:root {
  --bg: #f7f8fa;
  --fg: #1f2329;
  --muted: #6b7280;
  --brand: #2f6fed;
  --brand-fg: #ffffff;
  --border: #e5e7eb;
  --card: #ffffff;
}

* { box-sizing: border-box; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Microsoft YaHei", sans-serif;
  background: var(--bg);
  color: var(--fg);
  line-height: 1.6;
}

.site-header {
  display: flex;
  align-items: center;
  justify-content: space-between;
  padding: 14px 24px;
  background: var(--card);
  border-bottom: 1px solid var(--border);
}

.logo { font-weight: 700; color: var(--brand); }

.site-header nav a {
  margin-left: 16px;
  color: var(--muted);
  text-decoration: none;
}

.site-header nav a.active,
.site-header nav a:hover { color: var(--fg); }

.container {
  max-width: 880px;
  margin: 0 auto;
  padding: 48px 24px;
}

.hero h1 { font-size: 32px; margin-bottom: 8px; }
.lead { color: var(--muted); margin-bottom: 24px; }

.btn {
  background: var(--brand);
  color: var(--brand-fg);
  border: none;
  border-radius: 8px;
  padding: 10px 18px;
  font-size: 15px;
  cursor: pointer;
}
.btn:hover { filter: brightness(0.95); }

.cta-wrap { margin-top: 24px; }
.cta {
  color: var(--brand);
  text-decoration: none;
  font-weight: 600;
}

.site-footer {
  text-align: center;
  color: var(--muted);
  font-size: 13px;
  padding: 24px;
}