:root {
  color-scheme: light dark;
  --paper: #f8f6f0;
  --surface: #fffdf8;
  --soft: #f1eee6;
  --rule: #e5e1d7;
  --lime: #d5eb82;
  --blue: #0868e7;
  --link: #064da8;
  --ink: #162237;
  --muted: #4d5968;
  --button-ink: #162237;
  scroll-padding-top: 4.5rem;
  font: 100%/1.65 system-ui, "Segoe UI", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  background: var(--paper);
}
*, *::before, *::after { box-sizing: border-box; }
body { margin: 0; }
a { color: var(--link); text-underline-offset: .2em; }
a:hover { text-decoration-thickness: 2px; }
a:focus-visible { outline: 3px solid var(--blue); outline-offset: 4px; border-radius: 4px; }
.frame { width: min(72rem, 100% - 3rem); margin-inline: auto; }
.top { position: sticky; top: 0; z-index: 100; border-bottom: 1px solid var(--rule); background: var(--surface); box-shadow: 0 1px 12px #12365d0d; }
.top-inner, .footer-inner { display: flex; align-items: center; justify-content: space-between; gap: 1rem 2rem; flex-wrap: wrap; padding-block: 1rem; }
.wordmark { display: inline-flex; align-items: center; gap: .55rem; color: var(--ink); font-size: 1.18rem; font-weight: 800; letter-spacing: .09em; text-decoration: none; white-space: nowrap; }
.wordmark img { display: block; flex: none; }
.wordmark-accent { color: var(--link); font-weight: 650; letter-spacing: 0; }
nav { display: flex; flex-wrap: wrap; gap: .5rem 1.35rem; align-items: center; }
nav a { color: var(--ink); font-size: .95rem; font-weight: 600; text-decoration: none; }
nav a:hover, [aria-current="page"] { color: var(--link); text-decoration: underline; }
.language { position: relative; }
.language summary { cursor: pointer; font-size: .95rem; font-weight: 600; }
.language summary:focus-visible { outline: 3px solid var(--blue); outline-offset: 4px; }
.language ul { position: absolute; inset-inline-end: 0; width: max-content; max-width: min(15rem, calc(100vw - 2rem)); max-height: min(55vh, 24rem); overflow: auto; margin: .4rem 0 0; padding: .45rem; list-style: none; background: var(--surface); border: 1px solid var(--rule); border-radius: .5rem; box-shadow: 0 .6rem 1.8rem #0003; }
.language a { display: block; padding: .35rem .65rem; }
.hero { display: grid; grid-template-columns: 1.1fr .9fr; gap: clamp(1.8rem, 5vw, 5rem); align-items: center; padding-block: clamp(2.5rem, 7vw, 6rem) 2rem; }
.eyebrow { color: var(--link); font-weight: 750; font-size: .86rem; letter-spacing: .1em; text-transform: uppercase; }
h1, h2, h3 { line-height: 1.15; margin: 0 0 .65em; }
h1 { font-size: clamp(2.1rem, 5.5vw, 4.5rem); letter-spacing: -.055em; overflow-wrap: anywhere; }
h2 { font-size: clamp(1.42rem, 3vw, 2rem); letter-spacing: -.025em; }
h3 { font-size: 1.23rem; }
p { margin-block: 0 1.05em; }
.lead { font-size: clamp(1.16rem, 2.3vw, 1.55rem); font-weight: 650; }
.hero-copy > p:not(.eyebrow, .lead), .card p, .edition { color: var(--muted); }
.actions { display: flex; align-items: center; gap: .7rem; flex-wrap: wrap; margin-block: 1.45rem; }
.button { display: inline-block; color: var(--button-ink); background: var(--lime); padding: .65rem 1.1rem; border: 1px solid transparent; border-radius: .5rem; font-weight: 700; text-decoration: none; }
.button:hover { text-decoration: underline; }
.secondary { color: var(--ink); background: var(--surface); border-color: var(--rule); }
.hero-art { display: grid; justify-items: center; gap: 1.5rem; padding: clamp(1.2rem, 4vw, 3.7rem); border-radius: 1.4rem; color: white; background: radial-gradient(ellipse at 55% 12%, #20518a, #12233d 62%, #10192b); }
.device-icon { display: grid; place-items: center; width: min(100%, 14rem); aspect-ratio: 1; border-radius: 26%; box-shadow: inset 0 1px 2px #ffffff50, 0 1.2rem 2.2rem #0007; }
.device-icon img { display: block; width: 100%; height: auto; }
.art-caption { display: flex; flex-wrap: wrap; justify-content: center; gap: .6rem 1.2rem; color: #f1f5fc; font-size: .76rem; letter-spacing: .12em; font-weight: 750; }
.art-caption span { color: var(--lime); }
.notice { padding: .9rem 1.1rem; border-inline-start: .25rem solid var(--blue); border-radius: .25rem; background: var(--soft); }
.features { padding-block: 2rem 3.8rem; }
.cards { display: grid; grid-template-columns: repeat(4, 1fr); gap: 1rem; }
.card { padding: 1.3rem; border: 1px solid var(--rule); border-radius: .8rem; background: var(--surface); }
.card p { margin-bottom: 0; }
.number { display: inline-block; color: var(--link); font-weight: 800; margin-bottom: .8rem; }
.article { max-width: 49rem; padding-block: clamp(2.5rem, 6vw, 5rem); overflow-wrap: anywhere; }
.article h1 { font-size: clamp(2rem, 5vw, 3.65rem); }
.article section { border-top: 1px solid var(--rule); padding-top: 1.3rem; margin-top: 1.3rem; scroll-margin-top: 1rem; }
.contents { padding: .65rem 1rem .65rem 2rem; background: var(--surface); border: 1px solid var(--rule); border-radius: .5rem; }
.walkthrough { display: grid; grid-template-columns: 1fr minmax(11rem, 34%); gap: 1.4rem; align-items: start; }
.walkthrough-steps { margin: 0; padding-inline-start: 1.5rem; }
.walkthrough-steps li { padding-inline-start: .2rem; margin-block-end: .85rem; }
.walkthrough figure { margin: 0; padding: .6rem; background: var(--surface); border: 1px solid var(--rule); border-radius: .7rem; }
.walkthrough video { display: block; width: 100%; height: auto; border-radius: .35rem; }
footer { border-top: 1px solid var(--rule); color: var(--muted); background: var(--surface); font-size: .9rem; }
@media (max-width: 55rem) { .cards { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 40rem) {
  :root { scroll-padding-top: 7rem; }
  .frame { width: min(100% - 2rem, 72rem); }
  .hero, .cards { grid-template-columns: 1fr; }
  .walkthrough { grid-template-columns: 1fr; }
  .walkthrough figure { width: min(100%, 18rem); }
  .top-inner nav { position: relative; width: 100%; }
  .language { position: static; }
  .language ul { inset-inline: 0 auto; }
  .hero-art { padding: 1.4rem; }
  .device-icon { width: min(100%, 10rem); }
  .top-inner { gap: .7rem; }
}
@media (max-width: 22rem) { :root { scroll-padding-top: 8.5rem; } }
@media (prefers-color-scheme: dark) {
  :root {
    --paper: #101316;
    --surface: #20252a;
    --soft: #282e34;
    --rule: #454e57;
    --blue: #80baff;
    --link: #9dccff;
    --ink: #f1f4f6;
    --muted: #c1cad2;
  }
  body { min-height: 100vh; background: linear-gradient(145deg, #383d43 0, #20252a 20rem, #101316 53rem); }
  .hero-art { background: radial-gradient(ellipse at 55% 12%, #383d43, #20252a 62%, #101316); border: 1px solid var(--rule); }
}