动效背景｜Animated Gradient Background / Animated Gradient Background

You are an expert frontend engineer. Rebuild this UI to match the dynamic preview video exactly.
Component: Animated Gradient Background
Preview source: 21st.dev component preview
Preview video: https://cdn.21st.dev/user_2raao7ewdsV3POoFtbzjac3ufnv/animated-gradient-background/default/video.mp4
Poster: https://cdn.21st.dev/user_2raao7ewdsV3POoFtbzjac3ufnv/animated-gradient-background/default/preview.1788464039693.png
Stack: React + Tailwind CSS + Framer Motion.
Requirements:
- Match composition, hierarchy, spacing, color, and motion
- Production-ready, responsive, accessible
- Ship only this component/section
Deliver: 1) code 2) Tailwind 3) motion 4) ZH+EN microcopy

动效背景｜Animated Gradient Background / Animated Gradient Background

卡片与弹窗均为动态视频预览（静音循环）。复制提示词需 10 积分。

预览来源：21st.dev