background 04（17b79ab5）

Use this MotionSites background video as a looping website background asset.
Title: Background 04
Category: background
License: 付费
Video URL: https://d8j0ntlcm91z4.cloudfront.net/user_38xzZboKViGWJOttwIXH07lWA1P/hf_20260511_173438_a8ee28d2-70f7-4444-8797-8767d82bc834.mp4
Local thumbnail: thumbnails/17b79ab5-15c6-4631-823f-8768ae7d23c8.jpg
Implementation requirements:
- Render the video as a muted, autoplay, looped, playsInline background layer.
- Use object-fit: cover and keep the focal motion visible on desktop and mobile.
- Add a readable overlay only when foreground text needs contrast.
- Keep controls hidden for decorative background use, and provide a poster/thumbnail fallback.
- Respect the MotionSites authorization state before using this asset in a commercial project.