:root {
  --bg: #f5f7fb;
  --surface: #ffffff;
  --surface-2: #eef3fb;
  --text: #0f172a;
  --muted: #64748b;
  --line: #dbe4f0;
  --blue: #155eef;
  --blue-dark: #0b3aa4;
  --blue-soft: #eaf1ff;
  --green: #138a5b;
  --amber: #a15c00;
  --shadow: 0 18px 48px rgba(15, 23, 42, .08);
  --radius: 22px;
  --max: 1180px;
}
* { box-sizing: border-box; }
html { scroll-behavior: smooth; }
body {
  margin: 0;
  font-family: Inter, ui-sans-serif, system-ui, -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.65;
}
a { color: inherit; text-decoration: none; }
img { max-width: 100%; display: block; }
button, a { -webkit-tap-highlight-color: transparent; }
.container { width: min(calc(100% - 36px), var(--max)); margin: 0 auto; }
.topbar {
  position: sticky; top: 0; z-index: 20;
  backdrop-filter: blur(16px);
  background: rgba(245,247,251,.86);
  border-bottom: 1px solid rgba(219,228,240,.8);
}
.nav { height: 68px; display:flex; align-items:center; justify-content:space-between; gap:20px; }
.brand { display:flex; align-items:center; gap:12px; font-weight:800; letter-spacing:-.02em; }
.brand-mark { width:38px; height:38px; border-radius:12px; display:grid; place-items:center; color:white; background:linear-gradient(145deg,#0b3aa4,#2e72ff); font-size:14px; box-shadow:0 8px 24px rgba(21,94,239,.24); }
.brand small { display:block; color:var(--muted); font-size:11px; font-weight:700; letter-spacing:.08em; text-transform:uppercase; margin-top:-3px; }
.nav-links { display:flex; align-items:center; gap:6px; color:#334155; font-size:14px; font-weight:650; }
.nav-links a { padding:9px 12px; border-radius:10px; }
.nav-links a:hover { background:#fff; color:var(--blue); }
.hero { padding:82px 0 56px; }
.eyebrow { display:inline-flex; gap:8px; align-items:center; padding:7px 10px; border:1px solid #c9d8f7; border-radius:999px; color:var(--blue-dark); background:rgba(234,241,255,.75); font-size:13px; font-weight:750; }
.dot { width:7px; height:7px; background:#2e72ff; border-radius:50%; }
h1 { font-size:clamp(42px,7vw,82px); line-height:1.02; letter-spacing:-.055em; margin:22px 0 22px; max-width:950px; }
.hero h1 span { color:var(--blue); }
.hero-copy { display:grid; grid-template-columns:1.35fr .65fr; gap:42px; align-items:end; }
.hero p { margin:0; max-width:720px; color:#475569; font-size:clamp(17px,2vw,21px); }
.hero-actions { display:flex; gap:11px; flex-wrap:wrap; margin-top:28px; }
.btn { display:inline-flex; align-items:center; justify-content:center; gap:9px; min-height:46px; padding:0 17px; border-radius:12px; font-weight:750; font-size:14px; border:1px solid transparent; transition:.18s ease; }
.btn-primary { background:var(--blue); color:#fff; box-shadow:0 10px 26px rgba(21,94,239,.22); }
.btn-primary:hover { transform:translateY(-1px); background:#0f4fd1; }
.btn-secondary { background:#fff; border-color:var(--line); color:#24324a; }
.btn-secondary:hover { border-color:#b8c8df; transform:translateY(-1px); }
.hero-note { background:var(--surface); border:1px solid var(--line); box-shadow:var(--shadow); border-radius:var(--radius); padding:22px; }
.hero-note .label { color:var(--muted); font-size:12px; text-transform:uppercase; letter-spacing:.08em; font-weight:800; }
.hero-note strong { display:block; font-size:18px; margin:4px 0; }
.hero-note p { font-size:13px; color:var(--muted); }
.section { padding:48px 0; }
.section-head { display:flex; align-items:end; justify-content:space-between; gap:24px; margin-bottom:24px; }
.section-head h2 { margin:0; font-size:30px; letter-spacing:-.035em; }
.section-head p { margin:0; color:var(--muted); font-size:14px; max-width:520px; }
.grid-4 { display:grid; grid-template-columns:repeat(4,1fr); gap:16px; }
.card { background:var(--surface); border:1px solid var(--line); border-radius:18px; padding:22px; box-shadow:0 8px 28px rgba(15,23,42,.04); }
.card .icon { width:42px; height:42px; border-radius:13px; display:grid; place-items:center; background:var(--blue-soft); color:var(--blue); font-weight:900; margin-bottom:26px; }
.card h3 { margin:0 0 7px; font-size:18px; letter-spacing:-.02em; }
.card p { margin:0; color:var(--muted); font-size:14px; }
.card.disabled { opacity:.72; }
.card .tag { display:inline-flex; margin-top:15px; color:var(--blue-dark); background:#f0f5ff; border:1px solid #d6e2fb; border-radius:999px; padding:4px 8px; font-size:11px; font-weight:800; }
.feature { display:grid; grid-template-columns:1.05fr .95fr; gap:0; overflow:hidden; border-radius:26px; background:#0c1f46; color:#fff; box-shadow:0 24px 56px rgba(15,23,42,.18); }
.feature-copy { padding:46px; display:flex; flex-direction:column; justify-content:center; }
.feature-copy .kicker { color:#9fc1ff; font-weight:800; font-size:13px; letter-spacing:.04em; }
.feature-copy h2 { margin:9px 0 14px; font-size:38px; line-height:1.12; letter-spacing:-.045em; }
.feature-copy p { margin:0; color:#cbd8ee; font-size:16px; max-width:560px; }
.feature-copy .btn { margin-top:24px; align-self:flex-start; background:#fff; color:#0c1f46; }
.feature-media { min-height:410px; background:#e9eef9; padding:20px; display:grid; place-items:center; }
.feature-media img { border-radius:14px; box-shadow:0 18px 40px rgba(3,10,24,.18); }
.timeline { display:grid; grid-template-columns:repeat(3,1fr); gap:16px; }
.timeline .card { min-height:190px; }
.timeline .num { color:var(--blue); font-weight:900; font-size:12px; letter-spacing:.09em; }
.footer { margin-top:70px; padding:34px 0 46px; border-top:1px solid var(--line); color:var(--muted); font-size:13px; }
.footer-inner { display:flex; justify-content:space-between; align-items:center; gap:20px; }

/* Tutorial */
.doc-hero { padding:60px 0 30px; }
.breadcrumb { color:var(--muted); font-size:13px; margin-bottom:18px; }
.breadcrumb a:hover { color:var(--blue); }
.doc-hero h1 { font-size:clamp(38px,6vw,64px); margin:0 0 16px; max-width:960px; }
.doc-lead { color:#526178; max-width:820px; font-size:18px; margin:0; }
.meta { display:flex; gap:10px; flex-wrap:wrap; margin-top:20px; }
.meta span { font-size:12px; color:#334155; background:#fff; border:1px solid var(--line); padding:6px 9px; border-radius:999px; }
.infographic { margin:28px auto 46px; background:#fff; padding:10px; border:1px solid var(--line); border-radius:20px; box-shadow:var(--shadow); }
.infographic img { width:100%; border-radius:12px; }
.doc-layout { display:grid; grid-template-columns:230px minmax(0,760px); gap:54px; align-items:start; justify-content:center; }
.toc { position:sticky; top:92px; padding:14px 0; }
.toc-title { font-size:12px; color:#94a3b8; font-weight:850; text-transform:uppercase; letter-spacing:.09em; margin:0 0 9px 10px; }
.toc a { display:block; padding:8px 10px; border-radius:9px; color:#64748b; font-size:13px; font-weight:650; }
.toc a:hover { color:var(--blue); background:#eef4ff; }
.article { min-width:0; }
.article section { scroll-margin-top:100px; padding:0 0 38px; }
.article h2 { margin:0 0 15px; font-size:28px; letter-spacing:-.035em; }
.article h3 { margin:24px 0 8px; font-size:18px; }
.article p, .article li { color:#45546a; }
.article ul, .article ol { padding-left:22px; }
.step { display:grid; grid-template-columns:46px 1fr; gap:16px; margin:18px 0; }
.step-no { width:42px; height:42px; border-radius:14px; background:var(--blue); color:#fff; display:grid; place-items:center; font-weight:900; box-shadow:0 8px 18px rgba(21,94,239,.2); }
.step-body { border:1px solid var(--line); background:#fff; border-radius:16px; padding:18px 20px; }
.step-body h3 { margin:0 0 8px; }
.code { background:#0b1220; color:#dbeafe; border-radius:13px; padding:15px 17px; overflow:auto; font:13px/1.6 ui-monospace,SFMono-Regular,Menlo,Consolas,monospace; margin:12px 0; white-space:pre-wrap; }
.copyline { display:flex; align-items:center; justify-content:space-between; gap:12px; padding:11px 13px; border-radius:12px; border:1px solid #cfe0ff; background:#f3f7ff; margin:10px 0; }
.copyline code { color:#12376e; overflow-wrap:anywhere; font-size:13px; }
.notice { border-radius:14px; padding:15px 17px; margin:17px 0; background:#fff8e8; border:1px solid #f0d9a4; color:#724400; font-size:14px; }
.success { background:#eefbf5; border-color:#b9ead2; color:#0f6846; }
.prompt { background:#fff; border:1px solid var(--line); border-left:4px solid var(--blue); border-radius:11px; padding:14px 15px; margin:10px 0; color:#334155; font-size:14px; }
.flow { display:flex; align-items:center; flex-wrap:wrap; gap:7px; margin-top:12px; }
.flow span { background:#eef4ff; color:#174893; border:1px solid #d7e4fb; padding:6px 9px; border-radius:9px; font-size:12px; font-weight:750; }
.flow b { color:#8ba0bd; }
.ref { font-size:13px; color:var(--muted); }
.ref a { color:var(--blue); text-decoration:underline; text-underline-offset:3px; }
@media (max-width: 900px) {
  .nav-links { display:none; }
  .hero { padding-top:56px; }
  .hero-copy, .feature, .doc-layout { grid-template-columns:1fr; }
  .hero-note { margin-top:20px; }
  .grid-4 { grid-template-columns:1fr 1fr; }
  .timeline { grid-template-columns:1fr; }
  .feature-media { min-height:auto; }
  .toc { display:none; }
  .doc-layout { justify-content:stretch; }
}
@media (max-width: 620px) {
  .container { width:min(calc(100% - 24px),var(--max)); }
  .grid-4 { grid-template-columns:1fr; }
  .hero { padding-top:42px; }
  .hero h1 { font-size:48px; }
  .feature-copy { padding:30px 24px; }
  .feature-copy h2 { font-size:31px; }
  .feature-media { padding:12px; }
  .footer-inner { flex-direction:column; align-items:flex-start; }
  .step { grid-template-columns:38px 1fr; gap:10px; }
  .step-no { width:36px; height:36px; border-radius:11px; }
  .step-body { padding:15px; }
}