:root {
  --bg-deep: #020814;
  --bg-mid: #071428;
  --cyan: #3ad7ff;
  --cyan-soft: rgba(58, 215, 255, 0.18);
  --amber: #f0a35a;
  --text: #eef7ff;
  --text-muted: rgba(238, 247, 255, 0.68);
  --line: rgba(58, 215, 255, 0.22);
  --glass: rgba(6, 18, 36, 0.55);
  --font-brand: "ZCOOL QingKe HuangYou", "Outfit", sans-serif;
  --font-display: "Orbitron", "Outfit", sans-serif;
  --font-body: "Outfit", "PingFang SC", "Microsoft YaHei", sans-serif;
  --ease: cubic-bezier(0.22, 1, 0.36, 1);
}

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

html {
  scroll-behavior: smooth;
}

body {
  margin: 0;
  min-height: 100vh;
  color: var(--text);
  font-family: var(--font-body);
  font-weight: 400;
  background: var(--bg-deep);
  line-height: 1.6;
  overflow-x: hidden;
}

a {
  color: inherit;
  text-decoration: none;
}

img {
  max-width: 100%;
  display: block;
}

.noise {
  pointer-events: none;
  position: fixed;
  inset: 0;
  z-index: 80;
  opacity: 0.035;
  background-image: url("data:image/svg+xml,%3Csvg viewBox='0 0 200 200' xmlns='http://www.w3.org/2000/svg'%3E%3Cfilter id='n'%3E%3CfeTurbulence type='fractalNoise' baseFrequency='0.85' numOctaves='4' stitchTiles='stitch'/%3E%3C/filter%3E%3Crect width='100%25' height='100%25' filter='url(%23n)'/%3E%3C/svg%3E");
}

/* Header */
.site-header {
  position: fixed;
  top: 0;
  left: 0;
  right: 0;
  z-index: 50;
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 1.1rem clamp(1.25rem, 4vw, 3rem);
  background: linear-gradient(180deg, rgba(2, 8, 20, 0.72), rgba(2, 8, 20, 0));
  backdrop-filter: blur(10px);
  transition: background 0.4s var(--ease), border-color 0.4s var(--ease);
  border-bottom: 1px solid transparent;
}

.site-header.is-scrolled {
  background: rgba(2, 8, 20, 0.82);
  border-bottom-color: var(--line);
}

.logo {
  font-family: var(--font-brand);
  font-size: 1.35rem;
  letter-spacing: 0.08em;
  color: var(--text);
}

.nav {
  display: flex;
  align-items: center;
  gap: 1.75rem;
}

.nav a {
  font-size: 0.92rem;
  font-weight: 400;
  color: var(--text-muted);
  transition: color 0.25s var(--ease);
}

.nav a:hover {
  color: var(--cyan);
}

.nav-cta {
  padding: 0.45rem 1rem;
  border: 1px solid var(--line);
  color: var(--text) !important;
  background: var(--cyan-soft);
  transition: border-color 0.25s var(--ease), background 0.25s var(--ease);
}

.nav-cta:hover {
  border-color: var(--cyan);
  background: rgba(58, 215, 255, 0.28);
}

.menu-btn {
  display: none;
  width: 2.5rem;
  height: 2.5rem;
  border: 1px solid var(--line);
  background: var(--glass);
  cursor: pointer;
  padding: 0;
  align-items: center;
  justify-content: center;
  flex-direction: column;
  gap: 6px;
}

.menu-btn span {
  display: block;
  width: 1rem;
  height: 1.5px;
  background: var(--text);
  transition: transform 0.3s var(--ease);
}

.mobile-nav {
  position: fixed;
  top: 4.2rem;
  right: 1rem;
  z-index: 49;
  display: flex;
  flex-direction: column;
  gap: 0.25rem;
  padding: 0.75rem;
  min-width: 10rem;
  background: rgba(4, 14, 30, 0.94);
  border: 1px solid var(--line);
  backdrop-filter: blur(16px);
}

.mobile-nav[hidden] {
  display: none;
}

.mobile-nav a {
  padding: 0.7rem 0.9rem;
  color: var(--text-muted);
}

.mobile-nav a:hover {
  color: var(--cyan);
}

/* Hero */
.hero {
  position: relative;
  min-height: 100svh;
  display: grid;
  place-items: center;
  overflow: hidden;
}

.hero-bg {
  position: absolute;
  inset: 0;
  background:
    url("../assets/hero-bg.png") center / cover no-repeat;
  transform: scale(1.04);
  animation: hero-drift 28s ease-in-out infinite alternate;
}

.hero-veil {
  position: absolute;
  inset: 0;
  background:
    radial-gradient(ellipse 48% 42% at 50% 42%, rgba(2, 8, 20, 0.72) 0%, rgba(2, 8, 20, 0.42) 42%, rgba(2, 8, 20, 0.2) 68%, transparent 100%),
    radial-gradient(ellipse 80% 70% at 50% 50%, rgba(2, 8, 20, 0.2) 0%, rgba(2, 8, 20, 0.62) 70%, rgba(2, 8, 20, 0.92) 100%),
    linear-gradient(180deg, rgba(2, 8, 20, 0.45) 0%, transparent 22%, transparent 70%, rgba(2, 8, 20, 0.95) 100%);
}

.hero-content {
  position: relative;
  z-index: 2;
  width: min(920px, calc(100% - 2.5rem));
  text-align: center;
  padding: 5.5rem 1.25rem 5rem;
  margin-top: -6vh;
}

.brand {
  margin: 0 0 1.35rem;
  font-family: var(--font-brand);
  font-size: clamp(2.15rem, 5.8vw, 3.7rem);
  line-height: 1.18;
  letter-spacing: 0.06em;
  color: #fff;
  text-shadow:
    0 2px 24px rgba(2, 8, 20, 0.9),
    0 0 48px rgba(2, 8, 20, 0.75),
    0 0 2px rgba(2, 8, 20, 0.8);
  opacity: 0;
  animation: rise 1s var(--ease) 0.15s forwards;
}

.hero h1 {
  margin: 0 0 1rem;
  font-family: var(--font-body);
  font-weight: 500;
  font-size: clamp(1.15rem, 2.4vw, 1.65rem);
  letter-spacing: 0.12em;
  color: #f2f8ff;
  text-shadow: 0 2px 18px rgba(2, 8, 20, 0.85);
  opacity: 0;
  animation: rise 1s var(--ease) 0.35s forwards;
}

.lead {
  margin: 0 auto 2rem;
  max-width: 34rem;
  font-size: clamp(0.95rem, 1.5vw, 1.08rem);
  font-weight: 300;
  color: rgba(220, 236, 255, 0.88);
  text-shadow: 0 2px 14px rgba(2, 8, 20, 0.8);
  opacity: 0;
  animation: rise 1s var(--ease) 0.5s forwards;
}

.cta-group {
  display: flex;
  flex-wrap: wrap;
  gap: 0.85rem;
  justify-content: center;
  opacity: 0;
  animation: rise 1s var(--ease) 0.65s forwards;
}

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  min-height: 2.85rem;
  padding: 0.7rem 1.45rem;
  font-size: 0.95rem;
  font-weight: 500;
  letter-spacing: 0.04em;
  border: 1px solid transparent;
  transition: transform 0.25s var(--ease), background 0.25s var(--ease), border-color 0.25s var(--ease), box-shadow 0.25s var(--ease);
}

.btn:hover {
  transform: translateY(-2px);
}

.btn-primary {
  background: linear-gradient(135deg, #2ec8f5, #1a8fd4);
  color: #041018;
  box-shadow: 0 0 0 1px rgba(58, 215, 255, 0.25);
}

.btn-primary:hover {
  box-shadow: 0 8px 28px rgba(46, 200, 245, 0.28);
}

.btn-ghost {
  border-color: var(--line);
  background: rgba(4, 14, 30, 0.45);
  color: var(--text);
  backdrop-filter: blur(8px);
}

.btn-ghost:hover {
  border-color: var(--cyan);
  background: var(--cyan-soft);
}

.scroll-hint {
  position: absolute;
  bottom: 1.6rem;
  left: 50%;
  transform: translateX(-50%);
  z-index: 2;
  display: flex;
  flex-direction: column;
  align-items: center;
  gap: 0.55rem;
  color: var(--text-muted);
  font-size: 0.72rem;
  letter-spacing: 0.18em;
  opacity: 0;
  animation: rise 1s var(--ease) 1s forwards;
}

.scroll-hint i {
  width: 1px;
  height: 2.2rem;
  background: linear-gradient(180deg, var(--cyan), transparent);
  animation: pulse-line 2.2s ease-in-out infinite;
}

/* Sections */
.section {
  position: relative;
  padding: clamp(4.5rem, 10vw, 7.5rem) 0;
}

.section-inner {
  width: min(980px, calc(100% - 2.5rem));
  margin: 0 auto;
}

.eyebrow {
  margin: 0 0 0.75rem;
  font-family: var(--font-display);
  font-size: 0.72rem;
  font-weight: 500;
  letter-spacing: 0.28em;
  text-transform: uppercase;
  color: var(--cyan);
}

.section h2 {
  margin: 0 0 1rem;
  font-family: var(--font-brand);
  font-size: clamp(1.85rem, 4vw, 2.6rem);
  font-weight: 400;
  letter-spacing: 0.04em;
  line-height: 1.25;
}

.section-desc {
  margin: 0;
  max-width: 36rem;
  color: var(--text-muted);
  font-weight: 300;
  font-size: 1.02rem;
}

.services {
  background:
    linear-gradient(180deg, var(--bg-deep) 0%, var(--bg-mid) 40%, var(--bg-deep) 100%);
}

.service-list {
  list-style: none;
  margin: 3rem 0 0;
  padding: 0;
  border-top: 1px solid var(--line);
}

.service-list li {
  display: grid;
  grid-template-columns: 4.5rem 1fr;
  gap: 1.25rem;
  padding: 1.65rem 0;
  border-bottom: 1px solid var(--line);
  opacity: 0;
  transform: translateY(18px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.service-list li.is-visible {
  opacity: 1;
  transform: none;
}

.svc-index {
  font-family: var(--font-display);
  font-size: 0.85rem;
  letter-spacing: 0.12em;
  color: var(--cyan);
  padding-top: 0.35rem;
}

.service-list h3 {
  margin: 0 0 0.45rem;
  font-size: 1.2rem;
  font-weight: 500;
  letter-spacing: 0.03em;
}

.service-list p {
  margin: 0;
  color: var(--text-muted);
  font-weight: 300;
  max-width: 34rem;
}

.about {
  background:
    radial-gradient(ellipse 70% 60% at 80% 20%, rgba(58, 215, 255, 0.08), transparent 55%),
    var(--bg-deep);
}

.about-grid {
  display: grid;
  grid-template-columns: 1.15fr 0.85fr;
  gap: clamp(2rem, 6vw, 4rem);
  align-items: end;
}

.facts {
  margin: 0;
  display: flex;
  flex-direction: column;
  gap: 1.4rem;
  padding-left: 1.5rem;
  border-left: 1px solid var(--line);
}

.facts div {
  opacity: 0;
  transform: translateY(14px);
  transition: opacity 0.7s var(--ease), transform 0.7s var(--ease);
}

.facts div.is-visible {
  opacity: 1;
  transform: none;
}

.facts dt {
  font-family: var(--font-display);
  font-size: 0.68rem;
  letter-spacing: 0.2em;
  text-transform: uppercase;
  color: var(--amber);
  margin-bottom: 0.35rem;
}

.facts dd {
  margin: 0;
  font-size: 1.05rem;
  font-weight: 400;
}

.contact {
  padding-bottom: clamp(5rem, 12vw, 8rem);
}

.contact-panel {
  text-align: center;
  padding: clamp(2.5rem, 6vw, 4rem) 1.5rem;
  background:
    linear-gradient(160deg, rgba(10, 28, 52, 0.85), rgba(4, 14, 30, 0.7)),
    radial-gradient(ellipse at 50% 0%, rgba(58, 215, 255, 0.12), transparent 60%);
  border: 1px solid var(--line);
  backdrop-filter: blur(12px);
}

.contact-panel .section-desc {
  margin: 0 auto 1.75rem;
}

.contact-meta {
  margin: 1.5rem 0 0;
  font-size: 0.88rem;
  color: var(--text-muted);
  letter-spacing: 0.04em;
}

.site-footer {
  display: flex;
  flex-wrap: wrap;
  justify-content: space-between;
  align-items: center;
  gap: 0.75rem 1.25rem;
  padding: 1.4rem clamp(1.25rem, 4vw, 3rem) 2rem;
  border-top: 1px solid var(--line);
  color: var(--text-muted);
  font-size: 0.85rem;
}

.footer-beian {
  display: flex;
  flex-wrap: wrap;
  justify-content: center;
  gap: 0.65rem 1.25rem;
}

.site-footer .beian {
  color: var(--text-muted);
  transition: color 0.25s var(--ease);
}

.site-footer .beian:hover {
  color: var(--cyan);
}

.footer-en {
  font-family: var(--font-display);
  font-size: 0.72rem;
  letter-spacing: 0.14em;
  text-transform: uppercase;
}

@keyframes rise {
  from {
    opacity: 0;
    transform: translateY(22px);
  }
  to {
    opacity: 1;
    transform: none;
  }
}

@keyframes hero-drift {
  from {
    transform: scale(1.04) translate3d(0, 0, 0);
  }
  to {
    transform: scale(1.08) translate3d(0, -1.2%, 0);
  }
}

@keyframes pulse-line {
  0%,
  100% {
    opacity: 0.35;
    transform: scaleY(0.7);
    transform-origin: top;
  }
  50% {
    opacity: 1;
    transform: scaleY(1);
    transform-origin: top;
  }
}

@media (max-width: 820px) {
  .nav {
    display: none;
  }

  .menu-btn {
    display: inline-flex;
  }

  .about-grid {
    grid-template-columns: 1fr;
  }

  .facts {
    padding-left: 0;
    border-left: none;
    border-top: 1px solid var(--line);
    padding-top: 1.5rem;
  }

  .service-list li {
    grid-template-columns: 3rem 1fr;
    gap: 0.85rem;
  }
}

@media (max-width: 520px) {
  .brand {
    letter-spacing: 0.03em;
  }

  .hero h1 {
    letter-spacing: 0.06em;
  }

  .cta-group {
    flex-direction: column;
    align-items: stretch;
  }

  .btn {
    width: 100%;
  }

  .site-footer {
    flex-direction: column;
    align-items: flex-start;
  }
}

@media (prefers-reduced-motion: reduce) {
  html {
    scroll-behavior: auto;
  }

  .hero-bg,
  .scroll-hint i,
  .brand,
  .hero h1,
  .lead,
  .cta-group,
  .scroll-hint {
    animation: none !important;
    opacity: 1;
    transform: none;
  }

  .service-list li,
  .facts div {
    opacity: 1;
    transform: none;
  }
}