Floating Cards 3D

Create a floating cards section with 3D depth.

Requirements:
- 5 to 7 glassmorphism cards positioned asymmetrically
- Each card floats at a different Y offset with slow infinite motion
- Subtle 3D tilt on hover (rotateX / rotateY based on cursor)
- Soft violet inner glow + backdrop-blur(24px)
- Mini charts, KPI numbers and activity items inside cards
- Framer Motion useSpring for the tilt
- Depth via shadow layers, no library
- Fully responsive (stacks vertically on mobile)
- 60fps, GPU accelerated

Feel: premium, floating, alive but calm. Inspired by Apple Vision, Linear and Stripe.

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TECHNICAL SPEC (must be respected)

Stack:
- React 18 + TypeScript (strict), Tailwind CSS, Framer Motion
- No extra animation library, no canvas unless explicitly required

Design tokens:
- Base background #0a0a0f, surfaces rgba(255,255,255,0.04)
- Borders rgba(255,255,255,0.08), primary violet #8b5cf6, secondary #a855f7
- Radius 20-28px, backdrop-blur(24px), inner highlight inset 0 1px 0 rgba(255,255,255,0.12)
- Typography: tight tracking on headings (-0.02em), 15-16px body, muted text at 60% opacity

Motion rules:
- Entrance: opacity 0 -> 1, y 24 -> 0, duration 0.7s, ease [0.16, 1, 0.3, 1]
- Stagger children by 0.06s, trigger with useInView({ once: true, margin: "-80px" })
- Hover: translateY(-6px) + soft violet glow, 250ms
- Animate only transform, opacity and filter. 60fps, will-change on animated layers
- Respect prefers-reduced-motion: disable loops, keep final states

Quality bar:
- Fully responsive (mobile-first, no horizontal scroll)
- Accessible: semantic HTML, focus-visible rings, contrast AA
- No layout shift, no dummy lorem ipsum, realistic copy
- Clean, reusable, production-ready components with typed props

Deliver the complete code, ready to paste, with no placeholder comments.