图片揭示

用 clipPath 从一条缝「擦开」，同时图片轻微 scale，是落地页最常见的配图入场。

gradient placeholder 
gsap.fromTo("#photo",
  { clipPath: "inset(0 100% 0 0)", scale: 1.15 },
  { clipPath: "inset(0 0% 0 0)", scale: 1, duration: 1.2, ease: "power4.inOut" }
);