:root {
  --ink: #0f172a;
  --muted: #64748b;
  --line: #e2e8f0;
  --soft: #f8fafc;
  --blue: #2563eb;
  --card: #ffffff;
  --shadow: 0 20px 50px rgb(15 23 42 / 8%);
  --header: 72px;
  --wrap: 1120px;
}

* { box-sizing: border-box; }
html { scroll-behavior: smooth; scroll-padding-top: 88px; }
body {
  margin: 0;
  color: var(--ink);
  background: #fff;
  font-family: "Segoe UI", "PingFang SC", "Microsoft YaHei", sans-serif;
  line-height: 1.65;
}
a { color: inherit; }
.skip { position: absolute; left: 12px; top: -40px; background: #fff; padding: 6px 10px; }
.skip:focus { top: 8px; }
.wrap { width: min(var(--wrap), calc(100% - 40px)); margin: 0 auto; }

.header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  gap: 28px;
  height: var(--header);
  padding: 0 22px;
  background: rgb(255 255 255 / 86%);
  backdrop-filter: blur(16px);
  border-bottom: 1px solid transparent;
  transition: box-shadow .2s ease, border-color .2s ease;
}
.header.is-stuck { border-color: var(--line); box-shadow: 0 8px 24px rgb(15 23 42 / 6%); }
.brand { display: flex; align-items: center; gap: 10px; text-decoration: none; }
.brand span { display: flex; flex-direction: column; line-height: 1.1; }
.brand small { color: var(--blue); font-size: 12px; }
.nav { display: flex; gap: 22px; }
.nav a { color: #475569; text-decoration: none; font-size: 14px; font-weight: 600; }
.nav a:hover, .nav a.is-on { color: var(--ink); }
.header__actions { margin-left: auto; display: flex; align-items: center; gap: 10px; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 42px;
  padding: 0 18px;
  border-radius: 999px;
  text-decoration: none;
  font-weight: 650;
  font-size: 14px;
  border: 1px solid transparent;
  transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
}
.btn:hover { transform: translateY(-1px); }
.btn--enter, .btn--dark { background: #0f172a; color: #fff; box-shadow: 0 8px 18px rgb(15 23 42 / 16%); }
.btn--enter::after { content: " →"; }
.btn--line { background: #fff; border-color: #cbd5e1; color: var(--ink); }
.nav-toggle { display: none; width: 42px; height: 42px; border: 1px solid var(--line); border-radius: 12px; background: #fff; }
.nav-toggle span { display: block; width: 16px; height: 1.5px; margin: 4px auto; background: var(--ink); }

.hero { position: relative; overflow: hidden; padding: 72px 0 36px; text-align: center; }
.blob { position: absolute; border-radius: 50%; filter: blur(40px); pointer-events: none; }
.blob--a { width: 420px; height: 280px; left: 8%; top: 40px; background: rgb(37 99 235 / 18%); }
.blob--b { width: 360px; height: 240px; right: 6%; top: 120px; background: rgb(34 211 238 / 28%); }
.hero__inner { position: relative; }
.pill {
  display: inline-flex;
  margin: 0 0 18px;
  padding: 6px 12px;
  border-radius: 999px;
  background: #eff6ff;
  color: #1d4ed8;
  font-size: 13px;
  font-weight: 650;
}
h1, h2, h3 { letter-spacing: -0.03em; line-height: 1.2; }
h1 { margin: 0; font-size: clamp(40px, 6vw, 68px); font-weight: 760; }
h2 { margin: 0; font-size: clamp(28px, 3vw, 40px); }
.lead { max-width: 680px; margin: 18px auto 0; color: var(--muted); font-size: 18px; }
.hero__actions { display: flex; justify-content: center; gap: 12px; margin-top: 28px; }

.mock {
  margin: 48px auto 0;
  max-width: 760px;
  text-align: left;
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 20px;
  box-shadow: var(--shadow);
  overflow: hidden;
}
.mock__bar { display: flex; align-items: center; gap: 6px; padding: 12px 16px; background: #f8fafc; border-bottom: 1px solid var(--line); }
.mock__bar i { width: 10px; height: 10px; border-radius: 50%; background: #e2e8f0; }
.mock__bar i:first-child { background: #fb7185; }
.mock__bar i:nth-child(2) { background: #fbbf24; }
.mock__bar i:nth-child(3) { background: #34d399; }
.mock__bar span { margin-left: 8px; color: #94a3b8; font-size: 12px; }
.mock__tabs { display: flex; gap: 8px; padding: 14px 16px 0; }
.mock__tabs button {
  border: 0;
  background: #f1f5f9;
  color: #475569;
  border-radius: 999px;
  padding: 8px 14px;
  font-weight: 650;
  cursor: pointer;
}
.mock__tabs button.is-on { background: #0f172a; color: #fff; }
.mock__panel { padding: 8px 20px 20px; }
.mock__panel h3 { margin: 12px 0; font-size: 18px; }
.mock__panel ul { list-style: none; margin: 0; padding: 0; }
.mock__panel li { display: flex; justify-content: space-between; gap: 16px; padding: 12px 0; border-top: 1px solid var(--line); }
.mock__panel span { color: var(--muted); }

.stats { border-block: 1px solid var(--line); }
.stats__row { display: grid; grid-template-columns: repeat(4, 1fr); }
.stats__row div { padding: 22px 8px; text-align: center; }
.stats__row strong { display: block; font-size: 26px; }
.stats__row span { color: var(--muted); font-size: 13px; }

.section { padding: 84px 0; }
.section--soft { background: linear-gradient(180deg, #f8fafc, #fff); }
.section__head { max-width: 680px; margin-bottom: 28px; }
.section__head p:last-child { color: var(--muted); }
.eyebrow { margin: 0 0 8px; color: var(--blue); font-size: 13px; font-weight: 700; letter-spacing: 0.08em; }
.grid { display: grid; gap: 16px; }
.grid--4 { grid-template-columns: repeat(4, 1fr); }
.grid--3 { grid-template-columns: repeat(3, 1fr); }
.grid--5 { grid-template-columns: repeat(5, 1fr); margin-top: 18px; }
.card {
  padding: 22px;
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 18px;
  box-shadow: 0 1px 2px rgb(15 23 42 / 4%);
  transition: transform .2s ease, box-shadow .2s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow); }
.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p, .prose, .note { color: var(--muted); }
.card p { margin: 0; }
.card--flat:hover { transform: none; }
.tag { margin: 0 0 8px; color: var(--blue); font-size: 13px; font-weight: 700; }

.steps, .flow { display: grid; gap: 16px; margin: 0; padding: 0; list-style: none; }
.steps { grid-template-columns: repeat(3, 1fr); }
.steps li, .flow li { padding: 8px 8px 0 0; }
.steps span { color: var(--blue); font-weight: 800; }
.steps p, .flow span { color: var(--muted); }
.flow { grid-template-columns: repeat(6, 1fr); margin-top: 28px; }
.flow li { padding: 16px; border-radius: 16px; background: #eff6ff; }
.flow b, .flow span { display: block; }
.flow span { margin-top: 6px; font-size: 13px; }

.split { display: grid; grid-template-columns: 1.1fr .9fr; gap: 48px; align-items: start; }
.ticks { margin: 16px 0 0; padding: 0; list-style: none; }
.ticks li { position: relative; padding: 8px 0 8px 18px; color: #334155; }
.ticks li::before { content: ""; position: absolute; left: 0; top: 16px; width: 8px; height: 8px; border-radius: 50%; background: var(--blue); }
.layers { display: grid; gap: 10px; margin-top: 18px; }
.layers div { display: flex; justify-content: space-between; gap: 12px; padding: 14px 16px; border-radius: 14px; background: var(--soft); }
.layers span { color: var(--muted); }
.accordion details { border-bottom: 1px solid var(--line); }
.accordion summary { cursor: pointer; padding: 16px 0; font-weight: 750; font-size: 18px; }
.accordion p { margin: 0 0 16px; color: var(--muted); }
.quote { margin: 28px 0 0; font-size: 22px; letter-spacing: -0.03em; }
.roles { display: grid; grid-template-columns: repeat(3, 1fr); gap: 16px; margin-top: 16px; }
.roles article { padding: 18px 0 0; border-top: 2px solid var(--blue); }
.roles h3 { margin: 0 0 6px; }
.roles p { margin: 0; color: var(--muted); }
.note { margin-top: 18px; }
.contact { list-style: none; margin: 18px 0 0; padding: 0; }
.contact li { display: grid; grid-template-columns: 52px 1fr; gap: 8px; padding: 10px 0; border-top: 1px solid var(--line); }
.contact a { color: var(--blue); }
.prose { margin: 0 0 12px; }

.cta { padding: 10px 0 72px; }
.cta__box {
  display: flex;
  justify-content: space-between;
  align-items: center;
  gap: 24px;
  padding: 36px;
  border-radius: 28px;
  background: linear-gradient(135deg, #eff6ff, #fff 42%, #ecfeff);
  border: 1px solid #dbeafe;
}
.cta__box h2 { font-size: 32px; }
.cta__box p { margin: 8px 0 0; color: var(--muted); }
.footer { border-top: 1px solid var(--line); padding: 22px 0 32px; }
.footer__row { display: flex; justify-content: space-between; gap: 16px; color: var(--muted); font-size: 14px; }
.footer a { color: var(--blue); font-weight: 700; }

.reveal { opacity: 0; transform: translateY(16px); animation: rise .7s ease forwards; }
.reveal:nth-child(2) { animation-delay: .08s; }
.reveal:nth-child(3) { animation-delay: .16s; }
@keyframes rise { to { opacity: 1; transform: none; } }

@media (max-width: 980px) {
  .stats__row, .grid--4, .grid--5, .flow { grid-template-columns: 1fr 1fr; }
  .grid--3, .steps, .split, .roles { grid-template-columns: 1fr; }
}
@media (max-width: 760px) {
  .nav-toggle { display: inline-block; }
  .nav {
    display: none;
    position: absolute;
    left: 0; right: 0; top: var(--header);
    flex-direction: column;
    gap: 0;
    padding: 8px 18px 16px;
    background: #fff;
    border-bottom: 1px solid var(--line);
  }
  .nav.is-open { display: flex; }
  .nav a { padding: 12px 0; }
  .stats__row, .grid--4, .grid--5, .flow, .footer__row, .cta__box { grid-template-columns: 1fr; display: grid; }
  .footer__row, .cta__box { display: flex; flex-direction: column; align-items: flex-start; }
  .hero { padding-top: 36px; }
  .mock__panel li { flex-direction: column; gap: 4px; }
}
@media (prefers-reduced-motion: reduce) {
  .reveal { animation: none; opacity: 1; transform: none; }
  .btn, .card { transition: none; }
}