Editorial FAQ Accordion

Build a "Editorial FAQ Accordion" React component.

CONCEPT: A frequently-asked-questions block styled like a printed index: big numbers, tight grotesk questions, serif answers, and a single-open accordion behavior.

LAYOUT & CONTENT:
- Four questions: 'How long does a site take?', 'Do you start from a template?', 'Who writes the copy?', 'What happens after launch?' with real 1–2 sentence answers.
- Each row: mono number 01–04, question, plus icon on the right in a 28px circle; rows separated by 1px charcoal rules.

INTERACTIONS & MOTION:
- Answer panel animates height 0 → 'auto' and opacity with AnimatePresence initial={false}, spring stiffness 300 damping 32.
- Plus icon rotates 45° (becoming ×) and the circle fills charcoal when open.
- The open question text shifts 6px right. Buttons have aria-expanded and aria-controls.

DESIGN SYSTEM (non-negotiable):
- Palette: paper background #FAF9F6, deep charcoal #121212 for text and 1px borders, ONE warm accent: cobalt #1D4ED8 or terracotta #D9534F. Secondary surface #F2EFE8.
- Typography: Swiss / editorial. A tight grotesk for UI (Instrument Sans, Inter Tight or similar) with negative tracking on display sizes; an italic serif (Instrument Serif) used sparingly for one emphasized word.
- NO dark-mode neon, NO glow, NO glassmorphism, NO backdrop blur, NO purple-to-blue gradients, NO emoji icons. Solid fills, hairline rules, honest shadows (hard offset or none).
- Motion: Framer Motion with spring physics (type: "spring", stiffness 300-500, damping 20-35). Animate transform and opacity only. Respect prefers-reduced-motion via useReducedMotion().
- Icons: lucide-react, 1.5px stroke.
- Accessibility: real <button>/<a>/<label> elements, visible focus ring (2px cobalt, 3px offset), keyboard operable, aria attributes where state changes.

OUTPUT: one self-contained React component file (Tailwind CSS v4 utility classes, framer-motion, lucide-react), no external images, default export, ready to paste into a Next.js App Router page with "use client".