 ? flipShift : 1;
+            const y =
+              yTopLine + wi * lay.queueSlot + lay.currentGap * (1 - demote);
+            const scale = 1 - (1 - qs) * demote;
+            const alpha = 1 - (1 - lk.queueAlpha) * demote;
+            to = (i) => horizPose(m, i, y, scale, alpha);
+          } else {
+            to = (i) =>
+              horizPose(
+                m,
+                i,
+                yTopLine + wi * lay.queueSlot + lay.currentGap,
+                1,
+                1,
+              );
+          }
+        } else if (detachP < 1) {
+          p = detachP;
+          // Mirrored stagger: the rail-adjacent tail letter peels first, so
+          // letters lift off in sequence from the rail side instead of the
+          // lead letter sweeping across the ones still resting in the queue.
+          reverseStagger = true;
+          // The morph target is STATIONARY: the riding pose the word holds
+          // the instant detach completes — full column resting just above
+          // its queue slot (bottom at the line). Letters sweep up in the
+          // ease-out arc, fully on-screen; at p=1 this equals the true
+          // riding pose, which takes over seamlessly.
+          const vForm = yq - rideLen;
+          to = (i) => ridePose(m, i, vForm);
+          from = (i) => horizPose(m, i, yq, qs, lk.queueAlpha);
+        } else {
+          p = 1;
+          from = to = heroDrive ? heroBase : (i) => ridePose(m, i, v);
+        }
+
+        // Letter pass: staggered eased progress along an inward-bowed
+        // quadratic curve between the two homes.
+        const sf = mt.stagger;
+        const span = 1 + (n - 1) * sf;
+        const mapY = map.base + ((s.isHero ? 0 : s.anchor) / docH) * map.span;
+        // Hero letters are the wordmark's own spans (base-relative
+        // transforms, rendered at fontPx so scale writes need the hp/fontPx
+        // correction). Its zoom-map blend scales with detachP so hovering
+        // the rail at page top never dismantles the resting wordmark.
+        const letterEls = heroDrive ? heroWordmark.els : refs.letters;
+        const scaleFix = heroDrive ? hp / heroWordmark.fontPx : 1;
+        const wz = heroDrive ? zoomE * Math.min(1, flipP) : zoomE;
+        let minX = Infinity;
+        let maxX = -Infinity;
+        let minY = Infinity;
+        let maxY = -Infinity;
+        let maxAlpha = 0;
+        for (let i = 0; i < n; i++) {
+          const el = letterEls[i];
+          if (!el) continue;
+          const si = reverseStagger ? n - 1 - i : i;
+          const pi = clamp01(p * span - si * sf);
+          const e = easeInOutCubic(pi);
+          const a = from(i);
+          const b = to(i);
+          const cx = (a.x + b.x) / 2 + inwardSign * mt.arc;
+          const cy = (a.y + b.y) / 2;
+          const u = 1 - e;
+          let x = u * u * a.x + 2 * u * e * cx + e * e * b.x;
+          let y = u * u * a.y + 2 * u * e * cy + e * e * b.y;
+          let rot = a.rot + (b.rot - a.rot) * e;
+          let scale = a.scale + (b.scale - a.scale) * e;
+          let alpha = a.alpha + (b.alpha - a.alpha) * e;
+          if (wz > 0) {
+            const mp = horizPose(m, i, mapY, qs, lk.mapAlpha);
+            x += (mp.x - x) * wz;
+            y += (mp.y - y) * wz;
+            rot *= 1 - wz;
+            scale += (mp.scale - scale) * wz;
+            alpha += (mp.alpha - alpha) * wz;
+          }
+          if (heroDrive) {
+            el.style.transform = `translate3d(${
+              x - heroWordmark.baseX[i]
+            }px, ${
+              y - (heroWordmark.baseDocY[i] - scrollY)
+            }px, 0) rotate(${rot}deg) scale(${scale * scaleFix})`;
+          } else {
+            el.style.transform = `translate3d(${x}px, ${y}px, 0) translate(-50%, -50%) rotate(${rot}deg) scale(${scale})`;
+          }
+          el.style.opacity = String(alpha);
+          if (alpha > maxAlpha) maxAlpha = alpha;
+          // Per-axis extents (swapped when the glyph is rotated toward
+          // vertical) so hit boxes stay tight: a shared radius made
+          // neighboring queue links overlap, and the topmost sibling ate
+          // clicks meant for the one above it.
+          const wHalf = (m.adv[i] * hp * scale) / 2 + 2;
+          const hHalf = (hp * scale) / 2 + 2;
+          const vertical = Math.abs(rot) > 45;
+          const xHalf = vertical ? hHalf : wHalf;
+          const yHalf = vertical ? wHalf : hHalf;
+          if (x - xHalf < minX) minX = x - xHalf;
+          if (x + xHalf > maxX) maxX = x + xHalf;
+          if (y - yHalf < minY) minY = y - yHalf;
+          if (y + yHalf > maxY) maxY = y + yHalf;
+        }
+
+        // Publish the word's riding footprint — the settled column span,
+        // NOT the in-flight letter bbox (that swept across labels during
+        // detach/flip flights and made them flicker) — with a strength
+        // that ramps smoothly with how on-rail the word is, so labels fade
+        // in proportion instead of blinking.
+        // (The hero never rides the rail — it flies straight to the top —
+        // so it never occupies the tick lane.)
+        const onRail = s.isHero ? 0 : detachP * (1 - flipP);
+        if (onRail > 0.02) {
+          railOccupancy.spans.push({ top: v, bottom: v + rideLen, k: onRail });
+        }
+
+        // Hit box hugs the word wherever it is; a fully invisible word
+        // (the hero before its entrance) must not capture clicks.
+        if (refs.hit && isFinite(minX)) {
+          refs.hit.style.left = `${minX - 2}px`;
+          refs.hit.style.top = `${minY - 2}px`;
+          refs.hit.style.width = `${maxX - minX + 4}px`;
+          refs.hit.style.height = `${maxY - minY + 4}px`;
+          // The resting hero wordmark must stay click-transparent (the
+          // wall's drag lives underneath it) — its link only arms once the
+          // morph is underway.
+          refs.hit.style.pointerEvents =
+            maxAlpha > 0.05 && (!s.isHero || flipP > 0.05)
+              ? "auto"
+              : "none";
+        }
+
+      }
+
+      // Snap: scroll resting with a top flip half-done resolves to the
+      // nearest side after a beat, damped through Lenis.
+      const lenis = lenisRef.current;
+      const now = performance.now();
+      const midIdx = phases.findIndex(
+        (ph) => ph.flipP > 0.04 && ph.flipP < 0.96,
+      );
+      if (st.snapping) {
+        if (midIdx < 0) st.snapping = false;
+      } else if (
+        midIdx >= 0 &&
+        Math.abs(st.vel) < 30 &&
+        lenis &&
+        !rulerZoom.dragging &&
+        rulerZoom.p < 0.3
+      ) {
+        if (st.snapSince === null) {
+          st.snapSince = now;
+        } else if (now - st.snapSince > mt.snapDelay) {
+          const ph = phases[midIdx];
+          const sMid = sections[midIdx];
+          // Scroll-space flips (the hero's straight-to-header morph, and
+          // end-of-page flips whose v never reaches the threshold) resolve
+          // against their own bounds; threshold flips resolve in v space.
+          let raw: number;
+          if (ph.scrollFlip) {
+            raw =
+              ph.flipP >= 0.5 ? ph.scrollFlip.end + 4 : ph.scrollFlip.start - 4;
+          } else {
+            const vTarget = ph.flipP >= 0.5 ? T - 4 : T + mt.flipZone + 4;
+            raw = sMid.anchor + drift - vTarget;
+          }
+          const target = Math.max(0, Math.min(maxScroll, raw));
+          st.snapping = true;
+          st.snapSince = null;
+          lenis.scrollTo(target, {
+            duration: mt.snapDur,
+            easing: easeInOutCubic,
+            onComplete: () => {
+              st.snapping = false;
+            },
+          });
+        }
+      } else {
+        st.snapSince = null;
+      }
+    };
+
+    gsap.ticker.add(tick);
+    return () => {
+      gsap.ticker.remove(tick);
+    };
+  }, [mode, metrics, sections, geom, side, layoutVersion]);
+
+  if (!sections.length) return null;
+
+  // Reduced motion: the headings become a plain fixed section index by the
+  // rail's bottom — same destinations, no choreography.
+  if (mode === "static") {
+    const sideStyle =
+      side === "right"
+        ? { right: layout.railW + layout.textPad, textAlign: "right" as const }
+        : { left: layout.railW + layout.textPad };
+    return (
+      <nav
+        aria-label="Sections"
+        className="fixed z-40"
+        style={{ bottom: layout.queuePad, ...sideStyle }}
+      >
+        <ul className="flex flex-col gap-1.5">
+          {sections.map((s) => (
+            <li key={s.id}>
+              <a
+                href={`#${s.id}`}
+                className="font-display text-ink hover:text-ink-strong"
+                style={{ fontSize: layout.queuePx + 2 }}
+              >
+                {s.label}
+              </a>
+            </li>
+          ))}
+        </ul>
+      </nav>
+    );
+  }
+
+  if (!metrics) return null;
+
+  const jump = (s: MeasuredSection) => (e: React.MouseEvent) => {
+    e.preventDefault();
+    e.stopPropagation();
+    const lenis = lenisRef.current;
+    const el = document.getElementById(s.id);
+    const target = s.isHero
+      ? 0
+      : el
+        ? el.getBoundingClientRect().top + window.scrollY - NAV_H
+        : s.anchor - NAV_H;
+    if (lenis) {
+      lenis.scrollTo(target, {
+        duration: rulerMotionTuner.read().jumpDur,
+        easing: easeOutExpo,
+      });
+    } else {
+      window.scrollTo({ top: target });
+    }
+  };
+
+  return (
+    <div className="pointer-events-none fixed inset-0 z-40">
+      {sections.map((s, wi) => {
+        const refs = (wordRefs.current[wi] ??= {
+          letters: [],
+          hit: null,
+        });
+        return (
+          <Fragment key={s.id}>
+            <a
+              href={`#${s.id}`}
+              ref={(el) => {
+                refs.hit = el;
+              }}
+              onClick={jump(s)}
+              aria-label={`Jump to ${s.label}`}
+              className="pointer-events-auto absolute cursor-pointer"
+            />
+            {/* Hero letters live in the hero wordmark itself and are
+                driven via the shared channel — render none here. */}
+            {!s.isHero &&
+              s.label.split("").map((ch, li) => (
+              <span
+                key={li}
+                ref={(el) => {
+                  refs.letters[li] = el;
+                }}
+                aria-hidden
+                className="font-display absolute top-0 left-0 whitespace-pre text-ink-strong"
+                style={{
+                  fontSize: layout.headingPx,
+                  lineHeight: 1,
+                  opacity: 0,
+                  willChange: "transform, opacity",
+                  textShadow: "0 0 4px var(--bg), 0 0 10px var(--bg)",
+                }}
+              >
+                {ch}
+              </span>
+            ))}
+          </Fragment>
+        );
+      })}
+    </div>
+  );
+}
+
+// Measures per-letter advances for each label by laying the letters out as
+// spans in a hidden probe styled like the real headings. Normalized to a
+// 1px font (measured at 100px for integer-rounding headroom).
+function measureLabels(labels: string[]): Record<string, WordMetrics> {
+  const probe = document.createElement("div");
+  probe.className = "font-display";
+  probe.style.cssText =
+    "position:absolute;left:-9999px;top:0;visibility:hidden;white-space:pre;font-size:100px;line-height:1;";
+  document.body.appendChild(probe);
+
+  const out: Record<string, WordMetrics> = {};
+  for (const label of labels) {
+    probe.textContent = "";
+    const spans = label.split("").map((ch) => {
+      const span = document.createElement("span");
+      span.textContent = ch;
+      probe.appendChild(span);
+      return span;
+    });
+    const adv = spans.map((sp) => sp.getBoundingClientRect().width / 100);
+    const cum: number[] = [];
+    let total = 0;
+    for (const a of adv) {
+      cum.push(total);
+      total += a;
+    }
+    out[label] = { adv, cum, total };
+  }
+
+  probe.remove();
+  return out;
+}
diff --git a/frontend/apps/artcraft-website-next/src/components/ruler/ruler-shared.ts b/frontend/apps/artcraft-website-next/src/components/ruler/ruler-shared.ts
new file mode 100644
index 0000000000..0a75759d74
--- /dev/null
+++ b/frontend/apps/artcraft-website-next/src/components/ruler/ruler-shared.ts
@@ -0,0 +1,92 @@
+// Shared bits for the scroll ruler instrument (see scroll-ruler.tsx for the
+// big picture).
+
+/** Height of the sticky SiteNav (h-12). The rail hides under it; the needle's
+ * travel and the click→progress mapping run over [NAV_H, viewport bottom]. */
+export const NAV_H = 48;
+
+/** "full" = the whole instrument, native scrollbar hidden. "static" = the
+ * reduced-motion rail: ticks + needle + plain section links, native
+ * scrollbar kept. Coarse pointers and small screens get no ruler at all. */
+export type RulerMode = "full" | "static";
+
+export type RulerSide = "left" | "right";
+
+/** A ruler section resolved against the live DOM. `anchor` is the document Y
+ * the section's word rides at (the section top — except the hero, whose
+ * anchor hangs `heroOffset` above the hero's bottom so the wordmark handoff
+ * happens as the visitor leaves the landing area). `bottom` is the document
+ * Y of the section's end, used to derive the end-of-page flip for sections
+ * too short to ever reach the threshold. */
+export type MeasuredSection = {
+  id: string;
+  label: string;
+  index: number;
+  anchor: number;
+  bottom: number;
+  isHero: boolean;
+};
+
+/** The zoom morph's shared per-frame state: ScrollRuler drives it (hover
+ * intent, drag, damped integration of `p`), HeadingFlow reads `p` to blend
+ * the heading lifecycle toward the compact map. 0 = 1:1 instrument,
+ * 1 = compressed full-page map. */
+export const rulerZoom = { target: 0, p: 0, dragging: false };
+
+/** The hero wordmark's live letter roster, published by HeroWordmark and
+ * driven per-frame by HeadingFlow: the SAME spans render the resting hero
+ * title (identity transform, crisp at full size) and then morph tail-first
+ * onto the rail as the visitor scrolls out of the landing — one element
+ * from hero to riding word to top stack. `baseX`/`baseDocY` are each
+ * letter's natural center (x viewport, y document); `metrics` are advances
+ * normalized per 1px of font, measured from the rendered letters. */
+export const heroWordmark: {
+  ready: boolean;
+  els: HTMLSpanElement[];
+  baseX: number[];
+  baseDocY: number[];
+  fontPx: number;
+  metrics: { adv: number[]; cum: number[]; total: number };
+} = {
+  ready: false,
+  els: [],
+  baseX: [],
+  baseDocY: [],
+  fontPx: 0,
+  metrics: { adv: [], cum: [], total: 0 },
+};
+
+/** Screen-space y-spans of the heading words' settled riding columns.
+ * HeadingFlow rewrites it every frame; the tick loop fades percent labels
+ * within a margin of any span (proximity yield — the scale gets out of a
+ * passing word's way). `k` ramps 0→1 with how on-rail the word is, so the
+ * yield eases in/out with the detach/flip transitions instead of blinking
+ * as letters fly past. */
+export const railOccupancy: {
+  spans: { top: number; bottom: number; k: number }[];
+} = {
+  spans: [],
+};
+
+/** The ruler's vertical mapping: progress/percent p ∈ [0,1] maps onto
+ * [NAV_H + pad, vh − pad] — in BOTH the 1:1 and compact states, so the
+ * needle-meets-its-tick invariant stays exact and the endpoint ticks
+ * (with their 0/100 labels) always rest fully inside the viewport.
+ * `drift(p)` is the track offset reconciling the 1:1 layout with the
+ * needle's travel; pad = 0 degenerates to the old NAV_H·(1−p). */
+export function rulerMap(vh: number, pad: number) {
+  const base = NAV_H + pad;
+  return {
+    base,
+    span: Math.max(1, vh - NAV_H - 2 * pad),
+    drift: (p: number) => base - p * (NAV_H + 2 * pad),
+  };
+}
+
+export const clamp01 = (x: number) => Math.max(0, Math.min(1, x));
+
+export const easeOutExpo = (t: number) =>
+  t >= 1 ? 1 : 1 - Math.pow(2, -10 * t);
+
+export const easeInOutCubic = (t: number) =>
+  t < 0.5 ? 4 * t * t * t : 1 - Math.pow(-2 * t + 2, 3) / 2;
diff --git a/frontend/apps/artcraft-website-next/src/components/ruler/ruler-tunables.ts b/frontend/apps/artcraft-website-next/src/components/ruler/ruler-tunables.ts
new file mode 100644
index 0000000000..ff89ad26d3
--- /dev/null
+++ b/frontend/apps/artcraft-website-next/src/components/ruler/ruler-tunables.ts
@@ -0,0 +1,358 @@
+import { defineTunables } from "@/lib/tuner";
+
+// Structure knobs — changing these rebuilds the tick track / word layouts
+// (consumers subscribe and debounce, same pattern as the hero wall).
+export const rulerLayoutTuner = defineTunables("rulerLayout", "Ruler layout", {
+  side: {
+    label: "Side 0=L 1=R",
+    min: 0,
+    max: 1,
+    step: 1,
+    default: 1,
+    info: "Which viewport edge the ruler lives on: 0 = left, 1 = right.",
+  },
+  edgePad: {
+    label: "Edge pad px",
+    min: 0,
+    max: 40,
+    step: 2,
+    default: 12,
+    info: "Vertical inset of the ruler's whole mapping (needle travel, clicks, compact map) from the nav bottom and viewport bottom — keeps the 0/100 ticks and labels fully visible.",
+  },
+  railW: {
+    label: "Rail width px",
+    min: 32,
+    max: 96,
+    step: 2,
+    default: 60,
+    info: "Width of the tick rail at the viewport edge; also the gutter reserved from page content.",
+  },
+  minorPct: {
+    label: "Tick every %",
+    min: 0.5,
+    max: 5,
+    step: 0.5,
+    default: 1,
+    info: "Scroll-percent spacing between minor ticks on the rail.",
+  },
+  labelPct: {
+    label: "Label every %",
+    min: 5,
+    max: 25,
+    step: 5,
+    default: 5,
+    info: "Scroll-percent spacing between the longer, number-labeled major ticks.",
+  },
+  thresholdPct: {
+    label: "Flip line vh%",
+    min: 4,
+    max: 40,
+    step: 1,
+    default: 12,
+    info: "Viewport-height % from the top where a riding word flips horizontal into the top stack.",
+  },
+  headingPx: {
+    label: "Heading px",
+    min: 12,
+    max: 34,
+    step: 1,
+    default: 34,
+    info: "Font size of the full-size current-section heading below the top pile.",
+  },
+  ridingPx: {
+    label: "Riding px",
+    min: 9,
+    max: 24,
+    step: 1,
+    default: 20,
+    info: "Font size of the vertical word riding the rail with its section.",
+  },
+  queuePx: {
+    label: "Queue px",
+    min: 9,
+    max: 24,
+    step: 1,
+    default: 16,
+    info: "Font size of the compact heading links (bottom queue and top pile).",
+  },
+  topPad: {
+    label: "Top pad px",
+    min: 4,
+    max: 120,
+    step: 4,
+    default: 28,
+    info: "Gap between the nav bar and the first heading in the top pile.",
+  },
+  currentGap: {
+    label: "Current gap px",
+    min: 8,
+    max: 80,
+    step: 2,
+    default: 26,
+    info: "Extra gap separating the full-size current heading from the compact pile above it.",
+  },
+  queueSlot: {
+    label: "Queue slot px",
+    min: 12,
+    max: 48,
+    step: 2,
+    default: 20,
+    info: "Vertical spacing between stacked heading links, top pile and bottom queue alike.",
+  },
+  queuePad: {
+    label: "Queue bottom px",
+    min: 8,
+    max: 120,
+    step: 4,
+    default: 36,
+    info: "Gap between the viewport bottom and the lowest queued heading.",
+  },
+  textPad: {
+    label: "Text pad px",
+    min: 0,
+    max: 48,
+    step: 2,
+    default: 0,
+    info: "Horizontal gap between the tick rail and the heading text.",
+  },
+});
+
+// Feel knobs — read per frame.
+export const rulerMotionTuner = defineTunables("rulerMotion", "Ruler motion", {
+  flipZone: {
+    label: "Flip zone px",
+    min: 60,
+    max: 600,
+    step: 10,
+    default: 200,
+    info: "Scroll distance over which the vertical-to-horizontal top flip plays out.",
+  },
+  detachZone: {
+    label: "Detach zone px",
+    min: 60,
+    max: 600,
+    step: 10,
+    default: 240,
+    info: "Scroll distance over which a queued heading morphs onto the rail beside its slot.",
+  },
+  stagger: {
+    label: "Letter stagger",
+    min: 0,
+    max: 0.3,
+    step: 0.01,
+    default: 0.16,
+    info: "Per-letter delay fraction in flips — higher = letters travel more one-by-one.",
+  },
+  arc: {
+    label: "Curve arc px",
+    min: 0,
+    max: 200,
+    step: 4,
+    default: 28,
+    info: "How far each letter's flight path bows inward (toward the page) mid-flip.",
+  },
+  jumpDur: {
+    label: "Jump dur s",
+    min: 0.2,
+    max: 2.5,
+    step: 0.05,
+    default: 1.25,
+    info: "Max duration of a click jump (rail or heading link); short hops scale it down.",
+  },
+  snapDelay: {
+    label: "Snap delay ms",
+    min: 100,
+    max: 1500,
+    step: 50,
+    default: 400,
+    info: "How long scroll must rest with a flip half-done before it auto-resolves.",
+  },
+  snapDur: {
+    label: "Snap dur s",
+    min: 0.2,
+    max: 2,
+    step: 0.05,
+    default: 0.7,
+    info: "Duration of the damped auto-scroll that resolves a half-done flip.",
+  },
+  introDur: {
+    label: "Intro dur s",
+    min: 0.1,
+    max: 2,
+    step: 0.05,
+    default: 1,
+    info: "Draw-in duration of each tick during the page-load cascade.",
+  },
+  introStagger: {
+    label: "Intro stag s",
+    min: 0,
+    max: 0.02,
+    step: 0.001,
+    default: 0.01,
+    info: "Delay between successive ticks in the load cascade (top-down).",
+  },
+  velRadius: {
+    label: "Vel radius px",
+    min: 0,
+    max: 500,
+    step: 10,
+    default: 180,
+    info: "Document distance around the needle within which ticks react to scroll speed.",
+  },
+  velMax: {
+    label: "Vel stretch",
+    min: 0,
+    max: 2,
+    step: 0.05,
+    default: 0.6,
+    info: "How much fast scrolling stretches the ticks nearest the needle.",
+  },
+  zoomInDelay: {
+    label: "Zoom delay ms",
+    min: 0,
+    max: 800,
+    step: 25,
+    default: 150,
+    info: "Hover intent time on the rail before the full-page zoom engages — accidental edge grazes don't fire.",
+  },
+  zoomOutDelay: {
+    label: "Unzoom delay ms",
+    min: 0,
+    max: 800,
+    step: 25,
+    default: 150,
+    info: "Grace period after leaving the rail before the zoom relaxes back to 1:1.",
+  },
+  zoomLerp: {
+    label: "Zoom damping",
+    min: 2,
+    max: 16,
+    step: 0.5,
+    default: 8,
+    info: "Damping rate of the zoom morph — higher = snappier compression onto the needle.",
+  },
+  dragLerp: {
+    label: "Drag lerp",
+    min: 0.05,
+    max: 0.6,
+    step: 0.01,
+    default: 0.18,
+    info: "How tightly the page chases the cursor while thumb-dragging the zoomed rail.",
+  },
+  heroLead: {
+    label: "Hero lead px",
+    min: 0,
+    max: 400,
+    step: 10,
+    default: 100,
+    info: "How many scroll px before the wordmark would duck under the nav the hero-to-header morph begins.",
+  },
+  heroZone: {
+    label: "Hero morph px",
+    min: 100,
+    max: 900,
+    step: 20,
+    default: 320,
+    info: "Scroll distance the hero wordmark's flight to the top heading slot spans.",
+  },
+});
+
+// Ink knobs — read per frame.
+export const rulerLookTuner = defineTunables("rulerLook", "Ruler look", {
+  minorAlpha: {
+    label: "Minor alpha",
+    min: 0,
+    max: 1,
+    step: 0.05,
+    default: 0.4,
+    info: "Opacity of the minor ticks.",
+  },
+  majorAlpha: {
+    label: "Major alpha",
+    min: 0,
+    max: 1,
+    step: 0.05,
+    default: 0.8,
+    info: "Opacity of labeled major ticks and the riding section ticks.",
+  },
+  labelAlpha: {
+    label: "Label alpha",
+    min: 0,
+    max: 1,
+    step: 0.05,
+    default: 0.5,
+    info: "Opacity of the mono percent numbers and section index labels.",
+  },
+  minorLen: {
+    label: "Minor len px",
+    min: 2,
+    max: 20,
+    step: 1,
+    default: 10,
+    info: "Length of minor ticks, drawn from the outer edge.",
+  },
+  majorLen: {
+    label: "Major len px",
+    min: 4,
+    max: 28,
+    step: 1,
+    default: 20,
+    info: "Length of labeled major ticks, drawn from the outer edge.",
+  },
+  ghostAlpha: {
+    label: "Ghost alpha",
+    min: 0,
+    max: 1,
+    step: 0.05,
+    default: 1,
+    info: "Opacity of the hover ghost line previewing where a rail click will jump.",
+  },
+  ghostThick: {
+    label: "Ghost thick px",
+    min: 1,
+    max: 8,
+    step: 1,
+    default: 3,
+    info: "Thickness of the hover ghost line.",
+  },
+  queueAlpha: {
+    label: "Queue alpha",
+    min: 0,
+    max: 1,
+    step: 0.05,
+    default: 0.35,
+    info: "Opacity of the compact heading links (bottom queue and top pile) and of the in-transit riding word — everything that isn't the active top heading.",
+  },
+  yieldPad: {
+    label: "Yield margin px",
+    min: 0,
+    max: 80,
+    step: 2,
+    default: 24,
+    info: "Distance around a riding word within which the tick percent labels fade out of its way (proximity yield).",
+  },
+  needleFadePct: {
+    label: "Needle fade %",
+    min: 0,
+    max: 10,
+    step: 0.5,
+    default: 3,
+    info: "Progress percent below which the needle and its readout fade out — the instrument stays quiet at the very top of the page.",
+  },
+  bracketAlpha: {
+    label: "Bracket alpha",
+    min: 0,
+    max: 0.5,
+    step: 0.02,
+    default: 0.1,
+    info: "Opacity of the shaded bracket marking the visible page span while zoomed.",
+  },
+  mapAlpha: {
+    label: "Map alpha",
+    min: 0,
+    max: 1,
+    step: 0.05,
+    default: 0.85,
+    info: "Opacity of the section labels in the zoomed full-page map.",
+  },
+});
diff --git a/frontend/apps/artcraft-website-next/src/components/ruler/scroll-ruler.tsx b/frontend/apps/artcraft-website-next/src/components/ruler/scroll-ruler.tsx
new file mode 100644
index 0000000000..a5ca5b770a
--- /dev/null
+++ b/frontend/apps/artcraft-website-next/src/components/ruler/scroll-ruler.tsx
@@ -0,0 +1,705 @@
+"use client";
+
+import { useEffect, useMemo, useRef, useState } from "react";
+import gsap from "gsap";
+import { HERO_SECTION_ID, RULER_SECTIONS } from "@/lib/landing-data";
+import { lenisRef } from "@/lib/lenis-ref";
+import { useTunerStore } from "@/lib/tuner";
+import HeadingFlow from "./heading-flow";
+import {
+  NAV_H,
+  clamp01,
+  easeOutExpo,
+  railOccupancy,
+  rulerMap,
+  rulerZoom,
+  type MeasuredSection,
+  type RulerMode,
+  type RulerSide,
+} from "./ruler-shared";
+import {
+  rulerLayoutTuner,
+  rulerLookTuner,
+  rulerMotionTuner,
+} from "./ruler-tunables";
+
+// The scroll ruler: a vertical instrument replacing the native scrollbar.
+//
+// The tick track is 1:1 with the document (tick p% sits at p% of the page)
+// and translates with scroll. The needle travels the viewport like a
+// scrollbar thumb — at progress p it sits p of the way down AND points
+// exactly at the tick labeled p, because the track carries a small
+// scroll-dependent offset (NAV_H·(1−p)) that reconciles the two mappings.
+// So ticks, needle, readout, and click targets always agree.
+//
+// Clicking the rail jumps to that progress (native-scrollbar semantics, via
+// Lenis so the jump is damped); the hover ghost previews the destination.
+// Section headings live in HeadingFlow: queued at the bottom (the navbar),
+// riding the track as vertical words, flipping horizontal into the top
+// stack. See DESIGN.md for the ideology this serves.
+//
+// Progressive enhancement: fine pointers on md+ get the full instrument
+// (native scrollbar hidden); reduced-motion visitors get a static rail and
+// keep their scrollbar; coarse pointers and small screens get nothing.
+export default function ScrollRuler() {
+  const [mode, setMode] = useState<RulerMode | null>(null);
+  const [geom, setGeom] = useState({ docH: 0, vh: 0, vw: 0 });
+  const [layoutVersion, setLayoutVersion] = useState(0);
+  const [sections, setSections] = useState<MeasuredSection[]>([]);
+
+  const railRef = useRef<HTMLDivElement>(null);
+  const trackRef = useRef<HTMLDivElement>(null);
+  const needleRef = useRef<HTMLDivElement>(null);
+  const readoutRef = useRef<HTMLSpanElement>(null);
+  const ghostRef = useRef<HTMLDivElement>(null);
+  const ghostLineRef = useRef<HTMLDivElement>(null);
+  const bracketRef = useRef<HTMLDivElement>(null);
+  const lineRefs = useRef<(HTMLSpanElement | null)[]>([]);
+  const tickRowRefs = useRef<(HTMLDivElement | null)[]>([]);
+  const labelRefs = useRef<(HTMLSpanElement | null)[]>([]);
+  const digitRefs = useRef<(HTMLSpanElement | null)[]>([]);
+
+  // Mutable per-frame state, never triggering React.
+  const fs = useRef({
+    vel: 0,
+    lastY: 0,
+    introDone: false,
+    prevDigits: [-1, -1, -1],
+    prevPct: -1,
+    readoutAbove: false,
+    geom: { docH: 0, vh: 0, vw: 0 },
+    zoomIntent: false,
+    zoomTimer: 0,
+    zoomWrote: false,
+    ghostActive: false,
+    ghostY: 0,
+    dragStartY: 0,
+    dragMoved: 0,
+  });
+  fs.current.geom = geom;
+
+  // Capability gate. Media changes mid-session are rare enough that a
+  // reload is the supported way to re-evaluate.
+  useEffect(() => {
+    const fine = window.matchMedia(
+      "(pointer: fine) and (min-width: 768px)",
+    ).matches;
+    if (!fine) return;
+    const motionOk = window.matchMedia(
+      "(prefers-reduced-motion: no-preference)",
+    ).matches;
+    setMode(motionOk ? "full" : "static");
+  }, []);
+
+  // Reset the shared zoom state (and its pending intent timer) on unmount
+  // so a remount never inherits a half-engaged zoom.
+  useEffect(() => {
+    const st = fs.current;
+    return () => {
+      window.clearTimeout(st.zoomTimer);
+      rulerZoom.target = 0;
+      rulerZoom.p = 0;
+      rulerZoom.dragging = false;
+    };
+  }, []);
+
+  // Structural tunables (layout + look) rebuild the rendered rail —
+  // debounced, same pattern as the hero wall.
+  useEffect(() => {
+    const snapshot = () =>
+      JSON.stringify([rulerLayoutTuner.read(), rulerLookTuner.read()]);
+    let last = snapshot();
+    let timer: ReturnType<typeof setTimeout> | undefined;
+    const unsubscribe = useTunerStore.subscribe(() => {
+      const now = snapshot();
+      if (now === last) return;
+      last = now;
+      clearTimeout(timer);
+      timer = setTimeout(() => setLayoutVersion((v) => v + 1), 250);
+    });
+    return () => {
+      clearTimeout(timer);
+      unsubscribe();
+    };
+  }, []);
+
+  const layout = useMemo(
+    () => rulerLayoutTuner.read(),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [layoutVersion, mode],
+  );
+  const look = useMemo(
+    () => rulerLookTuner.read(),
+    // eslint-disable-next-line react-hooks/exhaustive-deps
+    [layoutVersion, mode],
+  );
+  const side: RulerSide = layout.side >= 0.5 ? "right" : "left";
+  const railW = layout.railW;
+
+  // Stamp the mode on <html> so CSS can hide the scrollbar and reserve the
+  // rail gutter (JS-gated: no-JS visitors keep their scrollbar).
+  useEffect(() => {
+    if (!mode) return;
+    const root = document.documentElement;
+    root.dataset.ruler = mode === "full" ? "on" : "static";
+    root.dataset.rulerSide = side;
+    root.style.setProperty("--ruler-rail", `${railW}px`);
+    return () => {
+      delete root.dataset.ruler;
+      delete root.dataset.rulerSide;
+      root.style.removeProperty("--ruler-rail");
+    };
+  }, [mode, side, railW]);
+
+  // Page geometry. Guarded set: ResizeObserver fires on every body change
+  // and most of them don't move the numbers.
+  useEffect(() => {
+    if (!mode) return;
+    const measure = () => {
+      const next = {
+        docH: document.documentElement.scrollHeight,
+        vh: window.innerHeight,
+        vw: window.innerWidth,
+      };
+      setGeom((prev) =>
+        prev.docH === next.docH && prev.vh === next.vh && prev.vw === next.vw
+          ? prev
+          : next,
+      );
+    };
+    measure();
+    const ro = new ResizeObserver(measure);
+    ro.observe(document.body);
+    window.addEventListener("resize", measure);
+    document.fonts?.ready.then(measure).catch(() => {});
+    return () => {
+      ro.disconnect();
+      window.removeEventListener("resize", measure);
+    };
+  }, [mode]);
+
+  // Section anchors, resolved against the live DOM. (The hero's anchor is
+  // unused for motion — its morph is driven by the wordmark's own position
+  // in heading-flow — but measured uniformly anyway.)
+  useEffect(() => {
+    if (!mode || !geom.docH) return;
+    const out: MeasuredSection[] = [];
+    for (const s of RULER_SECTIONS) {
+      const el = document.getElementById(s.id);
+      if (!el) continue;
+      const rect = el.getBoundingClientRect();
+      const isHero = s.id === HERO_SECTION_ID;
+      const anchor = rect.top + window.scrollY;
+      out.push({
+        id: s.id,
+        label: s.label,
+        index: out.length,
+        anchor,
+        bottom: rect.bottom + window.scrollY,
+        isHero,
+      });
+    }
+    setSections(out);
+  }, [mode, geom, layoutVersion]);
+
+  // Tick roster: minor every `minorPct`, labeled major every `labelPct`.
+  const ticks = useMemo(() => {
+    if (!mode || !geom.docH) return [];
+    const out: { pct: number; docY: number; major: boolean; alpha: number }[] =
+      [];
+    for (let p = 0; p <= 100 + 1e-6; p += layout.minorPct) {
+      const pct = Math.round(p * 100) / 100;
+      const major = Math.abs(pct % layout.labelPct) < 1e-6;
+      out.push({
+        pct,
+        docY: (pct / 100) * geom.docH,
+        major,
+        alpha: major ? look.majorAlpha : look.minorAlpha,
+      });
+    }
+    lineRefs.current.length = out.length;
+    tickRowRefs.current.length = out.length;
+    labelRefs.current.length = out.length;
+    return out;
+  }, [mode, geom.docH, layout, look]);
+
+  // Intro cascade: ticks draw in from the outer edge, top-down, then the
+  // per-frame velocity writer takes over.
+  useEffect(() => {
+    if (mode !== "full" || !ticks.length) return;
+    const els = lineRefs.current.filter((el): el is HTMLSpanElement => !!el);
+    if (!els.length) return;
+    const mt = rulerMotionTuner.read();
+    fs.current.introDone = false;
+    const tween = gsap.fromTo(
+      els,
+      { scaleX: 0, opacity: 0 },
+      {
+        scaleX: 1,
+        opacity: (i: number) => ticks[i]?.alpha ?? 0.3,
+        duration: mt.introDur,
+        stagger: mt.introStagger,
+        ease: "power3.out",
+        overwrite: true,
+        onComplete: () => {
+          fs.current.introDone = true;
+        },
+      },
+    );
+    // No intro tween for the needle: its opacity is owned per-frame by the
+    // sub-N% progress fade (hidden at page top anyway).
+    return () => {
+      tween.kill();
+      fs.current.introDone = true;
+    };
+  }, [mode, ticks]);
+
+  // Frame loop: track sync, needle travel, odometer, velocity stretch.
+  useEffect(() => {
+    if (!mode || !geom.docH) return;
+    const full = mode === "full";
+    const tick = (_time: number, deltaMs: number) => {
+      const st = fs.current;
+      const { docH, vh } = st.geom;
+      if (!vh) return;
+      const dt = Math.min(deltaMs / 1000, 0.1) || 0.016;
+      const scrollY = window.scrollY;
+      const maxScroll = Math.max(1, docH - vh);
+      const progress = clamp01(scrollY / maxScroll);
+
+      const raw = (scrollY - st.lastY) / dt;
+      st.lastY = scrollY;
+      st.vel += (raw - st.vel) * (1 - Math.exp(-6 * dt));
+
+      const map = rulerMap(vh, rulerLayoutTuner.read().edgePad);
+      const drift = map.drift(progress);
+      if (trackRef.current) {
+        trackRef.current.style.transform = `translate3d(0, ${
+          -scrollY + drift
+        }px, 0)`;
+      }
+
+      const lk = rulerLookTuner.read();
+      const ny = map.base + progress * map.span;
+      if (needleRef.current) {
+        needleRef.current.style.transform = `translate3d(0, ${ny}px, 0)`;
+        // Quiet at the very top: the needle (and readout) fade in over the
+        // first few percent of progress instead of overlapping the hero.
+        needleRef.current.style.opacity = String(
+          clamp01(progress / Math.max(0.001, lk.needleFadePct / 100)),
+        );
+      }
+      const above = ny > vh - 26;
+      if (readoutRef.current && above !== st.readoutAbove) {
+        st.readoutAbove = above;
+        readoutRef.current.style.top = above ? "-14px" : "4px";
+      }
+
+      const pct = Math.round(progress * 100);
+      if (pct !== st.prevPct) {
+        st.prevPct = pct;
+        railRef.current?.setAttribute("aria-valuenow", String(pct));
+        const str = String(pct).padStart(3, "0");
+        for (let c = 0; c < 3; c++) {
+          const d = str.charCodeAt(c) - 48;
+          if (d !== st.prevDigits[c]) {
+            st.prevDigits[c] = d;
+            const col = digitRefs.current[c];
+            if (col) col.style.transform = `translateY(${-d}em)`;
+          }
+        }
+      }
+
+      // Zoom morph: hover intent (or an active drag) compresses the
+      // document-scale ruler onto the stationary needle — the needle's
+      // travel position IS tick p's compact position, so it never moves.
+      const mt = rulerMotionTuner.read();
+      if (full) {
+        rulerZoom.target = st.zoomIntent || rulerZoom.dragging ? 1 : 0;
+        rulerZoom.p +=
+          (rulerZoom.target - rulerZoom.p) * (1 - Math.exp(-mt.zoomLerp * dt));
+        if (rulerZoom.target === 0 && rulerZoom.p < 0.0005) rulerZoom.p = 0;
+        if (rulerZoom.target === 1 && rulerZoom.p > 0.9995) rulerZoom.p = 1;
+      }
+      const z = full ? rulerZoom.p : 0;
+
+      // Visible-span bracket, only meaningful in map space.
+      if (bracketRef.current) {
+        const b = bracketRef.current;
+        b.style.transform = `translate3d(0, ${
+          map.base + (scrollY / docH) * map.span
+        }px, 0)`;
+        b.style.height = `${(vh / docH) * map.span}px`;
+        b.style.opacity = String(z);
+      }
+
+      // Ghost follows the cursor; faint in 1:1 (its numbers are map-space),
+      // full strength once the map has formed.
+      if (ghostRef.current) {
+        const g = ghostRef.current;
+        if (st.ghostActive) {
+          g.style.transform = `translate3d(0, ${st.ghostY}px, 0)`;
+          g.style.opacity = String(lk.ghostAlpha * (0.2 + 0.8 * z));
+        } else {
+          g.style.opacity = "0";
+        }
+      }
+
+      // Tick layout + velocity response in one pass: each tick blends from
+      // its live 1:1 position toward its compact map position by z, and
+      // ticks near the needle stretch with scroll speed.
+      if (full && st.introDone && ticks.length) {
+        const needleDocY = progress * docH;
+        const velNorm = clamp01(Math.abs(st.vel) / 3000);
+        const writeZoom = z > 0 || st.zoomWrote;
+        const spans = railOccupancy.spans;
+        for (let i = 0; i < ticks.length; i++) {
+          const liveY = ticks[i].docY - scrollY + drift;
+          const compactY = map.base + (ticks[i].pct / 100) * map.span;
+          if (writeZoom) {
+            const row = tickRowRefs.current[i];
+            if (row) {
+              row.style.transform =
+                z > 0
+                  ? `translate3d(0, ${z * (compactY - liveY)}px, 0)`
+                  : "";
+            }
+          }
+
+          // Proximity yield: percent labels fade under a passing word and
+          // recover behind it. Fully zoomed, words leave the rail, so the
+          // yield eases out with z.
+          const lab = labelRefs.current[i];
+          if (lab) {
+            const y = liveY + z * (compactY - liveY);
+            let fade = 1;
+            if (lk.yieldPad > 0 && z < 1) {
+              for (const spn of spans) {
+                const d =
+                  y < spn.top
+                    ? spn.top - y
+                    : y > spn.bottom
+                      ? y - spn.bottom
+                      : 0;
+                if (d < lk.yieldPad) {
+                  // Distance-graded, scaled by the span's on-rail strength
+                  // so the yield ramps with the word's own transitions.
+                  const f = 1 - spn.k * (1 - d / lk.yieldPad);
+                  if (f < fade) fade = f;
+                }
+              }
+            }
+            lab.style.opacity = String(
+              lk.labelAlpha * (1 - (1 - fade) * (1 - z)),
+            );
+          }
+
+          const el = lineRefs.current[i];
+          if (!el) continue;
+          const dist = Math.abs(ticks[i].docY - needleDocY);
+          if (dist < mt.velRadius && mt.velRadius > 0) {
+            const t = 1 - dist / mt.velRadius;
+            const boost = velNorm * t * t;
+            el.style.transform = `scaleX(${1 + mt.velMax * boost})`;
+            el.style.opacity = String(
+              Math.min(1, ticks[i].alpha + 0.6 * boost),
+            );
+          } else {
+            el.style.transform = "scaleX(1)";
+            el.style.opacity = String(ticks[i].alpha);
+          }
+        }
+        st.zoomWrote = z > 0;
+      }
+    };
+    gsap.ticker.add(tick);
+    return () => {
+      gsap.ticker.remove(tick);
+    };
+  }, [mode, geom, ticks]);
+
+  if (!mode || !geom.docH) return null;
+
+  const sideStyle =
+    side === "right" ? { right: 0 as const } : { left: 0 as const };
+  const outerProp = side === "right" ? "right" : "left";
+
+  // Hover intent: the zoom engages/relaxes after a short beat so grazing
+  // the viewport edge doesn't fire it.
+  const scheduleZoom = (on: boolean) => {
+    const st = fs.current;
+    window.clearTimeout(st.zoomTimer);
+    const mt = rulerMotionTuner.read();
+    st.zoomTimer = window.setTimeout(
+      () => {
+        st.zoomIntent = on;
+      },
+      on ? mt.zoomInDelay : mt.zoomOutDelay,
+    );
+  };
+
+  const jumpTo = (clientY: number) => {
+    const st = fs.current;
+    const map = rulerMap(st.geom.vh, rulerLayoutTuner.read().edgePad);
+    const p = clamp01((clientY - map.base) / map.span);
+    const target = p * Math.max(1, st.geom.docH - st.geom.vh);
+    const lenis = lenisRef.current;
+    if (lenis) {
+      const mt = rulerMotionTuner.read();
+      const dist = Math.abs(target - window.scrollY);
+      lenis.scrollTo(target, {
+        duration:
+          mt.jumpDur * (0.4 + 0.6 * Math.min(1, dist / (st.geom.vh * 2.5))),
+        easing: easeOutExpo,
+      });
+    } else {
+      window.scrollTo({ top: target });
+    }
+  };
+
+  const railClick = (e: React.MouseEvent) => {
+    if (fs.current.dragMoved > 4) return; // that was a drag, not a click
+    jumpTo(e.clientY);
+    if (mode === "full" && ghostLineRef.current) {
+      gsap.fromTo(
+        ghostLineRef.current,
+        { opacity: 1 },
+        { opacity: rulerLookTuner.read().ghostAlpha, duration: 0.45 },
+      );
+    }
+  };
+
+  const railPointerEnter = () => {
+    scheduleZoom(true);
+  };
+
+  const railPointerLeave = () => {
+    fs.current.ghostActive = false;
+    if (!rulerZoom.dragging) scheduleZoom(false);
+  };
+
+  const railPointerMove = (e: React.PointerEvent) => {
+    const st = fs.current;
+    const map = rulerMap(st.geom.vh, rulerLayoutTuner.read().edgePad);
+    const y = Math.max(map.base, Math.min(map.base + map.span, e.clientY));
+    const p = clamp01((y - map.base) / map.span);
+    st.ghostActive = true;
+    st.ghostY = y;
+    // Absolute thumb drag: the page chases the cursor through Lenis's
+    // damping; release stops (no momentum).
+    if (rulerZoom.dragging) {
+      st.dragMoved = Math.max(
+        st.dragMoved,
+        Math.abs(e.clientY - st.dragStartY),
+      );
+      lenisRef.current?.scrollTo(
+        p * Math.max(1, st.geom.docH - st.geom.vh),
+        { lerp: rulerMotionTuner.read().dragLerp },
+      );
+    }
+  };
+
+  const railPointerDown = (e: React.PointerEvent) => {
+    e.preventDefault();
+    const st = fs.current;
+    st.dragStartY = e.clientY;
+    st.dragMoved = 0;
+    rulerZoom.dragging = true;
+    e.currentTarget.setPointerCapture(e.pointerId);
+  };
+
+  const railPointerUp = (e: React.PointerEvent) => {
+    if (!rulerZoom.dragging) return;
+    rulerZoom.dragging = false;
+    // Capture suppressed enter/leave while dragging — if the pointer let
+    // go outside the rail, relax the zoom ourselves.
+    const rect = railRef.current?.getBoundingClientRect();
+    const inside =
+      !!rect &&
+      e.clientX >= rect.left &&
+      e.clientX <= rect.right &&
+      e.clientY >= rect.top &&
+      e.clientY <= rect.bottom;
+    if (!inside) {
+      fs.current.ghostActive = false;
+      scheduleZoom(false);
+    }
+  };
+
+  return (
+    <>
+      {/* The rail: interactive scrollbar strip at the viewport edge. */}
+      <div
+        ref={railRef}
+        role="scrollbar"
+        aria-controls="main"
+        aria-orientation="vertical"
+        aria-valuemin={0}
+        aria-valuemax={100}
+        aria-valuenow={0}
+        aria-label="Page position"
+        className="fixed inset-y-0 z-40 cursor-crosshair overflow-hidden"
+        style={{ ...sideStyle, width: railW }}
+        onClick={railClick}
+        onPointerEnter={mode === "full" ? railPointerEnter : undefined}
+        onPointerLeave={mode === "full" ? railPointerLeave : undefined}
+        onPointerMove={mode === "full" ? railPointerMove : undefined}
+        onPointerDown={mode === "full" ? railPointerDown : undefined}
+        onPointerUp={mode === "full" ? railPointerUp : undefined}
+        onPointerCancel={mode === "full" ? railPointerUp : undefined}
+      >
+        {/* Tick track — 1:1 with the document, translated per frame. */}
+        <div
+          ref={trackRef}
+          aria-hidden
+          className="absolute inset-x-0 top-0"
+          style={{ height: geom.docH }}
+        >
+          {ticks.map((t, i) => (
+            <div
+              key={t.pct}
+              ref={(el) => {
+                tickRowRefs.current[i] = el;
+              }}
+              className="absolute inset-x-0"
+              style={{ top: t.docY, height: 0 }}
+            >
+              <span
+                ref={(el) => {
+                  lineRefs.current[i] = el;
+                }}
+                className="absolute block bg-ink"
+                style={{
+                  [outerProp]: 0,
+                  top: 0,
+                  width: t.major ? look.majorLen : look.minorLen,
+                  height: 1,
+                  opacity: mode === "full" ? 0 : t.alpha,
+                  transformOrigin: `${outerProp} center`,
+                }}
+              />
+              {t.major && (
+                <span
+                  ref={(el) => {
+                    labelRefs.current[i] = el;
+                  }}
+                  className="absolute -translate-y-1/2 font-mono text-ink"
+                  style={{
+                    [outerProp]: look.majorLen + 4,
+                    top: 0,
+                    fontSize: 9,
+                    letterSpacing: "0.08em",
+                    opacity: look.labelAlpha,
+                  }}
+                >
+                  {t.pct}
+                </span>
+              )}
+            </div>
+          ))}
+        </div>
+
+        {/* Visible-span bracket: the current viewport's slice of the page,
+            shown only while the zoomed map is formed. */}
+        {mode === "full" && (
+          <div
+            ref={bracketRef}
+            aria-hidden
+            className="absolute inset-x-0 top-0"
+            style={{ height: 0, opacity: 0 }}
+          >
+            <div
+              className="absolute inset-0 bg-ink"
+              style={{ opacity: look.bracketAlpha }}
+            />
+            <span
+              className="absolute inset-x-0 top-0 block bg-ink"
+              style={{ height: 1, opacity: 0.5 }}
+            />
+            <span
+              className="absolute inset-x-0 bottom-0 block bg-ink"
+              style={{ height: 1, opacity: 0.5 }}
+            />
+          </div>
+        )}
+
+        {/* Needle: travels [NAV_H, vh] with progress, meeting its tick. */}
+        <div
+          ref={needleRef}
+          aria-hidden
+          className="absolute inset-x-0 top-0"
+          style={{ height: 0 }}
+        >
+          <span
+            className="absolute inset-x-0 block bg-accent"
+            style={{ top: 0, height: 1, boxShadow: "0 0 6px var(--accent)" }}
+          />
+          <span
+            ref={readoutRef}
+            className="absolute whitespace-nowrap font-mono text-accent-ink"
+            style={{
+              [outerProp]: 2,
+              top: 4,
+              fontSize: 9,
+              letterSpacing: "0.08em",
+            }}
+          >
+            <span className="ruler-digits">
+              {[0, 1, 2].map((c) => (
+                <span
+                  key={c}
+                  ref={(el) => {
+                    digitRefs.current[c] = el;
+                  }}
+                  className="ruler-digit-col"
+                >
+                  {"0123456789".split("").map((d) => (
+                    <span key={d}>{d}</span>
+                  ))}
+                </span>
+              ))}
+            </span>
+            <span style={{ marginLeft: 2 }}>%</span>
+          </span>
+        </div>
+      </div>
+
+      {/* Hover ghost — destination preview, outside the rail so its label
+          can extend inward past the ticks. */}
+      {mode === "full" && (
+        <div
+          ref={ghostRef}
+          aria-hidden
+          className="pointer-events-none fixed inset-y-0 z-40"
+          style={{
+            ...sideStyle,
+            width: railW,
+            height: 0,
+            opacity: 0,
+            top: 0,
+          }}
+        >
+          <div
+            ref={ghostLineRef}
+            className="absolute block bg-ink"
+            style={{
+              [outerProp]: 0,
+              top: -look.ghostThick / 2,
+              width: railW,
+              height: look.ghostThick,
+              opacity: look.ghostAlpha,
+            }}
+          />
+        </div>
+      )}
+
+      <HeadingFlow
+        mode={mode}
+        side={side}
+        sections={sections}
+        geom={geom}
+        layoutVersion={layoutVersion}
+      />
+    </>
+  );
+}
diff --git a/frontend/apps/artcraft-website-next/src/lib/landing-data.ts b/frontend/apps/artcraft-website-next/src/lib/landing-data.ts
index aad973d568..1e634916bd 100644
--- a/frontend/apps/artcraft-website-next/src/lib/landing-data.ts
+++ b/frontend/apps/artcraft-website-next/src/lib/landing-data.ts
@@ -1,4 +1,4 @@
-import { mediaUrl } from "./links";
+import { cdnMediaUrl, mediaUrl } from "./links";
 
 // Product feature roster, ported from the shipping landing page. Copy is the
 // approved marketing copy — edit deliberately, not casually.
@@ -73,27 +73,45 @@ export const HERO_VIDEO_URL =
   "https://pub-f7441936e5804042a1ea2bdc92e4dc71.r2.dev/website-commercial-2026.05.mp4";
 
 // Clips for the hero's render wall. `aspect` is width/height of the panel
-// plane (the texture is cover-fitted, so any source aspect works).
-// Served through the /ext-media same-origin proxy (see next.config.ts) —
-// WebGL video textures require CORS-clean sources. PLACEHOLDERS: these
-// currently reuse the feature footage — swap each path for an exported
-// Seedance 2.5 clip when the renders are ready; the wall adapts to any
-// count and mix of aspects.
+// plane (the texture is cover-fitted, so any source aspect works), and the
+// wall adapts to any count and mix of aspects, so the count below is the
+// only thing to change when clips are added or dropped.
+//
+// Sources live on the FakeYou CDN as /videos/001.mp4 .. /videos/014.mp4 and
+// reach the page through the same-origin /cdn-media proxy, since WebGL video
+// textures require CORS-clean sources.
+const SHOWCASE_CLIP_COUNT = 14;
+
 export type SeedanceClip = {
   src: string;
   aspect: number;
 };
 
-export const SEEDANCE_SHOWCASE: SeedanceClip[] = [
-  { src: "/videos/1.mp4", aspect: 16 / 9 },
-  { src: "/videos/2.mp4", aspect: 16 / 9 },
-  { src: "/videos/3.mp4", aspect: 16 / 9 },
-  { src: "/videos/4.mp4", aspect: 16 / 9 },
-  { src: "/videos/5.mp4", aspect: 16 / 9 },
-  { src: "/videos/6.mp4", aspect: 16 / 9 },
-  { src: "/videos/7.mp4", aspect: 16 / 9 },
-  { src: "/videos/8.mp4", aspect: 16 / 9 },
-  { src: "/videos/9.mp4", aspect: 16 / 9 },
+export const SEEDANCE_SHOWCASE: SeedanceClip[] = Array.from(
+  { length: SHOWCASE_CLIP_COUNT },
+  (_, i) => ({
+    src: cdnMediaUrl(`/videos/${String(i + 1).padStart(3, "0")}.mp4`),
+    aspect: 16 / 9,
+  }),
+);
+
+// The scroll ruler's section roster, in document order. `id` must match a
+// DOM id on the page; sections missing from the DOM are silently skipped so
+// the ruler still works on future pages. The hero is special-cased by id
+// (its heading is the wordmark itself — see heading-flow.tsx).
+export type RulerSection = {
+  id: string;
+  label: string;
+};
+
+export const HERO_SECTION_ID = "hero";
+
+export const RULER_SECTIONS: RulerSection[] = [
+  { id: HERO_SECTION_ID, label: "ARTCRAFT" },
+  { id: "features", label: "FEATURES" },
+  { id: "ownership", label: "OWNERSHIP" },
+  { id: "made-with", label: "MADE WITH" },
+  { id: "start", label: "GET STARTED" },
 ];
 
 export const MADE_WITH_YOUTUBE_IDS = [
diff --git a/frontend/apps/artcraft-website-next/src/lib/lenis-ref.ts b/frontend/apps/artcraft-website-next/src/lib/lenis-ref.ts
new file mode 100644
index 0000000000..eca18ae831
--- /dev/null
+++ b/frontend/apps/artcraft-website-next/src/lib/lenis-ref.ts
@@ -0,0 +1,7 @@
+import type Lenis from "lenis";
+
+// The live Lenis instance, published by MotionProvider for anything that
+// needs programmatic smooth scrolling (the scroll ruler's jumps and snap).
+// null before mount and for reduced-motion visitors — consumers must fall
+// back to native scrolling.
+export const lenisRef: { current: Lenis | null } = { current: null };
diff --git a/frontend/apps/artcraft-website-next/src/lib/links.ts b/frontend/apps/artcraft-website-next/src/lib/links.ts
index 1ee4241a54..0e4f358366 100644
--- a/frontend/apps/artcraft-website-next/src/lib/links.ts
+++ b/frontend/apps/artcraft-website-next/src/lib/links.ts
@@ -18,6 +18,14 @@ export function mediaUrl(path: string): string {
   return `${MEDIA_BASE}${path.startsWith("/") ? path : `/${path}`}`;
 }
 
+// Showcase clips live on the FakeYou CDN, which serves no
+// Access-Control-Allow-Origin header. The hero wall draws them as WebGL
+// video textures, which require CORS-clean sources, so they go through the
+// same-origin /cdn-media rewrite (see next.config.ts).
+export function cdnMediaUrl(path: string): string {
+  return `/cdn-media${path.startsWith("/") ? path : `/${path}`}`;
+}
+
 export const SOCIAL_LINKS = {
   DISCORD: "https://discord.gg/artcraft",
   YOUTUBE: "https://www.youtube.com/@OfficialArtCraftStudios",
diff --git a/frontend/apps/artcraft-website-next/src/lib/tuner.ts b/frontend/apps/artcraft-website-next/src/lib/tuner.ts
index 18b3522e90..7b4e963997 100644
--- a/frontend/apps/artcraft-website-next/src/lib/tuner.ts
+++ b/frontend/apps/artcraft-website-next/src/lib/tuner.ts
@@ -16,6 +16,8 @@ export type TunableDef = {
   max: number;
   step: number;
   default: number;
+  /** One-liner shown behind the row's ⓘ hover — what the knob actually does. */
+  info?: string;
 };
 
 export type TunableGroup = {