Swipe Deck Testimonials

Build a "Swipe Deck Testimonials" React component.

CONCEPT: Client testimonials presented as a physical deck of index cards. Drag the top card past a threshold (120px or fast velocity) to throw it; the stack advances and loops.

LAYOUT & CONTENT:
- Cards 280x190 with alternating fills (paper, terracotta-soft #F6DCD9, cobalt-soft #DBE4FB), 1px charcoal border, quote in a serif italic, client name + role in mono.
- Show 3 cards stacked with offsets y 8px and scale 0.96 per depth.
- Prev/Next buttons beneath for keyboard and accessibility.

INTERACTIONS & MOTION:
- Top card: drag='x', rotate = useTransform(x, [-200, 200], [-14, 14]).
- onDragEnd: if |offset.x| > 120 or |velocity.x| > 600, animate x off-screen in that direction then move the card to the back of the array; otherwise spring back.
- Lower cards animate scale/y into new positions with spring stiffness 300 damping 25.

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".