:root {
  --bg: #f6f8fc;
  --surface: #ffffff;
  --surface-alt: #f1f5ff;
  --text: #1f2937;
  --muted: #5f6b7a;
  --primary: #3366ff;
  --primary-dark: #2449b8;
  --border: #dbe3f0;
  --shadow: 0 10px 30px rgba(27, 54, 124, 0.08);
}

* {
  box-sizing: border-box;
}

html,
body {
  margin: 0;
  padding: 0;
  font-family: "Microsoft YaHei", "PingFang SC", "Noto Sans SC", sans-serif;
  color: var(--text);
  background: var(--bg);
}

img {
  max-width: 100%;
  height: auto;
  display: block;
}

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

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

.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  background: rgba(255, 255, 255, 0.92);
  border-bottom: 1px solid var(--border);
  backdrop-filter: blur(8px);
}

.header-inner {
  min-height: 72px;
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 20px;
}

.brand {
  display: inline-flex;
  align-items: center;
  gap: 10px;
}

.brand-logo {
  width: 36px;
  height: 36px;
  border-radius: 10px;
}

.brand-name {
  font-size: 20px;
  font-weight: 700;
}

.nav {
  display: flex;
  gap: 22px;
  color: var(--muted);
  font-size: 15px;
}

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

.hero {
  padding: 72px 0 48px;
}

.hero-grid {
  display: grid;
  grid-template-columns: 1.1fr 0.9fr;
  gap: 36px;
  align-items: center;
}

.hero-tag {
  display: inline-block;
  padding: 6px 12px;
  border-radius: 999px;
  background: #e9efff;
  color: var(--primary-dark);
  font-weight: 600;
  font-size: 13px;
}

h1 {
  margin: 14px 0 12px;
  font-size: clamp(34px, 5vw, 50px);
  line-height: 1.15;
}

.hero-content p {
  margin: 0 0 12px;
  color: var(--muted);
  line-height: 1.75;
}

.hero-media img {
  width: 50%;
  margin: 0 auto;
  border-radius: 18px;
  box-shadow: var(--shadow);
  border: 1px solid var(--border);
  background: var(--surface);
}

.section {
  padding: 56px 0;
}

.section-alt {
  background: var(--surface-alt);
}

h2 {
  margin: 0 0 26px;
  font-size: clamp(26px, 4vw, 34px);
}

.feature-grid {
  display: grid;
  grid-template-columns: repeat(3, minmax(0, 1fr));
  gap: 16px;
}

.feature-card {
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: 14px;
  padding: 18px;
  box-shadow: var(--shadow);
}

.feature-card h3 {
  margin: 0 0 8px;
  font-size: 18px;
}

.feature-card p {
  margin: 0;
  color: var(--muted);
  line-height: 1.65;
}

.preview-grid {
  display: grid;
  grid-template-columns: repeat(4, minmax(0, 1fr));
  gap: 14px;
}

.preview-grid img {
  border-radius: 14px;
  border: 1px solid var(--border);
  box-shadow: var(--shadow);
  background: #fff;
}

.site-footer {
  padding: 30px 0 34px;
  border-top: 1px solid var(--border);
  background: #fff;
}

.footer-inner p {
  margin: 8px 0;
  color: var(--muted);
}

.footer-inner p strong {
  color: var(--text);
}

.copyright {
  margin-top: 14px;
  font-size: 14px;
}

@media (max-width: 960px) {
  .hero-grid {
    grid-template-columns: 1fr;
  }

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

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

@media (max-width: 640px) {
  .header-inner {
    flex-direction: column;
    justify-content: center;
    padding: 10px 0;
  }

  .nav {
    gap: 14px;
    font-size: 14px;
    flex-wrap: wrap;
    justify-content: center;
  }

  .hero {
    padding-top: 46px;
  }

  .feature-grid,
  .preview-grid {
    grid-template-columns: 1fr;
  }
}