:root {
  --brand: #2a5bd7;
  --brand-dark: #1e44a8;
  --ink: #1a1f2b;
  --muted: #5b6472;
  --line: #e6e9ef;
  --bg-alt: #f6f8fc;
  --max: 1080px;
}

* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  font-family: -apple-system, BlinkMacSystemFont, "Segoe UI", "PingFang SC",
    "Hiragino Sans GB", "Microsoft YaHei", sans-serif;
  color: var(--ink);
  line-height: 1.6;
  background: #fff;
}

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

/* Header */
.site-header {
  position: sticky;
  top: 0;
  z-index: 10;
  background: rgba(255, 255, 255, 0.92);
  backdrop-filter: saturate(180%) blur(8px);
  border-bottom: 1px solid var(--line);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  height: 64px;
}

.brand {
  display: flex;
  align-items: center;
  gap: 10px;
  text-decoration: none;
  color: var(--ink);
}

.brand-mark {
  display: inline-grid;
  place-items: center;
  width: 36px;
  height: 36px;
  border-radius: 8px;
  background: var(--brand);
  color: #fff;
  font-weight: 700;
  font-size: 13px;
}

.brand-name { font-weight: 600; }

.menu a {
  margin-left: 24px;
  color: var(--muted);
  text-decoration: none;
  font-size: 15px;
}

.menu a:hover { color: var(--brand); }

/* Hero */
.hero {
  background: linear-gradient(160deg, #eef3ff 0%, #fff 70%);
  padding: 96px 0;
  text-align: center;
}

.hero h1 {
  font-size: clamp(28px, 5vw, 44px);
  margin: 0 0 16px;
  letter-spacing: -0.5px;
}

.hero-sub {
  color: var(--muted);
  font-size: 18px;
  max-width: 620px;
  margin: 0 auto 28px;
}

.btn {
  display: inline-block;
  background: var(--brand);
  color: #fff;
  padding: 12px 28px;
  border-radius: 8px;
  text-decoration: none;
  font-weight: 600;
  transition: background 0.15s ease;
}

.btn:hover { background: var(--brand-dark); }

/* Sections */
.section { padding: 72px 0; }
.section-alt { background: var(--bg-alt); }

.section h2 {
  font-size: 28px;
  margin: 0 0 24px;
}

.lead {
  color: var(--muted);
  font-size: 17px;
  max-width: 720px;
}

/* Cards */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 20px;
}

.card {
  background: #fff;
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 24px;
}

.card h3 { margin: 0 0 8px; font-size: 18px; }
.card p { margin: 0; color: var(--muted); }

/* Contact */
.contact-list {
  list-style: none;
  padding: 0;
  margin: 0;
  font-size: 16px;
}

.contact-list li { margin-bottom: 10px; }
.contact-list em { color: var(--muted); font-size: 13px; }

/* Footer */
.site-footer {
  border-top: 1px solid var(--line);
  padding: 28px 0;
  text-align: center;
  color: var(--muted);
  font-size: 14px;
}

.site-footer p { margin: 4px 0; }

.beian a {
  color: var(--muted);
  text-decoration: none;
}

.beian a:hover { color: var(--brand); }