Fix orange dot/hero image visibility, arrow alignment, and add a mobile legal-page TOC

- PopIn (Home Hero's brand dot) switched from whileInView to animate — its
  translate-based entrance could push the element off-screen on a narrow
  phone before the IntersectionObserver ever saw it as visible, leaving it
  stuck invisible permanently.
- Hero image: no longer wrapped in Reveal below lg: — whileInView's margin
  meant it stayed at opacity:0 (a white gap above the fold) on short mobile
  viewports until scrolled. Reveal's fade-in kept from lg: up.
- "→ Label" CTA links (Tools.tsx, Blog.tsx) now use a flex row with the
  arrow as its own span instead of a literal inline "→" character, which
  doesn't reliably align to the surrounding text's cap-height.
- Replaced icon-arrow-connector.svg with a new shared StepArrow component
  (inline SVG) across all three step sections — the old asset's color
  couldn't be overridden from outside the SVG file, so it could never
  actually become brand-orange. Bigger and better-shaped below the
  structural breakpoint per feedback.
- Added MobileSectionTOC (SectionTOC.tsx) — a <details> accordion shown
  below lg: on Impressum/Datenschutz/AGB/Widerruf/Versand, which previously
  had no on-page navigation aid at all below lg: (the sidebar TOC is
  `hidden` entirely there).
- Updated the figma-to-nextjs skill with 8 new dated Gotchas from this
  mobile-responsive pass, and expanded Step 6's verification checklist.
- README: new "Mobile responsive pass" section summarizing the above.

app/components/SectionTOC.tsx

@@ -10,24 +10,12 @@ export type TOCSection = { id: string; title: string };
 // active state away from what was actually clicked.
 const CLICK_OVERRIDE_MS = 1000;
 
-// lg:-only sidebar — same "wide fixed-width block next to content" shape
-// as the cart's order-summary sidebar (see figma-to-nextjs skill Gotcha
-// #5): a 360px TOC card plus a readable content column already exceeds
-// the 768px Tablet floor, so md: wouldn't leave room for a real 2-column
-// split at Tablet widths.
-//
-// Generic over `sections` — originally written just for /versand
-// (VersandTOC), generalized once /datenschutz needed the identical
-// scroll-spy sidebar but driven by CMS-authored headings instead of a
-// hardcoded array. Any future long legal/content page reuses this too.
-//
-// Not sticky itself — Impressum/Datenschutz put an extra card below this
-// in the same sidebar column, and if only this <nav> were sticky, the
-// card (a plain-flow sibling) would scroll away independently instead of
-// travelling with it. The caller wraps whatever the sidebar column
-// contains (this alone, or this + more) in `lg:sticky lg:top-32
-// lg:self-start` so the whole column moves as one unit.
-export function SectionTOC({ sections }: { sections: TOCSection[] }) {
+// Shared between SectionTOC (desktop sidebar nav) and MobileSectionTOC
+// (below lg: collapsible accordion, added 2026-07-24) — both need the same
+// scroll-spy "active" state and click-override handling, just render it
+// completely differently, so the logic lives here once instead of being
+// duplicated per component.
+function useActiveSection(sections: TOCSection[]) {
   const [active, setActive] = useState<string>(sections[0]?.id ?? "");
   // Not state — read inside the IntersectionObserver callback without
   // needing to re-subscribe it on every click, and cleared by its own
@@ -67,6 +55,28 @@ export function SectionTOC({ sections }: { sections: TOCSection[] }) {
     }, CLICK_OVERRIDE_MS);
   }
 
+  return { active, handleClick };
+}
+
+// lg:-only sidebar — same "wide fixed-width block next to content" shape
+// as the cart's order-summary sidebar (see figma-to-nextjs skill Gotcha
+// #5): a 360px TOC card plus a readable content column already exceeds
+// the 768px Tablet floor, so md: wouldn't leave room for a real 2-column
+// split at Tablet widths.
+//
+// Generic over `sections` — originally written just for /versand
+// (VersandTOC), generalized once /datenschutz needed the identical
+// scroll-spy sidebar but driven by CMS-authored headings instead of a
+// hardcoded array. Any future long legal/content page reuses this too.
+//
+// Not sticky itself — every caller wraps this in its own `hidden lg:flex
+// ... lg:sticky lg:top-32 lg:self-start` div (Impressum/Datenschutz also
+// stack a second "Nachhaltigkeit" card below this in that same wrapper, so
+// the sticky behavior has to live on the wrapper for the two to travel
+// together as one unit — putting it on this <nav> instead would leave
+// that card behind as a plain-flow sibling scrolling past a now-fixed nav).
+export function SectionTOC({ sections }: { sections: TOCSection[] }) {
+  const { active, handleClick } = useActiveSection(sections);
   if (sections.length === 0) return null;
 
   return (
@@ -92,3 +102,44 @@ export function SectionTOC({ sections }: { sections: TOCSection[] }) {
     </nav>
   );
 }
+
+// Below lg: only — a collapsible accordion instead of the sidebar nav
+// (which is `hidden` entirely below lg:, see SectionTOC's own comment on
+// why a real 2-column split doesn't fit there). Added 2026-07-24: these
+// legal pages had no on-page navigation aid at all on Mobile/Tablet, which
+// is exactly where scanning a long legal document by scrolling is hardest.
+// Native <details>/<summary> — no extra open/close state needed, and it
+// stays open after a click so jumping between sections doesn't require
+// reopening it each time. Render this as its own element in the page
+// (typically right after the heading, before the two-column content row),
+// not nested inside a parent that's itself `hidden lg:...` — that would
+// hide this too regardless of its own lg:hidden class.
+export function MobileSectionTOC({ sections }: { sections: TOCSection[] }) {
+  const { active, handleClick } = useActiveSection(sections);
+  if (sections.length === 0) return null;
+
+  return (
+    <details className="lg:hidden w-full bg-bg-base border border-border rounded-md p-4 open:pb-2">
+      <summary className="text-label font-semibold text-text-muted uppercase tracking-wide cursor-pointer select-none">
+        Inhaltsübersicht
+      </summary>
+      <div className="flex flex-col gap-1 mt-3">
+        {sections.map(({ id, title }) => (
+          <a
+            key={id}
+            href={`#${id}`}
+            onClick={() => handleClick(id)}
+            className={
+              "px-3 py-2 rounded-sm text-body-sm transition-colors border-l-2 " +
+              (active === id
+                ? "border-toc-active-border bg-bg-muted text-text-primary font-semibold"
+                : "border-transparent text-text-muted hover:text-text-primary")
+            }
+          >
+            {title}
+          </a>
+        ))}
+      </div>
+    </details>
+  );
+}