background 03（6ff103a1）

Use this MotionSites background video as a looping website background asset.
Title: Background 03
Category: background
License: 免费
Video URL: https://d8j0ntlcm91z4.cloudfront.net/user_38xzZboKViGWJOttwIXH07lWA1P/hf_20260511_214311_24de0b75-7eaa-4f42-86d8-8c2014ca2851.mp4
Local thumbnail: thumbnails/6ff103a1-acd6-44f5-beaa-e9b7468c80a2.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.