Hero: reinstate the ambient loop as a split layout, done right

Bring back the reference's hero ambient — text left, looping WebM right — but
fixed: self-hosted (62KB, off Manus's S3), poster-first with a paper-tinted
container so it's NEVER blank, and loaded via JS only when appropriate (skipped
on Save-Data and prefers-reduced-motion; poster stays if autoplay is blocked).
No autoplay attribute = no surprise download. Poster image added next.

Co-Authored-By: Claude Opus 4.8 <noreply@anthropic.com>

style.css

@@ -127,6 +127,15 @@ a.tel { text-decoration: none; }
 .hero h1 { margin-bottom: 0.35em; }
 .lead { font-size: 1.25rem; line-height: 1.7; color: var(--ink-soft); margin-bottom: 2.4em; }
 
+/* Hero split — text left, ambient loop right. Poster-first + paper fallback = never blank. */
+.hero-wrap { display: grid; grid-template-columns: 1.05fr 0.9fr; gap: clamp(2rem, 5vw, 4.5rem); align-items: center; }
+.hero-media { position: relative; border-radius: 10px; overflow: hidden; background: var(--paper-2); aspect-ratio: 1 / 1; }
+.hero-video { width: 100%; height: 100%; object-fit: cover; display: block; }
+@media (max-width: 860px) {
+  .hero-wrap { grid-template-columns: 1fr; gap: 2.2rem; }
+  .hero-media { aspect-ratio: 16 / 10; max-height: 320px; }
+}
+
 .actions { display: flex; align-items: center; gap: 28px; flex-wrap: wrap; }
 .actions.center { justify-content: center; }
 .btn {