:root {
  --bg: #0b0e14;
  --bg-soft: #11151f;
  --bg-card: #151a26;
  --border: #232a3a;
  --text: #e6e9f0;
  --text-dim: #9aa3b5;
  --accent: #4d6bfe;
  --accent-soft: rgba(77, 107, 254, 0.14);
  --green: #34d399;
  --radius: 14px;
  --maxw: 1080px;
  --font: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  --mono: ui-monospace, SFMono-Regular, "SF Mono", Menlo, Consolas, monospace;
}

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

html { scroll-behavior: smooth; }

body {
  font-family: var(--font);
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

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

/* ---------- Nav ---------- */
.nav {
  position: sticky; top: 0; z-index: 50;
  background: rgba(11, 14, 20, 0.85);
  backdrop-filter: blur(12px);
  border-bottom: 1px solid var(--border);
}
.nav-inner {
  max-width: var(--maxw); margin: 0 auto; padding: 14px 24px;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
}
.brand { display: flex; align-items: center; gap: 10px; font-weight: 700; font-size: 17px; color: var(--text); }
.brand:hover { text-decoration: none; }
.brand-logo {
  width: 30px; height: 30px; border-radius: 8px; display: grid; place-items: center;
  background: linear-gradient(135deg, #4d6bfe, #22d3ee);
  font-size: 16px;
}
.nav-links { display: flex; align-items: center; gap: 22px; font-size: 15px; }
.nav-links a { color: var(--text-dim); }
.nav-links a:hover { color: var(--text); text-decoration: none; }
.nav-links a.active { color: var(--text); font-weight: 600; }
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  background: var(--accent); color: #fff !important;
  padding: 10px 20px; border-radius: 10px; font-weight: 600; font-size: 15px;
  transition: transform .12s ease, box-shadow .12s ease;
}
.btn:hover { text-decoration: none; transform: translateY(-1px); box-shadow: 0 6px 20px rgba(77, 107, 254, 0.35); }
.btn-ghost {
  background: transparent; color: var(--text) !important;
  border: 1px solid var(--border);
}
.btn-ghost:hover { box-shadow: none; border-color: var(--accent); }

/* ---------- Hero ---------- */
.hero { padding: 88px 0 56px; text-align: center; }
.hero-badge {
  display: inline-flex; align-items: center; gap: 8px;
  font-size: 13px; color: var(--text-dim);
  border: 1px solid var(--border); background: var(--bg-soft);
  padding: 6px 14px; border-radius: 999px; margin-bottom: 22px;
}
.hero-badge .dot { width: 8px; height: 8px; border-radius: 50%; background: var(--green); }
.hero h1 {
  font-size: clamp(34px, 6vw, 56px);
  line-height: 1.15; font-weight: 800;
  background: linear-gradient(120deg, #fff 30%, #8ea2ff);
  -webkit-background-clip: text; background-clip: text; -webkit-text-fill-color: transparent;
  margin-bottom: 18px;
}
.hero p.sub {
  max-width: 640px; margin: 0 auto 34px;
  font-size: 18px; color: var(--text-dim);
}
.hero-actions { display: flex; gap: 14px; justify-content: center; flex-wrap: wrap; }
.hero-note { margin-top: 16px; font-size: 13px; color: var(--text-dim); }

/* ---------- Sections ---------- */
.section { padding: 56px 0; }
.section-alt { background: var(--bg-soft); border-top: 1px solid var(--border); border-bottom: 1px solid var(--border); }
.section-title { font-size: 28px; font-weight: 800; margin-bottom: 8px; }
.section-sub { color: var(--text-dim); margin-bottom: 32px; }

/* ---------- Feature grid ---------- */
.grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; }
.card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 22px;
  transition: border-color .15s ease, transform .15s ease;
}
.card:hover { border-color: var(--accent); transform: translateY(-2px); }
.card .icon { font-size: 26px; margin-bottom: 12px; }
.card h3 { font-size: 16px; margin-bottom: 8px; }
.card p { font-size: 14px; color: var(--text-dim); }

/* ---------- Download ---------- */
.dl-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(240px, 1fr)); gap: 18px; }
.dl-card {
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 24px; text-align: center;
}
.dl-card .os { font-size: 34px; margin-bottom: 8px; }
.dl-card h3 { font-size: 17px; margin-bottom: 4px; }
.dl-card .fmt { font-size: 13px; color: var(--text-dim); margin-bottom: 16px; font-family: var(--mono); }
.dl-card .btn { width: 100%; justify-content: center; }
.dl-actions { display: flex; flex-direction: column; gap: 10px; }
.dl-note { margin-top: 14px; font-size: 12px; line-height: 1.5; color: var(--text-dim); }
.dl-tip { margin-top: 20px; font-size: 13px; color: var(--text-dim); text-align: center; }

/* ---------- Steps ---------- */
.steps { counter-reset: step; display: grid; gap: 14px; max-width: 720px; }
.step {
  display: flex; gap: 16px; align-items: flex-start;
  background: var(--bg-card); border: 1px solid var(--border);
  border-radius: var(--radius); padding: 18px 20px;
}
.step::before {
  counter-increment: step; content: counter(step);
  flex: none; width: 28px; height: 28px; border-radius: 50%;
  background: var(--accent-soft); color: var(--accent);
  display: grid; place-items: center; font-weight: 700; font-size: 14px;
}
.step p { font-size: 15px; }

/* ---------- Code ---------- */
pre {
  background: #0a0d13; border: 1px solid var(--border); border-radius: 10px;
  padding: 16px 18px; overflow-x: auto; font-size: 14px;
  font-family: var(--mono); line-height: 1.6; margin: 16px 0;
}
code { font-family: var(--mono); font-size: .9em; background: var(--accent-soft); color: var(--accent); padding: 2px 6px; border-radius: 6px; }
pre code { background: none; color: #c9d4e8; padding: 0; }

/* ---------- Tables ---------- */
table { width: 100%; border-collapse: collapse; margin: 18px 0; font-size: 14px; }
th, td { text-align: left; padding: 10px 14px; border-bottom: 1px solid var(--border); }
th { color: var(--text-dim); font-weight: 600; background: var(--bg-soft); }
tr:hover td { background: rgba(255,255,255,0.02); }

/* ---------- Prose ---------- */
.prose { max-width: 860px; }
.prose h2 { font-size: 24px; margin: 36px 0 12px; }
.prose h3 { font-size: 18px; margin: 26px 0 10px; }
.prose p { margin: 12px 0; color: var(--text-dim); }
.prose p, .prose li { color: var(--text-dim); }
.prose ul, .prose ol { padding-left: 22px; margin: 12px 0; }
.prose li { margin: 6px 0; }

/* ---------- Footer ---------- */
.footer {
  border-top: 1px solid var(--border); padding: 32px 0;
  text-align: center; font-size: 13px; color: var(--text-dim);
}
.footer a { color: var(--text-dim); }
.footer a:hover { color: var(--text); }

/* ---------- Responsive ---------- */
@media (max-width: 720px) {
  .nav-inner { flex-wrap: wrap; }
  .nav-links { gap: 14px; font-size: 14px; }
  .hero { padding: 64px 0 40px; }
  .section { padding: 40px 0; }
}