:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --text: #0f1726;
  --muted: #5b6475;
  --line: #e3e8f0;
  --brand: #0a6cff;
  --brand-deep: #0041b8;
  --brand-soft: #e8f1ff;
  --ok: #1f9d55;
  --radius: 20px;
  --shadow: 0 1px 2px rgba(15, 23, 38, .04), 0 8px 24px rgba(15, 23, 38, .06);
}
@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b0f17;
    --surface: #141a25;
    --text: #eef2f8;
    --muted: #9aa4b6;
    --line: #232b39;
    --brand: #3d8bff;
    --brand-deep: #9cc2ff;
    --brand-soft: #16233a;
    --ok: #3ccf7d;
    --shadow: 0 1px 2px rgba(0, 0, 0, .3), 0 8px 24px rgba(0, 0, 0, .35);
  }
}

* { box-sizing: border-box; }
html { -webkit-text-size-adjust: 100%; }
body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font: 16px/1.7 -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB", "Microsoft YaHei", "Helvetica Neue", sans-serif;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--brand); text-decoration: none; }
a:hover { text-decoration: underline; }

.wrap { max-width: 1080px; margin: 0 auto; padding: 0 20px; }

/* 顶栏 */
.nav {
  position: sticky; top: 0; z-index: 10;
  background: color-mix(in srgb, var(--bg) 82%, transparent);
  backdrop-filter: saturate(180%) blur(16px);
  -webkit-backdrop-filter: saturate(180%) blur(16px);
  border-bottom: 1px solid var(--line);
}
.nav .wrap { display: flex; align-items: center; justify-content: space-between; height: 60px; }
.brand { display: flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; font-size: 18px; }
.brand:hover { text-decoration: none; }
.brand img { width: 32px; height: 32px; border-radius: 8px; }
.nav-links { display: flex; gap: 22px; font-size: 15px; white-space: nowrap; }
.brand { white-space: nowrap; }
.nav-links a { color: var(--muted); }
.nav-links a:hover, .nav-links a[aria-current="page"] { color: var(--text); text-decoration: none; }

/* 首屏 */
.hero { padding: 48px 0 40px; }
.hero .wrap { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: center; }
.eyebrow {
  display: inline-block; padding: 4px 12px; border-radius: 999px;
  background: var(--brand-soft); color: var(--brand); font-size: 14px; font-weight: 600;
}
.hero h1 { font-size: clamp(34px, 5vw, 52px); line-height: 1.15; margin: 18px 0 16px; letter-spacing: -.5px; }
.hero h1 .accent { color: var(--brand); }
.hero p.lead { font-size: 18px; color: var(--muted); margin: 0 0 28px; max-width: 34em; }
.cta { display: flex; flex-wrap: wrap; gap: 12px; align-items: center; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 22px; border-radius: 12px; font-weight: 600; font-size: 16px;
  background: var(--brand); color: #fff;
}
.btn:hover { text-decoration: none; background: var(--brand-deep); color: #fff; }
.btn.ghost { background: transparent; color: var(--text); border: 1px solid var(--line); }
.btn.ghost:hover { background: var(--surface); color: var(--text); }
.note { color: var(--muted); font-size: 14px; }

.phone {
  justify-self: center; width: min(270px, 72vw);
  border-radius: 40px; padding: 9px; background: #0d1117;
  box-shadow: 0 30px 60px rgba(10, 60, 160, .25), 0 0 0 1px rgba(255, 255, 255, .06) inset;
}
.phone img { border-radius: 32px; }
.hero-art { justify-self: center; width: min(500px, 100%); }
.hero-art img { width: 100%; height: auto; }

/* 区块 */
section { padding: 56px 0; }
.section-title { text-align: center; margin: 0 auto 36px; max-width: 40em; }
.section-title h2 { font-size: clamp(26px, 3.6vw, 34px); margin: 0 0 8px; letter-spacing: -.3px; }
.section-title p { color: var(--muted); margin: 0; }

.grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.card {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; box-shadow: var(--shadow);
}
.card .icon {
  width: 44px; height: 44px; border-radius: 12px; display: grid; place-items: center;
  background: var(--brand-soft); color: var(--brand); margin-bottom: 14px;
}
.card .icon svg { width: 24px; height: 24px; }
.card h3 { margin: 0 0 6px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); font-size: 15px; }

/* 截图 */
.shots { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.shot figure { margin: 0; }
.shot img { border-radius: 28px; border: 1px solid var(--line); box-shadow: var(--shadow); }
.shot figcaption { text-align: center; color: var(--muted); font-size: 14px; margin-top: 12px; }

/* 演示视频 */
.video-box { max-width: 360px; margin: 0 auto; }
.video-box video { width: 100%; height: auto; display: block; border-radius: 28px; background: #000; border: 1px solid var(--line); box-shadow: var(--shadow); }

/* 使用条件 */
.reqs { display: grid; grid-template-columns: repeat(3, 1fr); gap: 18px; }
.req { display: flex; gap: 14px; align-items: flex-start; }
.req .dot {
  flex: none; width: 28px; height: 28px; border-radius: 50%;
  background: var(--brand); color: #fff; display: grid; place-items: center; font-weight: 700; font-size: 14px;
}
.req h3 { margin: 0 0 4px; font-size: 16px; }
.req p { margin: 0; color: var(--muted); font-size: 15px; }

.privacy-band {
  background: var(--surface); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 32px; display: flex; gap: 24px; align-items: center; box-shadow: var(--shadow);
}
.privacy-band .icon { flex: none; width: 56px; height: 56px; border-radius: 16px; background: var(--brand-soft); color: var(--ok); display: grid; place-items: center; }
.privacy-band .icon svg { width: 30px; height: 30px; }
.privacy-band h3 { margin: 0 0 4px; font-size: 20px; }
.privacy-band p { margin: 0; color: var(--muted); }

/* 文档页 */
.doc { padding: 48px 0 72px; }
.doc .wrap { max-width: 760px; }
.doc h1 { font-size: clamp(30px, 4vw, 40px); margin: 0 0 6px; letter-spacing: -.3px; }
.doc .meta { color: var(--muted); margin: 0 0 28px; }
.doc h2 { font-size: 20px; margin: 36px 0 10px; }
.doc p, .doc li { color: var(--text); }
.doc ul { padding-left: 1.2em; }
.doc li { margin: 6px 0; }
.doc .card { margin: 16px 0; }

details.faq {
  background: var(--surface); border: 1px solid var(--line); border-radius: 16px;
  padding: 4px 20px; margin: 12px 0;
}
details.faq summary { cursor: pointer; font-weight: 600; padding: 14px 0; list-style: none; display: flex; justify-content: space-between; gap: 16px; }
details.faq summary::-webkit-details-marker { display: none; }
details.faq summary::after { content: "+"; color: var(--muted); font-weight: 400; font-size: 20px; line-height: 1; }
details.faq[open] summary::after { content: "−"; }
details.faq p { margin: 0 0 16px; color: var(--muted); }

.contact {
  display: flex; align-items: center; justify-content: space-between; gap: 16px; flex-wrap: wrap;
}

/* 页脚 */
footer { border-top: 1px solid var(--line); padding: 28px 0 40px; color: var(--muted); font-size: 14px; }
footer .wrap { display: flex; justify-content: space-between; gap: 16px; flex-wrap: wrap; }
footer nav { display: flex; gap: 18px; }
footer a { color: var(--muted); }

@media (max-width: 860px) {
  .hero { padding: 44px 0 32px; }
  .hero .wrap { grid-template-columns: 1fr; gap: 36px; text-align: center; }
  .hero p.lead { margin-left: auto; margin-right: auto; }
  .cta { justify-content: center; }
  .grid, .reqs { grid-template-columns: 1fr; }
  .shots { grid-template-columns: 1fr; max-width: 320px; margin: 0 auto; }
  .privacy-band { flex-direction: column; text-align: center; }
  .nav-links { gap: 14px; font-size: 14px; }
}
@media (max-width: 480px) {
  .brand span { display: none; }
  .nav-links { gap: 12px; font-size: 13px; }
}