:root {
  --bg: #070b16;
  --bg-2: #0b1222;
  --surface: rgba(255, 255, 255, 0.04);
  --surface-2: rgba(255, 255, 255, 0.06);
  --border: rgba(255, 255, 255, 0.10);
  --border-strong: rgba(255, 255, 255, 0.18);
  --text: #e9eef7;
  --text-dim: #9aa7bd;
  --text-faint: #6b7891;
  --cyan: #5eead4;
  --indigo: #818cf8;
  --blue: #38bdf8;
  --grad: linear-gradient(120deg, #5eead4 0%, #38bdf8 45%, #818cf8 100%);
  --shadow: 0 20px 60px -20px rgba(0, 0, 0, 0.7);
  --radius: 18px;
  --maxw: 1300px;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", Roboto, Helvetica, Arial, sans-serif;
  background: radial-gradient(1200px 800px at 80% -10%, rgba(99, 102, 241, 0.18), transparent 60%),
    radial-gradient(1000px 700px at 0% 10%, rgba(56, 189, 248, 0.14), transparent 55%),
    var(--bg);
  color: var(--text);
  line-height: 1.65;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

/* ---------- 背景层 ---------- */
#bg-canvas { position: fixed; inset: 0; z-index: 0; opacity: 0.55; }
.bg-grid {
  position: fixed; inset: 0; z-index: 0; pointer-events: none;
  background-image: linear-gradient(rgba(255, 255, 255, 0.035) 1px, transparent 1px),
    linear-gradient(90deg, rgba(255, 255, 255, 0.035) 1px, transparent 1px);
  background-size: 54px 54px;
  mask-image: radial-gradient(circle at 50% 30%, #000 0%, transparent 75%);
  -webkit-mask-image: radial-gradient(circle at 50% 30%, #000 0%, transparent 75%);
}
.bg-glow {
  position: fixed; z-index: 0; pointer-events: none; inset: 0;
  background: radial-gradient(600px 400px at var(--mx, 50%) var(--my, 20%), rgba(94, 234, 212, 0.10), transparent 60%);
  transition: background 0.2s ease;
}

main, .nav, .footer { position: relative; z-index: 2; }

/* ---------- 导航 ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(7, 11, 22, 0.55);
  border-bottom: 1px solid transparent;
  transition: border-color 0.3s, background 0.3s;
}
.nav.is-scrolled { border-bottom-color: var(--border); background: rgba(7, 11, 22, 0.82); }
.nav__inner {
  max-width: var(--maxw); margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; gap: 24px;
}
.brand { display: flex; align-items: center; gap: 10px; }
.brand__mark { display: grid; place-items: center; }
.brand__text { font-weight: 800; font-size: 19px; letter-spacing: 0.5px; }
.brand__sub { font-weight: 600; font-size: 13px; color: var(--cyan); margin-left: 4px; letter-spacing: 1px; }
.nav__links { display: flex; gap: 26px; margin-left: auto; font-size: 14.5px; }
.nav__links a { color: var(--text-dim); transition: color 0.2s; }
.nav__links a:hover { color: var(--text); }
.nav__actions { display: flex; gap: 10px; }

/* ---------- 按钮 ---------- */
.btn {
  display: inline-flex; align-items: center; justify-content: center;
  padding: 10px 18px; border-radius: 11px; font-size: 14.5px; font-weight: 600;
  border: 1px solid transparent; cursor: pointer; transition: transform 0.15s, box-shadow 0.25s, background 0.25s;
  white-space: nowrap;
}
.btn--lg { padding: 14px 26px; font-size: 15.5px; border-radius: 13px; }
.btn--primary {
  background: var(--grad); color: #06121b;
  box-shadow: 0 10px 30px -10px rgba(94, 234, 212, 0.55);
}
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 16px 40px -12px rgba(99, 102, 241, 0.6); }
.btn--ghost { background: var(--surface); border-color: var(--border); color: var(--text); }
.btn--ghost:hover { background: var(--surface-2); border-color: var(--border-strong); transform: translateY(-2px); }

/* ---------- Hero ---------- */
.hero {
  max-width: var(--maxw); margin: 0 auto; padding: 92px 24px 70px;
  display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 56px; align-items: center;
}
.badge {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 7px 14px; border-radius: 999px; font-size: 13px; color: var(--text-dim);
  background: var(--surface); border: 1px solid var(--border); margin-bottom: 24px;
}
.badge__dot { width: 7px; height: 7px; border-radius: 50%; background: var(--cyan); box-shadow: 0 0 0 4px rgba(94, 234, 212, 0.18); animation: pulse 2s infinite; }
@keyframes pulse { 0%,100% { opacity: 1; } 50% { opacity: 0.4; } }

.hero__title { font-size: 58px; line-height: 1.05; font-weight: 800; letter-spacing: -0.5px; }
.grad-text { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero__lead { margin-top: 22px; font-size: 17px; color: var(--text-dim); max-width: 540px; }
.hero__actions { margin-top: 34px; display: flex; gap: 14px; flex-wrap: wrap; }
.hero__meta { margin-top: 46px; display: flex; gap: 40px; }
.hero__meta-item { display: flex; flex-direction: column; }
.hero__meta-item strong { font-size: 26px; font-weight: 800; letter-spacing: 0.5px; }
.hero__meta-item span { font-size: 13px; color: var(--text-faint); margin-top: 2px; }

/* Hero 面板 */
.glass-card {
  background: linear-gradient(180deg, rgba(255, 255, 255, 0.07), rgba(255, 255, 255, 0.02));
  border: 1px solid var(--border); border-radius: 20px; padding: 22px;
  box-shadow: var(--shadow); backdrop-filter: blur(10px);
}
.panel__head { display: flex; justify-content: space-between; align-items: center; margin-bottom: 18px; }
.panel__title { font-size: 14px; color: var(--text-dim); font-weight: 600; }
.panel__live { font-size: 11px; font-weight: 700; color: #06121b; background: var(--cyan); padding: 3px 9px; border-radius: 6px; letter-spacing: 1px; }
.topo { width: 100%; height: auto; display: block; margin-top: 4px; }
.topo-link { stroke: url(#linkGrad); stroke-width: 1.6; fill: none; stroke-dasharray: 5 7; animation: topoflow 1.1s linear infinite; }
@keyframes topoflow { to { stroke-dashoffset: -24; } }
.topo-node__bg { fill: url(#nodeGrad); stroke: var(--cyan); stroke-width: 1.5; }
.topo-icon { fill: none; stroke: var(--cyan); stroke-width: 1.6; stroke-linecap: round; stroke-linejoin: round; }
.topo-led { fill: var(--cyan); stroke: none; }
.topo-label { fill: #cfe9ff; font-size: 12px; font-weight: 600; text-anchor: middle; }

/* ---------- 数据条 ---------- */
.stats { max-width: var(--maxw); margin: 0 auto; padding: 8px 24px 40px; }
.stats__inner {
  display: grid; grid-template-columns: repeat(4, 1fr); gap: 1px;
  background: var(--border); border: 1px solid var(--border); border-radius: var(--radius); overflow: hidden;
}
.stat { background: var(--bg-2); padding: 30px 22px; text-align: center; }
.stat__num { display: block; font-size: 38px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat__label { font-size: 13.5px; color: var(--text-dim); margin-top: 6px; display: block; }

/* ---------- 通用 section ---------- */
.section { max-width: var(--maxw); margin: 0 auto; padding: 84px 24px; }
.section--alt { max-width: none; padding-left: 0; padding-right: 0; }
.section--alt > .section__head,
.section--alt > .steps { max-width: var(--maxw); margin-left: auto; margin-right: auto; }
.section--alt { background: linear-gradient(180deg, transparent, rgba(255, 255, 255, 0.025), transparent); }
.section__head { text-align: center; max-width: 640px; margin: 0 auto 52px; }
.kicker { font-size: 12.5px; letter-spacing: 3px; color: var(--cyan); font-weight: 700; }
.section__head h2 { font-size: 38px; font-weight: 800; margin: 12px 0 14px; letter-spacing: -0.4px; }
.section__head p { color: var(--text-dim); font-size: 16px; }
.chips { display: flex; flex-wrap: wrap; gap: 10px; justify-content: center; margin-top: 22px; }
.chips span {
  font-size: 13.5px; color: var(--text-dim);
  padding: 7px 15px; border-radius: 999px;
  background: var(--surface); border: 1px solid var(--border);
  transition: color 0.2s, border-color 0.2s, background 0.2s;
}
.chips span:hover { color: var(--text); border-color: var(--border-strong); background: var(--surface-2); }

/* ---------- FAQ ---------- */
.faq { display: flex; flex-direction: column; gap: 12px; max-width: 820px; margin: 0 auto; }
.faq__item { background: var(--surface); border: 1px solid var(--border); border-radius: 14px; padding: 0 20px; transition: border-color 0.25s, background 0.25s; }
.faq__item[open] { border-color: var(--border-strong); background: var(--surface-2); }
.faq__item summary { cursor: pointer; list-style: none; padding: 17px 0; font-size: 16.5px; font-weight: 600; display: flex; align-items: center; justify-content: space-between; gap: 16px; }
.faq__item summary::-webkit-details-marker { display: none; }
.faq__item summary::after { content: "+"; font-size: 24px; line-height: 1; color: var(--cyan); font-weight: 400; transition: transform 0.25s; }
.faq__item[open] summary::after { transform: rotate(45deg); }
.faq__item p { color: var(--text-dim); font-size: 15px; padding: 0 0 18px; margin: 0; }

/* ---------- 数据中心 ---------- */
.dc-grid { display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.dc { background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius); padding: 26px 24px; transition: transform 0.25s, border-color 0.25s, background 0.25s; }
.dc:hover { transform: translateY(-6px); border-color: var(--border-strong); background: var(--surface-2); }
.dc__region { font-size: 12.5px; letter-spacing: 1px; color: var(--cyan); font-weight: 700; }
.dc__city { font-size: 22px; font-weight: 800; margin: 8px 0 10px; }
.dc__desc { color: var(--text-dim); font-size: 14px; }
@media (max-width: 960px) { .dc-grid { grid-template-columns: repeat(2, 1fr); } }
@media (max-width: 560px) { .dc-grid { grid-template-columns: 1fr; } }

/* 数据中心 · 地图表达 */
.dc-layout { display: grid; grid-template-columns: 1.25fr 1fr; gap: 40px; align-items: center; }
.dc-map { width: 100%; }
.china-map { width: 100%; height: 460px; }
@media (max-width: 960px) { .china-map { height: 360px; } }
.dc-legend { display: flex; flex-direction: column; gap: 16px; }
.dc-leg { display: flex; gap: 12px; align-items: flex-start; }
.dc-leg__dot { width: 10px; height: 10px; border-radius: 50%; background: var(--cyan); margin-top: 6px; flex: none; box-shadow: 0 0 0 4px rgba(94, 234, 212, 0.15); }
.dc-leg strong { font-size: 16px; }
.dc-leg p { color: var(--text-dim); font-size: 14px; margin-top: 3px; }
@media (max-width: 960px) { .dc-layout { grid-template-columns: 1fr; gap: 28px; } }

/* 卡片 */
.cards { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.card {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 28px; transition: transform 0.25s, border-color 0.25s, background 0.25s;
}
.card:hover { transform: translateY(-6px); border-color: var(--border-strong); background: var(--surface-2); }
.card__icon {
  width: 52px; height: 52px; border-radius: 14px; display: grid; place-items: center;
  color: var(--cyan); background: rgba(94, 234, 212, 0.10); border: 1px solid rgba(94, 234, 212, 0.22);
  margin-bottom: 18px;
}
.card h3 { font-size: 19px; font-weight: 700; margin-bottom: 8px; }
.card p { color: var(--text-dim); font-size: 14.5px; }

/* 步骤 */
.steps { list-style: none; display: grid; grid-template-columns: repeat(4, 1fr); gap: 20px; }
.step {
  background: var(--surface); border: 1px solid var(--border); border-radius: var(--radius);
  padding: 26px 22px; position: relative; overflow: hidden;
}
.step::before { content: ""; position: absolute; top: 0; left: 0; right: 0; height: 3px; background: var(--grad); opacity: 0.85; }
.step__no { font-size: 30px; font-weight: 800; color: transparent; background: var(--grad); -webkit-background-clip: text; background-clip: text; }
.step h3 { font-size: 17px; margin: 10px 0 8px; font-weight: 700; }
.step p { color: var(--text-dim); font-size: 14px; }

/* 架构 */
.arch { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.arch__col { border: 1px solid var(--border); border-radius: var(--radius); padding: 28px; background: var(--surface); }
.arch__col h3 { font-size: 18px; margin-bottom: 10px; font-weight: 700; }
.arch__col h3::before { content: ""; display: inline-block; width: 8px; height: 8px; border-radius: 50%; background: var(--cyan); margin-right: 10px; box-shadow: 0 0 0 4px rgba(94, 234, 212, 0.16); }
.arch__col p { color: var(--text-dim); font-size: 14.5px; }


/* ---------- 页脚 ---------- */
.footer { border-top: 1px solid var(--border); background: rgba(7, 11, 22, 0.6); }
.footer__inner { max-width: var(--maxw); margin: 0 auto; padding: 56px 24px 30px; display: flex; gap: 50px; flex-wrap: wrap; justify-content: space-between; }
.footer__brand { max-width: 300px; }
.footer__brand p { color: var(--text-dim); font-size: 14px; margin-top: 10px; }
.footer__cols { display: flex; gap: 60px; flex-wrap: wrap; }
.footer__cols h4 { font-size: 14px; margin-bottom: 14px; color: var(--text); }
.footer__cols a { display: block; color: var(--text-dim); font-size: 14px; margin-bottom: 9px; transition: color 0.2s; }
.footer__cols a:hover { color: var(--cyan); }
.footer__bar { max-width: var(--maxw); margin: 0 auto; padding: 18px 24px 30px; border-top: 1px solid var(--border); display: flex; justify-content: space-between; flex-wrap: wrap; gap: 8px; color: var(--text-faint); font-size: 13px; }

/* ---------- 滚动揭示 ---------- */
.reveal { opacity: 0; transform: translateY(28px); transition: opacity 0.7s ease, transform 0.7s ease; }
.reveal.is-visible { opacity: 1; transform: none; }

/* ---------- 响应式 ---------- */
@media (max-width: 960px) {
  .hero { grid-template-columns: 1fr; padding-top: 60px; gap: 36px; }
  .hero__title { font-size: 44px; }
  .cards, .arch, .steps { grid-template-columns: repeat(2, 1fr); }
  .stats__inner { grid-template-columns: repeat(2, 1fr); }
  .nav__links { display: none; }
}
@media (max-width: 560px) {
  .hero__title { font-size: 36px; }
  .cards, .arch, .steps, .stats__inner { grid-template-columns: 1fr; }
  .hero__meta { gap: 24px; }
  .section__head h2 { font-size: 28px; }
  .footer__inner { flex-direction: column; gap: 30px; }
}
@media (prefers-reduced-motion: reduce) {
  .reveal { transition: none; opacity: 1; transform: none; }
  .badge__dot { animation: none; }
}