:root {
  --navy-950: #050d1a;
  --navy-900: #0a1830;
  --navy-800: #122a4a;
  --blue-700: #1e4f8f;
  --blue-500: #2f74c0;
  --blue-300: #6eb0ef;
  --ice: #eaf2fb;
  --cloud: #f4f8fc;
  --ink: #0d1b2a;
  --ink-muted: #3d5166;
  --gold: #d4af37;
  --gold-deep: #b8922a;
  --gold-soft: #f0d78c;
  --line: rgba(255, 255, 255, 0.14);
  --line-dark: rgba(15, 40, 70, 0.12);
  --font-display: "Noto Serif SC", "Songti SC", serif;
  --font-body: "Noto Sans SC", "PingFang SC", "Microsoft YaHei", sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
  --nav-h: 68px;
}

*,
*::before,
*::after { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: var(--font-body);
  font-size: 16px;
  line-height: 1.65;
  color: var(--ink);
  background: var(--cloud);
  -webkit-font-smoothing: antialiased;
}

img { max-width: 100%; display: block; }
a { color: inherit; text-decoration: none; }

.skip {
  position: absolute;
  left: -999px;
  top: 0;
  z-index: 100;
  background: #fff;
  padding: 8px 12px;
}
.skip:focus { left: 12px; top: 12px; }

.shell {
  width: min(1100px, calc(100% - 40px));
  margin: 0 auto;
}

/* —— Nav —— */
.nav {
  position: fixed;
  inset: 0 0 auto;
  z-index: 40;
  height: var(--nav-h);
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 16px;
  padding: 0 clamp(16px, 4vw, 36px);
  color: #fff;
  background: linear-gradient(180deg, rgba(5, 13, 26, 0.75), transparent);
  transition: background 0.35s var(--ease), border-color 0.35s, backdrop-filter 0.35s;
  border-bottom: 1px solid transparent;
}

.nav.is-solid {
  background: rgba(8, 20, 40, 0.94);
  backdrop-filter: blur(14px);
  border-bottom-color: var(--line);
}

.nav-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  font-family: var(--font-display);
  font-size: 1.15rem;
  letter-spacing: 0.06em;
  font-weight: 700;
}

.nav-brand img {
  width: 40px;
  height: 40px;
  border-radius: 10px;
  box-shadow: 0 4px 16px rgba(0, 0, 0, 0.35);
}

.nav-links {
  display: flex;
  gap: 22px;
  font-size: 0.92rem;
  font-weight: 500;
}

.nav-links a { opacity: 0.85; transition: opacity 0.2s; }
.nav-links a:hover { opacity: 1; }

.nav-btn {
  flex-shrink: 0;
  padding: 9px 16px;
  border-radius: 999px;
  background: linear-gradient(135deg, var(--gold-soft), var(--gold));
  color: var(--navy-950);
  font-size: 0.88rem;
  font-weight: 700;
}

/* —— Hero —— */
.hero {
  position: relative;
  min-height: 100svh;
  display: grid;
  place-items: center;
  color: #fff;
  overflow: hidden;
  text-align: center;
}

.hero-bg { position: absolute; inset: 0; }

.hero-bg img {
  width: 100%;
  height: 100%;
  object-fit: cover;
  transform: scale(1.05);
  animation: drift 20s var(--ease) infinite alternate;
}

.hero-shade {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(55% 50% at 50% 40%, rgba(30, 79, 143, 0.25), transparent 70%),
    linear-gradient(180deg, rgba(5, 13, 26, 0.55) 0%, rgba(5, 13, 26, 0.35) 45%, rgba(5, 13, 26, 0.88) 100%);
}

.hero-inner {
  position: relative;
  z-index: 1;
  width: min(680px, calc(100% - 40px));
  padding: calc(var(--nav-h) + 32px) 0 10vh;
  animation: rise 1.05s var(--ease) both;
}

.hero-logo {
  width: 104px;
  height: 104px;
  margin: 0 auto 22px;
  border-radius: 22px;
  box-shadow: 0 18px 50px rgba(0, 0, 0, 0.45);
}

.hero-title {
  margin: 0 0 16px;
  font-family: var(--font-display);
  font-size: clamp(2rem, 5.2vw, 3.15rem);
  font-weight: 700;
  line-height: 1.2;
  letter-spacing: 0.04em;
}

.hero-desc {
  margin: 0 auto 28px;
  max-width: 30em;
  font-size: 1.05rem;
  color: rgba(234, 242, 251, 0.88);
}

.hero-cta {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 12px;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 46px;
  padding: 0 22px;
  border-radius: 999px;
  font-weight: 700;
  font-size: 0.95rem;
  border: 1px solid transparent;
  transition: transform 0.2s var(--ease), background 0.2s, border-color 0.2s;
}

.btn:hover { transform: translateY(-1px); }

.btn-gold {
  background: linear-gradient(135deg, var(--gold-soft), var(--gold-deep));
  color: var(--navy-950);
}

.btn-line {
  border-color: rgba(255, 255, 255, 0.42);
  color: #fff;
  background: rgba(255, 255, 255, 0.06);
}

/* —— Shared section bits —— */
.block { padding: clamp(72px, 11vw, 120px) 0; }

.label {
  margin: 0 0 10px;
  font-size: 0.78rem;
  font-weight: 700;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--blue-500);
}

.h2 {
  margin: 0 0 14px;
  font-family: var(--font-display);
  font-size: clamp(1.7rem, 3.4vw, 2.4rem);
  line-height: 1.25;
  letter-spacing: 0.03em;
  font-weight: 700;
}

.lead {
  margin: 0;
  max-width: 38em;
  color: var(--ink-muted);
  font-size: 1.05rem;
}

/* Promise */
.promise {
  background:
    radial-gradient(50% 60% at 0% 0%, rgba(47, 116, 192, 0.12), transparent 55%),
    linear-gradient(180deg, #eef4fb, var(--cloud));
}

.promise-rows {
  margin-top: 40px;
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 0;
  border-top: 1px solid var(--line-dark);
}

.promise-rows article {
  padding: 28px 24px 8px 0;
  border-right: 1px solid var(--line-dark);
}

.promise-rows article:last-child {
  border-right: 0;
  padding-right: 0;
}

.promise-rows h3 {
  margin: 0 0 10px;
  font-size: 1.2rem;
  color: var(--navy-900);
}

.promise-rows p {
  margin: 0;
  color: var(--ink-muted);
  padding-right: 16px;
}

/* Guest */
.guest {
  background: var(--navy-950);
  color: var(--ice);
}

.guest .label { color: var(--gold); }
.guest .h2 { color: #fff; }
.guest .lead { color: rgba(234, 242, 251, 0.72); }

.guest-layout {
  display: grid;
  grid-template-columns: 1.05fr 0.95fr;
  gap: clamp(28px, 5vw, 56px);
  align-items: end;
}

.guest-track {
  list-style: none;
  margin: 0;
  padding: 0;
  border-left: 1px solid rgba(255, 255, 255, 0.18);
}

.guest-track li {
  padding: 18px 0 18px 22px;
  border-bottom: 1px solid rgba(255, 255, 255, 0.1);
  display: grid;
  gap: 4px;
}

.guest-track li:first-child { padding-top: 0; }
.guest-track strong {
  color: var(--gold-soft);
  font-size: 1.05rem;
}
.guest-track span {
  color: rgba(234, 242, 251, 0.72);
  font-size: 0.98rem;
}

/* Boss */
.boss {
  background: var(--cloud);
}

.boss-board {
  margin-top: 36px;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 0 40px;
}

.boss-board > div {
  padding: 24px 0;
  border-top: 1px solid var(--line-dark);
}

.boss-board h3 {
  margin: 0 0 8px;
  font-size: 1.15rem;
  color: var(--blue-700);
}

.boss-board p {
  margin: 0;
  color: var(--ink-muted);
}

/* Device */
.device {
  background:
    linear-gradient(160deg, #0e2748 0%, var(--navy-900) 55%, #0a1c38 100%);
  color: var(--ice);
}

.device .label { color: var(--blue-300); }
.device .h2 { color: #fff; }
.device .lead { color: rgba(234, 242, 251, 0.72); }

.device-layout {
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 40px;
  align-items: center;
}

.device-list {
  list-style: none;
  margin: 0;
  padding: 0;
  display: grid;
  grid-template-columns: 1fr 1fr;
  gap: 12px 16px;
}

.device-list li {
  padding: 14px 16px;
  border: 1px solid rgba(110, 176, 239, 0.28);
  background: rgba(255, 255, 255, 0.04);
  font-weight: 500;
  letter-spacing: 0.02em;
}

/* Start */
.start {
  background:
    radial-gradient(70% 80% at 80% 0%, rgba(212, 175, 55, 0.18), transparent 50%),
    linear-gradient(180deg, #102848, var(--navy-950));
  color: #fff;
  text-align: center;
}

.start .label { color: var(--gold); }
.start .h2 { color: #fff; }
.start .lead {
  margin: 0 auto 28px;
  color: rgba(234, 242, 251, 0.75);
}

.start-box img {
  margin: 0 auto 18px;
  border-radius: 16px;
  box-shadow: 0 12px 36px rgba(0, 0, 0, 0.4);
}

/* Footer */
.footer {
  background: #030910;
  color: rgba(234, 242, 251, 0.65);
  padding: 26px 0;
  font-size: 0.9rem;
}

.footer-row {
  display: flex;
  flex-wrap: wrap;
  align-items: center;
  justify-content: space-between;
  gap: 12px 20px;
}

.footer-brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
  color: #fff;
  font-family: var(--font-display);
  letter-spacing: 0.05em;
  font-weight: 700;
}

.footer-brand img { border-radius: 8px; }
.footer a:last-child { color: var(--gold-soft); }

/* Motion */
@keyframes drift {
  from { transform: scale(1.03) translate3d(0, 0, 0); }
  to { transform: scale(1.08) translate3d(-1%, -0.6%, 0); }
}

@keyframes rise {
  from { opacity: 0; transform: translate3d(0, 30px, 0); }
  to { opacity: 1; transform: none; }
}

.reveal {
  opacity: 0;
  transform: translate3d(0, 22px, 0);
  transition: opacity 0.75s var(--ease), transform 0.75s var(--ease);
}

.reveal.is-in {
  opacity: 1;
  transform: none;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
  .hero-bg img, .hero-inner, .reveal {
    animation: none !important;
    transition: none !important;
    opacity: 1 !important;
    transform: none !important;
  }
}

@media (max-width: 900px) {
  .nav-links { display: none; }
  .promise-rows { grid-template-columns: 1fr; }
  .promise-rows article {
    border-right: 0;
    border-bottom: 1px solid var(--line-dark);
    padding: 22px 0;
  }
  .guest-layout,
  .device-layout { grid-template-columns: 1fr; }
  .boss-board { grid-template-columns: 1fr; gap: 0; }
}

@media (max-width: 640px) {
  .hero-logo { width: 88px; height: 88px; border-radius: 18px; }
  .device-list { grid-template-columns: 1fr; }
  .footer-row { flex-direction: column; align-items: flex-start; }
}