:root {
  --bg: #f5f7fb;
  --text: #1f2937;
  --muted: #6b7280;
  --primary: #1463ff;
  --card: #ffffff;
  --line: #e5e7eb;
}

* {
  box-sizing: border-box;
}

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

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

.container {
  width: min(1120px, 92vw);
  margin: 0 auto;
}

.header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.95);
  border-bottom: 1px solid var(--line);
  backdrop-filter: blur(8px);
}

.nav {
  display: flex;
  align-items: center;
  justify-content: space-between;
  min-height: 68px;
}

.logo {
  font-weight: 700;
}

.menu {
  display: flex;
  gap: 20px;
}

.menu a {
  color: var(--muted);
  font-size: 14px;
}

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

.menu-toggle {
  display: none;
  border: 1px solid var(--line);
  border-radius: 8px;
  background: #fff;
  padding: 8px 12px;
}

.hero {
  background: linear-gradient(135deg, #0f295d 0%, #1463ff 100%);
  color: #fff;
  padding: 88px 0 96px;
}

.sub-title {
  margin: 0;
  letter-spacing: 0.08em;
  font-size: 12px;
  opacity: 0.9;
}

.hero h1 {
  margin: 12px 0 16px;
  font-size: clamp(28px, 4vw, 42px);
  line-height: 1.2;
}

.hero-desc {
  max-width: 700px;
  margin-bottom: 28px;
  color: rgba(255, 255, 255, 0.9);
}

.btn {
  display: inline-block;
  background: #fff;
  color: #12398e;
  font-weight: 600;
  border-radius: 10px;
  padding: 12px 20px;
}

.section {
  padding: 68px 0;
}

.section.alt {
  background: #f0f3fa;
}

h2 {
  margin: 0 0 28px;
  font-size: clamp(22px, 3vw, 30px);
}

h2 span {
  display: block;
  margin-top: 4px;
  color: var(--muted);
  font-size: 13px;
  font-weight: 500;
  letter-spacing: 0.06em;
}

.cards,
.case-grid,
.news-list {
  display: grid;
  gap: 18px;
}

.cards {
  grid-template-columns: repeat(2, minmax(0, 1fr));
}

.case-grid {
  grid-template-columns: repeat(3, minmax(0, 1fr));
}

.card,
.case-item,
.news-item,
.download-item {
  background: var(--card);
  border: 1px solid var(--line);
  border-radius: 12px;
  padding: 20px;
}

.card h3,
.case-item h3,
.news-item h3,
.download-item h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.card p,
.case-item p,
.news-item p,
.download-item p {
  margin: 0;
  color: var(--muted);
}

.download-list {
  display: grid;
  grid-template-columns: repeat(2, minmax(0, 1fr));
  gap: 18px;
}

.download-btn {
  display: inline-block;
  margin-top: 14px;
  padding: 9px 14px;
  border-radius: 8px;
  border: 1px solid #c7d2fe;
  color: #1e40af;
  background: #eef2ff;
  font-size: 14px;
  font-weight: 600;
}

.download-btn:hover {
  background: #dbeafe;
}

.download-hint {
  margin: 14px 0 0;
  color: var(--muted);
  font-size: 14px;
}

.tag-list {
  margin: 24px 0 0;
  padding: 0;
  list-style: none;
  display: flex;
  flex-wrap: wrap;
  gap: 10px;
}

.tag-list li {
  background: #eaf0ff;
  color: #1a4cbc;
  border-radius: 999px;
  padding: 8px 14px;
  font-size: 13px;
}

.news-item time {
  display: inline-block;
  margin-bottom: 8px;
  color: #4b5563;
  font-weight: 600;
}

.footer {
  background: #0f172a;
  color: #e5e7eb;
  padding: 52px 0;
}

.footer h2 {
  margin-bottom: 8px;
}

.footer p {
  margin: 0;
  color: #cbd5e1;
}

.footer-links {
  margin-top: 18px;
  display: flex;
  flex-wrap: wrap;
  gap: 14px;
}

.footer-links a {
  color: #bfdbfe;
}

.copyright {
  margin-top: 20px;
  font-size: 13px;
}

@media (max-width: 900px) {
  .cards,
  .case-grid,
  .download-list {
    grid-template-columns: 1fr;
  }
}

@media (max-width: 760px) {
  .menu-toggle {
    display: inline-block;
  }

  .menu {
    display: none;
    position: absolute;
    top: 68px;
    left: 0;
    right: 0;
    padding: 14px 4vw 18px;
    background: #fff;
    border-bottom: 1px solid var(--line);
    flex-direction: column;
    gap: 12px;
  }

  .menu.is-open {
    display: flex;
  }
}