feat(web): mobile-fit hero tiles + voluminous calmer particle field + FAQ accordion

Three coordinated polish items requested:

1. **Hero step-rotator tiles fit mobile without horizontal scroll.**
   The previous snippets contained a 50+ char `Live at https://notion-x9.mcp.buildmymcpserver.com` URL that overflowed the ~295 px text area on a 375 px viewport. Rewrote all three snippets to be naturally short — same product story, no full URLs. The <pre> drops `overflow-x-auto` and gains `whitespace-pre-wrap break-words` so any token that does exceed the column wraps gracefully instead of forcing a scrollbar.

2. **ParticleHero — more volumetric, slower, steadier at load-in.**
   The "stuttery / too fast" feedback came from two issues compounding: tiny dots (1.8 px on 256-tier, with 0.42 base alpha) gave the eye too few pixels to track between frames, so individual particles read as snapping rather than drifting; and the simplex-noise drift evolved at 0.08 time-scale with 0.045 velocity, fast enough that frame-to-frame deltas exceeded a tracked particle's diameter.

   Render uniforms tuned:
   - `uPointSize` 1.8 → 2.8 (256-tier), 2.4 → 3.6 (128-tier)
   - `uBaseAlpha` 0.42 → 0.60

   Simulation shader tuned:
   - Drift noise time scale 0.08 → 0.045 (the most impactful single change — particles now move at half the previous speed)
   - Drift velocity magnitude 0.045 → 0.028
   - Ring breathing noise time scale 0.35 → 0.22
   - Ring polar-wave time scales 1.2 / 0.7 → 0.7 / 0.42

   Net effect: same number of particles (65k) but each individually larger, brighter, and moving more slowly. The cumulative additive bloom is denser without the jitter that read as visual stutter.

3. **FAQ collapsed into a native `<details>` accordion.**
   Crawlers and screen readers still see every Q+A in the SSR'd HTML — `<details><summary>...</summary><p>answer</p></details>` is the standard semantic pattern for disclosure widgets. Users see one question at a time and expand on demand, which keeps the page from feeling like an endless wall of marketing text below the fold.

   Container narrowed `max-w-6xl` → `max-w-3xl` for accordion typography (long-form prose reads better single-column). The default WebKit disclosure-triangle marker is suppressed with `list-none` + `[&_summary::-webkit-details-marker]:hidden`, and a `lucide-react` `ChevronDown` icon rotates 180° via `group-open:rotate-180` to indicate state.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

apps/web/app/(marketing)/page.tsx

@@ -5,6 +5,7 @@ import { PulseLink } from '@/components/pulse';
 import { ScrollCue } from '@/components/scroll-cue';
 import { StaticCodeBlock } from '@/components/static-code-block';
 import { FAQ, faqJsonLd } from '@/lib/seo';
+import { ChevronDown } from 'lucide-react';
 import Link from 'next/link';
 
 const PROMPT_EXAMPLE = `Create an MCP server that searches our Notion workspace.
@@ -351,17 +352,33 @@ export default function Landing() {
         </div>
       </section>
 
-      {/* FAQ */}
+      {/* FAQ — collapsible accordion using native <details>. Crawlers
+          and screen readers still see the full Q+A in the HTML; users
+          see one question at a time and expand on demand. No JS, no
+          state, semantically correct. `list-none` + the WebKit-marker
+          pseudo-class suppress the default disclosure triangle so we
+          can render our own chevron that rotates via `group-open`. */}
       <section className="py-14 sm:py-20">
         <JsonLd data={faqJsonLd()} />
-        <div className="mx-auto max-w-6xl px-6">
+        <div className="mx-auto max-w-3xl px-6">
           <h2 className="text-[28px] font-semibold tracking-tight">FAQ</h2>
-          <div className="mt-8 grid gap-x-12 gap-y-6 md:grid-cols-2">
+          <div className="mt-8 border-t border-[--color-border]">
             {FAQ.map((f) => (
-              <div key={f.q}>
-                <h3 className="text-[14px] font-semibold tracking-tight">{f.q}</h3>
-                <p className="mt-1.5 text-[13px] leading-relaxed text-[--color-fg-muted]">{f.a}</p>
-              </div>
+              <details
+                key={f.q}
+                className="group border-b border-[--color-border] [&_summary::-webkit-details-marker]:hidden"
+              >
+                <summary className="flex cursor-pointer list-none items-center justify-between gap-4 py-4 text-[14.5px] font-semibold tracking-tight text-[--color-fg] transition-colors hover:text-[--color-accent]">
+                  <span>{f.q}</span>
+                  <ChevronDown
+                    size={16}
+                    className="shrink-0 text-[--color-fg-subtle] transition-transform duration-200 group-open:rotate-180 group-open:text-[--color-accent]"
+                  />
+                </summary>
+                <p className="pb-5 pr-8 text-[13.5px] leading-relaxed text-[--color-fg-muted]">
+                  {f.a}
+                </p>
+              </details>
             ))}
           </div>
         </div>