:root {
  --bg: #070b16;
  --bg-soft: #0c1222;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-strong: rgba(255, 255, 255, 0.07);
  --border: rgba(255, 255, 255, 0.09);
  --text: #e8ecf4;
  --text-muted: #9aa7bd;
  --text-dim: #6b768c;
  --cyan: #22d3ee;
  --blue: #6366f1;
  --violet: #a855f7;
  --grad: linear-gradient(120deg, #22d3ee 0%, #6366f1 48%, #a855f7 100%);
  --radius: 18px;
  --maxw: 1180px;
  --shadow: 0 24px 60px rgba(0, 0, 0, 0.45);
}

* { margin: 0; padding: 0; box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "PingFang SC", "Hiragino Sans GB",
    "Microsoft YaHei", "Helvetica Neue", Arial, sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  overflow-x: hidden;
}

a { color: inherit; text-decoration: none; }
ul { list-style: none; }
img, svg { display: block; }

.container {
  width: 100%;
  max-width: var(--maxw);
  margin: 0 auto;
  padding: 0 24px;
}

/* 背景光晕 */
.bg-aurora {
  position: fixed;
  inset: 0;
  z-index: -2;
  background:
    radial-gradient(900px 500px at 12% -8%, rgba(99, 102, 241, 0.22), transparent 60%),
    radial-gradient(800px 520px at 90% 8%, rgba(168, 85, 247, 0.18), transparent 60%),
    radial-gradient(700px 500px at 50% 110%, rgba(34, 211, 238, 0.14), transparent 60%);
  pointer-events: none;
}

/* Header */
.site-header {
  position: fixed;
  top: 0; left: 0; right: 0;
  z-index: 50;
  backdrop-filter: blur(14px);
  -webkit-backdrop-filter: blur(14px);
  background: rgba(7, 11, 22, 0.55);
  border-bottom: 1px solid transparent;
  transition: border-color .3s ease, background .3s ease;
}
.site-header.scrolled {
  border-bottom-color: var(--border);
  background: rgba(7, 11, 22, 0.82);
}
.header-inner {
  height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
}
.brand {
  display: flex;
  align-items: center;
  gap: 12px;
}
.brand-mark {
  display: grid; place-items: center;
  width: 38px; height: 38px;
  border-radius: 11px;
  background: var(--grad);
  box-shadow: 0 6px 20px rgba(99, 102, 241, 0.4);
}
.brand-text { display: flex; flex-direction: column; line-height: 1.1; }
.brand-text strong { font-size: 16px; letter-spacing: .5px; }
.brand-text em { font-style: normal; font-size: 11px; color: var(--text-dim); letter-spacing: 1.5px; text-transform: uppercase; }

.site-nav { display: flex; gap: 30px; }
.site-nav a {
  font-size: 14px;
  color: var(--text-muted);
  position: relative;
  padding: 6px 2px;
  transition: color .2s ease;
}
.site-nav a::after {
  content: "";
  position: absolute;
  left: 0; bottom: 0;
  width: 0; height: 2px;
  background: var(--grad);
  border-radius: 2px;
  transition: width .25s ease;
}
.site-nav a:hover, .site-nav a.active { color: var(--text); }
.site-nav a:hover::after, .site-nav a.active::after { width: 100%; }

.nav-toggle {
  display: none;
  flex-direction: column;
  gap: 5px;
  background: none;
  border: none;
  cursor: pointer;
  padding: 8px;
}
.nav-toggle span {
  width: 22px; height: 2px;
  background: var(--text);
  border-radius: 2px;
  transition: transform .25s ease, opacity .25s ease;
}
.nav-toggle.open span:nth-child(1) { transform: translateY(7px) rotate(45deg); }
.nav-toggle.open span:nth-child(2) { opacity: 0; }
.nav-toggle.open span:nth-child(3) { transform: translateY(-7px) rotate(-45deg); }

/* Hero */
.hero {
  position: relative;
  min-height: 100vh;
  display: flex;
  align-items: center;
  padding: 120px 0 90px;
}
.hero-canvas {
  position: absolute;
  inset: 0;
  z-index: -1;
}
.hero-inner { max-width: 820px; }
.eyebrow {
  display: inline-block;
  font-size: 13px;
  letter-spacing: 3px;
  color: var(--cyan);
  text-transform: uppercase;
  padding: 8px 16px;
  border: 1px solid rgba(34, 211, 238, 0.3);
  border-radius: 999px;
  background: rgba(34, 211, 238, 0.06);
  margin-bottom: 28px;
}
.hero h1 {
  font-size: clamp(40px, 6.4vw, 72px);
  line-height: 1.12;
  font-weight: 800;
  letter-spacing: -.5px;
}
.grad-text {
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.hero-en {
  margin-top: 18px;
  font-size: 15px;
  letter-spacing: 2.5px;
  color: var(--text-dim);
  text-transform: uppercase;
}
.hero-sub {
  margin-top: 20px;
  max-width: 600px;
  font-size: 18px;
  color: var(--text-muted);
}
.hero-actions { margin-top: 40px; display: flex; gap: 16px; flex-wrap: wrap; }

.btn {
  display: inline-flex;
  align-items: center;
  justify-content: center;
  gap: 8px;
  padding: 13px 28px;
  border-radius: 999px;
  font-size: 15px;
  font-weight: 600;
  transition: transform .2s ease, box-shadow .2s ease, background .2s ease;
}
.btn:hover { transform: translateY(-2px); }
.btn-primary {
  background: var(--grad);
  color: #fff;
  box-shadow: 0 10px 28px rgba(99, 102, 241, 0.4);
}
.btn-primary:hover { box-shadow: 0 14px 34px rgba(99, 102, 241, 0.55); }
.btn-ghost {
  border: 1px solid var(--border);
  color: var(--text);
  background: var(--surface);
}
.btn-ghost:hover { background: var(--surface-strong); }

.hero-scroll {
  position: absolute;
  left: 50%; bottom: 28px;
  transform: translateX(-50%);
  width: 24px; height: 40px;
  border: 2px solid var(--text-dim);
  border-radius: 999px;
  display: flex;
  justify-content: center;
  padding-top: 7px;
}
.hero-scroll span {
  width: 4px; height: 8px;
  border-radius: 4px;
  background: var(--text-muted);
  animation: scroll 1.6s ease-in-out infinite;
}
@keyframes scroll {
  0%, 100% { transform: translateY(0); opacity: 1; }
  50% { transform: translateY(10px); opacity: .3; }
}

/* Stats */
.stats { padding: 20px 0 80px; }
.stats-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.stat {
  text-align: center;
  padding: 34px 20px;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(8px);
}
.stat strong {
  display: block;
  font-size: 40px;
  font-weight: 800;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  color: transparent;
}
.stat span { font-size: 14px; color: var(--text-muted); }

/* Sections */
.section { padding: 100px 0; }
.section-alt { background: var(--bg-soft); }
.section-head { max-width: 640px; margin-bottom: 56px; }
.section-head h2 {
  font-size: clamp(30px, 4vw, 44px);
  font-weight: 800;
  letter-spacing: -.3px;
  margin: 14px 0 16px;
}
.section-head p { color: var(--text-muted); font-size: 16px; }
.section-tag {
  font-size: 13px;
  letter-spacing: 3px;
  color: var(--cyan);
  text-transform: uppercase;
}

/* About */
.about-grid {
  display: grid;
  grid-template-columns: repeat(3, 1fr);
  gap: 20px;
}
.glass {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  backdrop-filter: blur(10px);
  transition: transform .25s ease, border-color .25s ease, background .25s ease;
}
.glass:hover { transform: translateY(-4px); border-color: rgba(255,255,255,.18); background: var(--surface-strong); }
.about-card { padding: 32px 28px; }
.about-card h3 { font-size: 19px; margin-bottom: 14px; }
.about-card p { color: var(--text-muted); font-size: 15px; }

/* Cards */
.cards-grid {
  display: grid;
  grid-template-columns: repeat(4, 1fr);
  gap: 20px;
}
.card { padding: 30px 26px; }
.card-icon {
  width: 52px; height: 52px;
  display: grid; place-items: center;
  border-radius: 14px;
  background: var(--grad);
  margin-bottom: 22px;
  box-shadow: 0 8px 22px rgba(99, 102, 241, 0.35);
}
.card-icon svg { width: 26px; height: 26px; fill: #fff; }
.card h3 { font-size: 18px; margin-bottom: 12px; }
.card p { color: var(--text-muted); font-size: 14.5px; }

/* Tech list */
.tech-list { display: flex; flex-direction: column; gap: 0; }
.tech-item {
  display: flex;
  gap: 32px;
  padding: 34px 8px;
  border-bottom: 1px solid var(--border);
}
.tech-item:last-child { border-bottom: none; }
.tech-num {
  font-size: 20px;
  font-weight: 800;
  color: transparent;
  background: var(--grad);
  -webkit-background-clip: text;
  background-clip: text;
  min-width: 44px;
}
.tech-body h3 { font-size: 20px; margin-bottom: 8px; }
.tech-body p { color: var(--text-muted); font-size: 15px; max-width: 640px; }

/* Contact */
.contact-wrap {
  display: grid;
  grid-template-columns: 1.1fr 1fr;
  gap: 48px;
  align-items: center;
}
.contact-info h2 { font-size: clamp(28px, 3.6vw, 40px); font-weight: 800; margin: 14px 0 16px; }
.contact-info > p { color: var(--text-muted); margin-bottom: 32px; }
.contact-list li {
  display: flex;
  flex-direction: column;
  gap: 4px;
  padding: 16px 0;
  border-bottom: 1px solid var(--border);
}
.contact-list li:last-child { border-bottom: none; }
.contact-label { font-size: 13px; color: var(--text-dim); letter-spacing: 1px; }
.contact-value { font-size: 16px; color: var(--text); }
.contact-value.link { color: var(--cyan); }
.contact-value.link:hover { text-decoration: underline; }

.contact-panel {
  padding: 44px 40px;
  text-align: center;
}
.contact-panel-mark {
  width: 64px; height: 64px;
  margin: 0 auto 24px;
  display: grid; place-items: center;
  border-radius: 18px;
  background: var(--grad);
  box-shadow: 0 10px 26px rgba(99, 102, 241, 0.4);
}
.contact-panel-mark svg { width: 30px; height: 30px; fill: #fff; }
.contact-panel p { color: var(--text-muted); margin-bottom: 28px; }
.contact-panel p.slogan { font-size: 17px; line-height: 1.9; color: var(--text); }

/* Footer */
.site-footer {
  border-top: 1px solid var(--border);
  padding: 44px 0;
  background: rgba(7, 11, 22, 0.6);
}
.footer-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 24px;
  flex-wrap: wrap;
}
.footer-brand {
  display: flex;
  align-items: center;
  gap: 12px;
  font-size: 15px;
}
.footer-meta {
  display: flex;
  align-items: center;
  gap: 20px;
  flex-wrap: wrap;
  color: var(--text-dim);
  font-size: 13px;
}
.footer-meta a { color: var(--text-muted); transition: color .2s ease; }
.footer-meta a:hover { color: var(--cyan); }
.footer-beian {
  text-align: center;
  padding-top: 22px;
  margin-top: 22px;
  border-top: 1px solid var(--border);
}
.footer-beian a {
  color: var(--text-muted);
  font-size: 14px;
  transition: color .2s ease;
}
.footer-beian a:hover { color: var(--cyan); }

/* Reveal animation */
.reveal {
  opacity: 0;
  transform: translateY(24px);
  transition: opacity .7s cubic-bezier(.2,.7,.2,1), transform .7s cubic-bezier(.2,.7,.2,1);
}
.reveal.in-view { opacity: 1; transform: none; }

/* Responsive */
@media (max-width: 960px) {
  .about-grid, .cards-grid { grid-template-columns: repeat(2, 1fr); }
  .stats-grid { grid-template-columns: repeat(2, 1fr); }
  .contact-wrap { grid-template-columns: 1fr; }
}
@media (max-width: 680px) {
  .site-nav {
    position: fixed;
    top: 72px; left: 0; right: 0;
    flex-direction: column;
    gap: 0;
    background: rgba(7, 11, 22, 0.97);
    border-bottom: 1px solid var(--border);
    padding: 12px 24px 20px;
    transform: translateY(-8px);
    opacity: 0;
    pointer-events: none;
    transition: opacity .25s ease, transform .25s ease;
  }
  .site-nav.open { opacity: 1; transform: none; pointer-events: auto; }
  .site-nav a { padding: 14px 0; border-bottom: 1px solid var(--border); }
  .site-nav a::after { display: none; }
  .nav-toggle { display: flex; }
  .about-grid, .cards-grid { grid-template-columns: 1fr; }
  .stats-grid { grid-template-columns: repeat(2, 1fr); gap: 12px; }
  .hero-actions .btn { width: 100%; }
  .footer-inner { flex-direction: column; align-items: flex-start; }
}