:root {
  --primary: #2563eb;
  --bg: #f8fafc;
  --text: #1e293b;
  --muted: #64748b;
  --border: #e2e8f0;
}

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

body {
  font-family: system-ui, -apple-system, "Segoe UI", Roboto, "PingFang SC", "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--text);
  line-height: 1.7;
}

.hero {
  background: linear-gradient(135deg, #1e3a8a, #2563eb);
  color: #fff;
  text-align: center;
  padding: 64px 20px;
}

.hero h1 {
  font-size: 2.8rem;
  margin-bottom: 8px;
}

.tagline {
  font-size: 1.1rem;
  opacity: 0.95;
  max-width: 640px;
  margin: 0 auto 24px;
}

.actions {
  display: flex;
  gap: 12px;
  justify-content: center;
  flex-wrap: wrap;
}

.btn {
  display: inline-block;
  padding: 10px 22px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  background: #fff;
  color: var(--primary);
}

.btn.primary {
  background: #fbbf24;
  color: #1e3a8a;
}

section {
  max-width: 960px;
  margin: 0 auto;
  padding: 40px 20px;
}

h2 {
  font-size: 1.6rem;
  margin-bottom: 16px;
}

.grid {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 16px;
}

.card {
  background: #fff;
  border: 1px solid var(--border);
  border-radius: 10px;
  padding: 18px;
}

.card h3 {
  margin-bottom: 6px;
}

.download {
  text-align: center;
}

.docs ul {
  list-style: none;
}

.docs li {
  margin: 8px 0;
}

a {
  color: var(--primary);
}

footer {
  text-align: center;
  padding: 24px;
  color: var(--muted);
  font-size: 0.9rem;
}