Use this MotionSites background video as a looping website background asset. Title: Ethereal Smoke Category: background License: 免费 Video URL: https://stream.mux.com/Si6ej2ZRrxRCnTYBXSScDRCdd7CGnyTqiPszZcw3z4I.m3u8 Local thumbnail: thumbnails/e4f0e89d-bea7-4786-a64a-425219aa9119.png 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.