Stock Video Hero Background首屏背景视频治理

Select, license, optimize, and implement accessible stock video for website heroes, brand pages, and background b-roll, covering credit, release risk, posters, pause controls, and reduced motion.

为网页首屏、品牌页和背景 b-roll 选择、授权、优化并实现可访问的 stock video，覆盖署名、release 风险、poster、暂停控制和 reduced-motion。