:root {
  --brand-1: #6366f1;
  --brand-2: #06b6d4;
  --brand-3: #0ea5e9;
  --cta-1: #f97316;
  --cta-2: #ef4444;
  --ink: #0f172a;
  --ink-soft: #334155;
  --muted: #64748b;
  --line: #e2e8f0;
  --bg: #f8fafc;
  --bg-soft: #eef2ff;
  --card: #ffffff;
  --dark: #0b1220;
  --dark-2: #101a2e;
  --radius: 18px;
  --shadow: 0 10px 40px rgba(15, 23, 42, 0.08);
  --shadow-lg: 0 24px 60px rgba(15, 23, 42, 0.16);
}

* { 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", "Segoe UI", Roboto, Arial, sans-serif;
  color: var(--ink);
  background: var(--bg);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

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

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

.container { width: 100%; max-width: 1180px; margin: 0 auto; padding: 0 24px; }

.section { padding: 88px 0; }
.section-head { text-align: center; max-width: 720px; margin: 0 auto 56px; }
.section-head .eyebrow {
  display: inline-block; font-size: 13px; font-weight: 700; letter-spacing: 2px;
  text-transform: uppercase; color: var(--brand-1); background: var(--bg-soft);
  padding: 6px 14px; border-radius: 999px; margin-bottom: 16px;
}
.section-head h2 { font-size: 36px; line-height: 1.25; font-weight: 800; letter-spacing: -0.5px; }
.section-head p { color: var(--muted); font-size: 17px; margin-top: 14px; }

.grad-text {
  background: linear-gradient(120deg, var(--brand-1), var(--brand-2));
  -webkit-background-clip: text; background-clip: text; color: transparent;
}

.btn {
  display: inline-flex; align-items: center; justify-content: center; gap: 8px;
  font-weight: 700; border-radius: 999px; padding: 14px 30px; font-size: 16px;
  cursor: pointer; border: none; transition: transform .18s ease, box-shadow .18s ease, background .18s ease;
  white-space: nowrap;
}
.btn:hover { transform: translateY(-2px); }
.btn:active { transform: translateY(0); }
.btn-primary {
  color: #fff; background: linear-gradient(120deg, var(--brand-1), var(--brand-2));
  box-shadow: 0 12px 30px rgba(99, 102, 241, 0.32);
}
.btn-primary:hover { box-shadow: 0 16px 40px rgba(99, 102, 241, 0.42); }
.btn-download {
  color: #fff; background: linear-gradient(120deg, var(--cta-1), var(--cta-2));
  box-shadow: 0 12px 30px rgba(239, 68, 68, 0.32);
}
.btn-download:hover { box-shadow: 0 16px 42px rgba(239, 68, 68, 0.45); }
.btn-ghost {
  color: var(--ink); background: #fff; border: 1.5px solid var(--line);
}
.btn-ghost:hover { border-color: var(--brand-1); color: var(--brand-1); }
.btn-sm { padding: 10px 20px; font-size: 14px; }
.btn-lg { padding: 17px 38px; font-size: 18px; }
.btn-block { width: 100%; }

.site-header {
  position: sticky; top: 0; z-index: 60;
  background: rgba(255, 255, 255, 0.86); backdrop-filter: blur(14px);
  border-bottom: 1px solid rgba(226, 232, 240, 0.7);
}
.nav-wrap { display: flex; align-items: center; justify-content: space-between; height: 72px; gap: 24px; }
.brand { display: inline-flex; align-items: center; gap: 10px; font-weight: 800; font-size: 19px; }
.brand img { width: 34px; height: 34px; border-radius: 9px; }
.brand-accent { color: var(--brand-1); }
.main-nav { display: flex; align-items: center; gap: 28px; }
.main-nav a { font-size: 15px; font-weight: 600; color: var(--ink-soft); transition: color .15s ease; }
.main-nav a:hover, .main-nav a.active { color: var(--brand-1); }
.nav-actions { display: flex; align-items: center; gap: 14px; }
.nav-toggle { display: none; background: none; border: none; font-size: 26px; cursor: pointer; color: var(--ink); }

.hero {
  position: relative; overflow: hidden; color: #fff;
  background: radial-gradient(1200px 600px at 80% -10%, rgba(6, 182, 212, 0.35), transparent 60%),
              radial-gradient(900px 500px at 10% 20%, rgba(99, 102, 241, 0.45), transparent 55%),
              linear-gradient(140deg, #0b1220 0%, #141a3a 55%, #0f2240 100%);
}
.hero-inner { display: grid; grid-template-columns: 1.05fr 0.95fr; gap: 56px; align-items: center; padding: 96px 0 110px; }
.hero-left .hero-badge {
  display: inline-flex; align-items: center; gap: 8px; font-size: 13px; font-weight: 700;
  color: #a5f3fc; background: rgba(6, 182, 212, 0.14); border: 1px solid rgba(6, 182, 212, 0.35);
  padding: 7px 14px; border-radius: 999px; margin-bottom: 22px;
}
.hero-left h1 { font-size: 52px; line-height: 1.14; font-weight: 900; letter-spacing: -1px; margin-bottom: 20px; }
.hero-left h1 .grad-text { background: linear-gradient(120deg, #818cf8, #22d3ee); -webkit-background-clip: text; background-clip: text; }
.hero-left .lead { font-size: 18px; color: #cbd5e1; max-width: 540px; margin-bottom: 30px; }
.hero-cta { display: flex; flex-wrap: wrap; gap: 14px; margin-bottom: 34px; }
.hero-stats { display: flex; gap: 36px; flex-wrap: wrap; }
.hero-stats .stat b { display: block; font-size: 28px; font-weight: 800; }
.hero-stats .stat span { font-size: 13px; color: #94a3b8; }

.hero-right { display: flex; justify-content: center; }
.app-window {
  width: 100%; max-width: 400px; background: #0d1526; border: 1px solid rgba(255, 255, 255, 0.1);
  border-radius: 22px; box-shadow: var(--shadow-lg); overflow: hidden;
}
.app-titlebar { display: flex; align-items: center; gap: 8px; padding: 14px 18px; background: #101a2e; border-bottom: 1px solid rgba(255,255,255,0.06); }
.app-titlebar .dot { width: 11px; height: 11px; border-radius: 50%; }
.app-titlebar .dot.red { background: #f87171; }
.app-titlebar .dot.yellow { background: #fbbf24; }
.app-titlebar .dot.green { background: #34d399; }
.app-titlebar .app-title { margin-left: 6px; font-size: 13px; color: #94a3b8; font-weight: 600; }
.app-body { padding: 26px 24px 30px; text-align: center; }
.status-row { display: flex; align-items: center; justify-content: space-between; margin-bottom: 20px; }
.status-badge {
  font-size: 13px; font-weight: 700; color: #fca5a5; background: rgba(248, 113, 113, 0.14);
  padding: 6px 14px; border-radius: 999px;
}
.status-badge.on { color: #86efac; background: rgba(52, 211, 153, 0.14); }
.conn-time { font-size: 13px; color: #64748b; font-variant-numeric: tabular-nums; }
.connect-btn {
  width: 148px; height: 148px; border-radius: 50%; border: none; cursor: pointer;
  background: linear-gradient(140deg, #f97316, #ef4444); color: #fff; margin: 8px auto 26px;
  display: flex; align-items: center; justify-content: center; position: relative;
  box-shadow: 0 0 0 10px rgba(239, 68, 68, 0.12), 0 18px 40px rgba(239, 68, 68, 0.35);
  transition: transform .2s ease, box-shadow .2s ease;
}
.connect-btn:hover { transform: scale(1.03); }
.connect-btn.connected {
  background: linear-gradient(140deg, #10b981, #22c55e);
  box-shadow: 0 0 0 10px rgba(16, 185, 129, 0.14), 0 18px 40px rgba(16, 185, 129, 0.35);
}
.connect-btn .btn-label { font-size: 20px; font-weight: 800; letter-spacing: 1px; }
.app-meta { display: grid; grid-template-columns: repeat(3, 1fr); gap: 10px; margin-bottom: 20px; }
.meta-item { background: #101a2e; border: 1px solid rgba(255,255,255,0.06); border-radius: 14px; padding: 12px 8px; }
.meta-item label { display: block; font-size: 11px; color: #64748b; margin-bottom: 4px; }
.meta-item span { font-size: 14px; font-weight: 700; color: #e2e8f0; }
.speed-panel { display: grid; grid-template-columns: 1fr 1fr; gap: 10px; }
.speed-item { background: #101a2e; border: 1px solid rgba(255,255,255,0.06); border-radius: 14px; padding: 12px; text-align: left; }
.speed-item label { display: block; font-size: 11px; color: #64748b; margin-bottom: 3px; }
.speed-item span { font-size: 18px; font-weight: 800; color: #22d3ee; font-variant-numeric: tabular-nums; }

.grid { display: grid; gap: 24px; }
.grid-3 { grid-template-columns: repeat(3, 1fr); }
.grid-4 { grid-template-columns: repeat(4, 1fr); }
.grid-2 { grid-template-columns: repeat(2, 1fr); }

.card {
  background: var(--card); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 28px; box-shadow: var(--shadow); transition: transform .18s ease, box-shadow .18s ease;
}
.card:hover { transform: translateY(-4px); box-shadow: var(--shadow-lg); }
.feature-icon {
  width: 52px; height: 52px; border-radius: 14px; display: flex; align-items: center; justify-content: center;
  font-size: 24px; font-weight: 800; color: #fff; margin-bottom: 18px;
  background: linear-gradient(135deg, var(--brand-1), var(--brand-2));
}
.card h3 { font-size: 19px; font-weight: 800; margin-bottom: 10px; }
.card p { color: var(--muted); font-size: 15px; }

.step-num {
  display: inline-flex; align-items: center; justify-content: center; width: 42px; height: 42px;
  border-radius: 50%; background: linear-gradient(135deg, var(--brand-1), var(--brand-2));
  color: #fff; font-weight: 800; font-size: 18px; margin-bottom: 16px;
}

.cta-band {
  background: radial-gradient(900px 400px at 50% -20%, rgba(249, 115, 22, 0.35), transparent 60%),
              linear-gradient(140deg, #0b1220, #2a1a3a);
  color: #fff; text-align: center; border-radius: 28px; padding: 64px 32px;
}
.cta-band h2 { font-size: 36px; font-weight: 900; margin-bottom: 14px; }
.cta-band p { color: #cbd5e1; max-width: 560px; margin: 0 auto 28px; }

.site-footer { background: var(--dark); color: #cbd5e1; padding: 64px 0 0; margin-top: 40px; }
.footer-grid { display: grid; grid-template-columns: 1.5fr 1fr 1fr 1fr; gap: 32px; padding-bottom: 40px; }
.footer-brand p { color: #94a3b8; margin-top: 16px; font-size: 14px; max-width: 300px; }
.footer-col h4 { color: #fff; font-size: 15px; font-weight: 700; margin-bottom: 16px; }
.footer-col a { display: block; color: #94a3b8; font-size: 14px; margin-bottom: 10px; transition: color .15s ease; }
.footer-col a:hover { color: #22d3ee; }
.friend-links { border-top: 1px solid rgba(255,255,255,0.08); padding: 24px 0; font-size: 14px; color: #94a3b8; }
.friend-links a { color: #94a3b8; }
.friend-links a:hover { color: #22d3ee; }
.footer-bottom { border-top: 1px solid rgba(255,255,255,0.08); padding: 22px 0 30px; text-align: center; font-size: 13px; color: #64748b; }
.footer-bottom a { color: #94a3b8; }
.footer-bottom a:hover { color: #22d3ee; }

.page-hero { background: linear-gradient(140deg, #0b1220, #141a3a 55%, #0f2240); color: #fff; padding: 72px 0; text-align: center; }
.page-hero h1 { font-size: 40px; font-weight: 900; margin-bottom: 14px; }
.page-hero p { color: #cbd5e1; max-width: 640px; margin: 0 auto; font-size: 17px; }

.faq-cat { margin-bottom: 40px; }
.faq-cat-head {
  display: flex; align-items: center; gap: 12px; margin-bottom: 18px;
  font-size: 20px; font-weight: 800;
}
.faq-cat-head .cat-badge {
  width: 40px; height: 40px; border-radius: 12px; display: inline-flex; align-items: center; justify-content: center;
  color: #fff; font-weight: 800; background: linear-gradient(135deg, var(--brand-1), var(--brand-2));
}
details.faq-item { background: var(--card); border: 1px solid var(--line); border-radius: 14px; margin-bottom: 12px; overflow: hidden; }
details.faq-item summary {
  cursor: pointer; list-style: none; padding: 20px 24px; font-weight: 700; font-size: 16px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
details.faq-item summary::-webkit-details-marker { display: none; }
details.faq-item summary::after { content: "+"; font-size: 24px; color: var(--brand-1); font-weight: 700; }
details.faq-item[open] summary::after { content: "−"; }
.faq-answer { padding: 0 24px 22px; color: var(--ink-soft); font-size: 15px; }
.faq-answer ol { margin-left: 20px; }
.faq-answer ol li { margin-bottom: 8px; }

.download-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.dl-card { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 30px; text-align: center; box-shadow: var(--shadow); }
.dl-card .os-icon {
  width: 64px; height: 64px; border-radius: 18px; margin: 0 auto 18px; display: flex; align-items: center; justify-content: center;
  font-weight: 900; font-size: 15px; color: #fff; background: linear-gradient(135deg, var(--brand-1), var(--brand-2));
}
.dl-card h3 { font-size: 20px; font-weight: 800; margin-bottom: 6px; }
.dl-card .ver { color: var(--muted); font-size: 13px; margin-bottom: 18px; }

.info-list { list-style: none; }
.info-list li { position: relative; padding-left: 28px; margin-bottom: 14px; color: var(--ink-soft); }
.info-list li::before { content: "✓"; position: absolute; left: 0; top: 0; color: #10b981; font-weight: 800; }

.pill-row { display: flex; flex-wrap: wrap; gap: 10px; }
.pill { background: var(--bg-soft); color: var(--brand-1); font-weight: 600; font-size: 14px; padding: 8px 16px; border-radius: 999px; }

.breadcrumb { font-size: 13px; color: var(--muted); margin-bottom: 24px; }
.breadcrumb a { color: var(--brand-1); }

.sitemap-grid { display: grid; grid-template-columns: repeat(3, 1fr); gap: 24px; }
.sitemap-group { background: var(--card); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; box-shadow: var(--shadow); }
.sitemap-group h3 { font-size: 17px; font-weight: 800; margin-bottom: 14px; }
.sitemap-group a { display: block; color: var(--ink-soft); font-size: 14px; margin-bottom: 8px; }
.sitemap-group a:hover { color: var(--brand-1); }

@media (max-width: 960px) {
  .hero-inner { grid-template-columns: 1fr; padding: 60px 0 80px; }
  .hero-left h1 { font-size: 38px; }
  .grid-3, .grid-4 { grid-template-columns: 1fr 1fr; }
  .footer-grid { grid-template-columns: 1fr 1fr; }
  .download-grid { grid-template-columns: 1fr 1fr; }
  .sitemap-grid { grid-template-columns: 1fr 1fr; }
  .main-nav, .nav-actions .btn-download { display: none; }
  .nav-toggle { display: block; }
  .main-nav.open { display: flex; flex-direction: column; position: absolute; top: 72px; left: 0; right: 0; background: #fff; padding: 20px; border-bottom: 1px solid var(--line); gap: 16px; }
}

@media (max-width: 600px) {
  .grid-3, .grid-4, .grid-2, .footer-grid, .download-grid, .sitemap-grid { grid-template-columns: 1fr; }
  .hero-left h1 { font-size: 32px; }
  .section { padding: 60px 0; }
  .section-head h2 { font-size: 28px; }
}