/* 三个方向共用的底子：重置、本地字体栈、按行拆开的文案、视频兜底。
   字体只用系统自带（离线可开）：苹果上是宋体 / 苹方，Windows 是宋体 / 雅黑。 */
:root {
  --serif: "Songti SC", "STSong", "Noto Serif SC", "Source Han Serif SC", "SimSun", serif;
  --sans: "PingFang SC", "Hiragino Sans GB", "Noto Sans SC", "Microsoft YaHei", system-ui, sans-serif;
}
*, *::before, *::after { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; scroll-behavior: smooth; }
body { margin: 0; font-family: var(--sans); line-height: 1.7; -webkit-font-smoothing: antialiased; }
img, video { display: block; max-width: 100%; }
h1, h2, h3, h4, p, figure { margin: 0; }
h1 { text-wrap: balance; }
button { font: inherit; color: inherit; cursor: pointer; }

/* copy.js 里的数组：每项一行；窄屏放不下时行内仍可折 */
.ln { display: block; }

/* 每段自成一块，可以单独截图 */
.seg { position: relative; overflow: hidden; }

/* 视频不能播时只留静帧 */
[data-video] .hero-still { position: absolute; inset: 0; width: 100%; height: 100%; object-fit: cover; }
[data-video] .hero-video { position: relative; }
[data-video].no-video .hero-video,
[data-video].no-video .sound { display: none; }

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  *, *::before, *::after { animation: none !important; transition: none !important; }
}