:root {
  color-scheme: light;
  --bg: #ffffff;
  --text: #111111;
  --muted: #6b6b6b;
  --line: #d9d9d9;
  --soft: #f5f5f5;
  --panel: #ffffff;
}
* { box-sizing: border-box; }
html {
  width: 100%;
  overflow-x: hidden;
  -webkit-text-size-adjust: 100%;
}
body {
  margin: 0;
  width: 100%;
  overflow-x: hidden;
  min-height: 100vh;
  font-family: ui-sans-serif, -apple-system, BlinkMacSystemFont, "Segoe UI", "Microsoft YaHei", Arial, sans-serif;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
}
a { color: inherit; text-decoration: none; }
a:hover { color: #555; }
img,
video,
canvas,
svg {
  max-width: 100%;
  height: auto;
}
.site-header {
  position: sticky;
  top: 0;
  z-index: 20;
  display: flex;
  align-items: center;
  justify-content: space-between;
  width: 100%;
  padding: 18px 28px;
  border-bottom: 1px solid var(--line);
  background: rgba(255,255,255,.92);
  backdrop-filter: blur(12px);
}
.brand { font-size: 20px; font-weight: 700; letter-spacing: 0; }
.nav { display: flex; gap: 24px; font-size: 15px; }
main { width: 100%; min-width: 0; }
.site-footer {
  border-top: 1px solid var(--line);
  padding: 42px 28px 28px;
  margin-top: 72px;
}
.footer-grid {
  display: grid;
  grid-template-columns: 2fr 1fr 1fr;
  gap: 28px;
  max-width: 1180px;
  margin: 0 auto 42px;
}
.footer-grid p,
.copyright { color: var(--muted); }
.footer-grid a {
  display: block;
  margin-top: 8px;
  color: var(--muted);
}
.copyright {
  display: block;
  max-width: 1180px;
  margin: 0 auto;
  font-size: 14px;
}
@media (max-width: 760px) {
  .site-header {
    align-items: flex-start;
    flex-direction: column;
    gap: 12px;
    padding: 14px 18px;
  }
  .nav {
    width: 100%;
    flex-wrap: wrap;
    gap: 10px 14px;
    font-size: 14px;
  }
  .nav a {
    min-height: 34px;
    display: inline-flex;
    align-items: center;
  }
  .site-footer {
    padding: 32px 18px 24px;
    margin-top: 44px;
  }
  .footer-grid { grid-template-columns: 1fr; }
}