/* ===== 设计变量：科技感深色主题 ===== */
:root {
  --bg: #060912;
  --bg-2: #0a0f1f;
  --surface: rgba(18, 26, 48, 0.55);
  --surface-border: rgba(120, 160, 255, 0.16);
  --text: #e6edff;
  --text-dim: #9aa7c7;
  --cyan: #22d3ee;
  --blue: #60a5fa;
  --purple: #a855f7;
  --grad: linear-gradient(100deg, #22d3ee 0%, #60a5fa 45%, #a855f7 100%);
  --radius: 16px;
  --maxw: 1120px;
  --shadow-glow: 0 0 0 1px rgba(120,160,255,.12), 0 18px 50px -20px rgba(34,211,238,.35);
}

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

html { scroll-behavior: smooth; }

body {
  font-family: "PingFang SC", "Microsoft YaHei", "Hiragino Sans GB", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  color: var(--text);
  background: var(--bg);
  line-height: 1.7;
  overflow-x: hidden;
  -webkit-font-smoothing: antialiased;
}

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

/* ===== 背景装饰 ===== */
.bg-grid {
  position: fixed; inset: 0; z-index: -2;
  background-image:
    linear-gradient(rgba(120,160,255,.05) 1px, transparent 1px),
    linear-gradient(90deg, rgba(120,160,255,.05) 1px, transparent 1px);
  background-size: 46px 46px;
  mask-image: radial-gradient(ellipse 80% 60% at 50% 0%, #000 40%, transparent 100%);
}
.bg-glow {
  position: fixed; z-index: -1; border-radius: 50%;
  filter: blur(90px); opacity: .5; pointer-events: none;
}
.bg-glow--1 { width: 520px; height: 520px; top: -160px; left: -120px;
  background: radial-gradient(circle, rgba(34,211,238,.55), transparent 70%); }
.bg-glow--2 { width: 560px; height: 560px; top: 220px; right: -180px;
  background: radial-gradient(circle, rgba(168,85,247,.5), transparent 70%); }

/* ===== 导航 ===== */
.nav {
  position: sticky; top: 0; z-index: 50;
  backdrop-filter: blur(14px);
  background: rgba(6, 9, 18, 0.6);
  border-bottom: 1px solid var(--surface-border);
}
.nav__inner {
  max-width: var(--maxw); margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between;
  padding: 14px 22px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; }
.brand__mark { display: grid; place-items: center; }
.brand__text { font-size: 19px; letter-spacing: .5px;
  background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.nav__links { display: flex; gap: 6px; }
.nav__link {
  padding: 8px 14px; border-radius: 10px; color: var(--text-dim);
  font-size: 15px; transition: .2s;
}
.nav__link:hover, .nav__link.active { color: var(--text); background: rgba(120,160,255,.1); }
.nav__toggle { display: none; flex-direction: column; gap: 5px; background: none; border: 0; cursor: pointer; padding: 8px; }
.nav__toggle span { width: 24px; height: 2px; background: var(--text); border-radius: 2px; transition: .3s; }

/* ===== Hero ===== */
.hero { max-width: var(--maxw); margin: 0 auto; padding: 92px 22px 64px; text-align: center; }
.hero__eyebrow { color: var(--cyan); letter-spacing: 3px; font-size: 13px; font-weight: 600; margin-bottom: 18px; }
.hero__title { font-size: clamp(42px, 8vw, 76px); font-weight: 800; line-height: 1.05; letter-spacing: 1px; }
.grad { background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.hero__subtitle { max-width: 640px; margin: 22px auto 0; color: var(--text-dim); font-size: clamp(15px, 2.4vw, 18px); }
.hero__actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; margin-top: 34px; }
.hero__stats { display: flex; gap: 40px; justify-content: center; margin-top: 54px; flex-wrap: wrap; }
.stat { display: flex; flex-direction: column; align-items: center; }
.stat__num { font-size: 30px; font-weight: 800; background: var(--grad); -webkit-background-clip: text; background-clip: text; color: transparent; }
.stat__label { font-size: 13px; color: var(--text-dim); margin-top: 4px; }

/* ===== 按钮 ===== */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 12px 24px; border-radius: 12px; font-weight: 600; font-size: 15px;
  transition: transform .15s, box-shadow .25s, background .25s; cursor: pointer; border: 1px solid transparent;
}
.btn--primary { background: var(--grad); color: #04122b; box-shadow: 0 12px 30px -12px rgba(34,211,238,.6); }
.btn--primary:hover { transform: translateY(-2px); box-shadow: 0 18px 40px -12px rgba(168,85,247,.7); }
.btn--ghost { background: rgba(120,160,255,.08); color: var(--text); border-color: var(--surface-border); }
.btn--ghost:hover { background: rgba(120,160,255,.16); transform: translateY(-2px); }
.btn--lg { padding: 15px 30px; font-size: 16px; }

/* ===== 区块 ===== */
.section { max-width: var(--maxw); margin: 0 auto; padding: 72px 22px; }
.section--alt { max-width: none; background: linear-gradient(180deg, rgba(10,15,31,0), rgba(14,20,40,.6), rgba(10,15,31,0)); }
.section--alt > * { max-width: var(--maxw); margin-left: auto; margin-right: auto; }
.section__head { text-align: center; margin-bottom: 44px; }
.section__tag { color: var(--cyan); letter-spacing: 4px; font-size: 12px; font-weight: 700; }
.section__title { font-size: clamp(28px, 5vw, 40px); font-weight: 800; margin: 10px 0 12px; }
.section__desc { color: var(--text-dim); max-width: 560px; margin: 0 auto; }

/* ===== 卡片 ===== */
.cards { display: grid; gap: 20px; }
.cards--3 { grid-template-columns: repeat(3, 1fr); }
.cards--2 { grid-template-columns: repeat(2, 1fr); }
.card {
  position: relative; padding: 26px; border-radius: var(--radius);
  background: var(--surface); border: 1px solid var(--surface-border);
  backdrop-filter: blur(8px); transition: transform .25s, box-shadow .3s, border-color .3s;
  overflow: hidden;
}
.card::before {
  content: ""; position: absolute; inset: 0; border-radius: var(--radius);
  padding: 1px; background: var(--grad);
  -webkit-mask: linear-gradient(#000 0 0) content-box, linear-gradient(#000 0 0);
  -webkit-mask-composite: xor; mask-composite: exclude;
  opacity: 0; transition: opacity .3s;
}
.card:hover { transform: translateY(-6px); box-shadow: var(--shadow-glow); }
.card:hover::before { opacity: .9; }
.card__badge { display: inline-block; font-size: 12px; font-weight: 700; padding: 4px 12px; border-radius: 999px; margin-bottom: 14px; }
.card__badge--cyan { background: rgba(34,211,238,.14); color: var(--cyan); }
.card__badge--purple { background: rgba(168,85,247,.16); color: #c99bff; }
.card__badge--blue { background: rgba(96,165,250,.16); color: var(--blue); }
.card__title { font-size: 19px; font-weight: 700; margin-bottom: 10px; }
.card__text { color: var(--text-dim); font-size: 15px; }
.card__icon { font-size: 26px; margin-bottom: 12px; }
.card__list { margin: 8px 0 0 18px; color: var(--text-dim); font-size: 14.5px; }
.card__list li { margin-bottom: 8px; }
.card__list b { color: var(--text); }

/* ===== CTA ===== */
.cta { text-align: center; padding: 56px 22px; border-radius: 22px;
  background: var(--surface); border: 1px solid var(--surface-border); }
.cta__title { font-size: clamp(26px, 5vw, 38px); font-weight: 800; }
.cta__text { color: var(--text-dim); margin: 14px 0 28px; }

/* ===== 页脚 ===== */
.footer { border-top: 1px solid var(--surface-border); margin-top: 30px; background: rgba(6,9,18,.7); }
.footer__inner { max-width: var(--maxw); margin: 0 auto; padding: 36px 22px;
  display: flex; justify-content: space-between; gap: 24px; flex-wrap: wrap; }
.footer__slogan { color: var(--text-dim); font-size: 14px; margin-top: 8px; max-width: 280px; }
.footer__meta { text-align: right; }
.footer__line { font-size: 14.5px; margin-bottom: 8px; color: var(--text-dim); }
.footer__meta a { color: var(--cyan); }
.footer__meta a:hover { text-decoration: underline; }
.footer__copy { font-size: 13px; color: #6b7799; margin-top: 6px; }

/* ===== 滚动揭示动画 ===== */
.reveal { opacity: 0; transform: translateY(26px); transition: opacity .6s ease, transform .6s ease; }
.reveal.in { opacity: 1; transform: none; }

/* ===== 响应式 ===== */
@media (max-width: 880px) {
  .cards--3, .cards--2 { grid-template-columns: 1fr; }
  .nav__links {
    position: absolute; top: 100%; left: 0; right: 0;
    flex-direction: column; gap: 0; padding: 8px 16px 16px;
    background: rgba(6,9,18,.96); border-bottom: 1px solid var(--surface-border);
    display: none;
  }
  .nav__links.open { display: flex; }
  .nav__link { padding: 12px 8px; }
  .nav__toggle { display: flex; }
  .footer__inner { flex-direction: column; }
  .footer__meta { text-align: left; }
}