.site-header {
  position: sticky;
  top: 0;
  z-index: 30;
  border-bottom: 1px solid var(--line);
  background: color-mix(in oklab, var(--surface) 90%, white 10%);
  backdrop-filter: blur(8px);
}
.header-inner {
  display: flex;
  align-items: center;
  justify-content: space-between;
  gap: 0.8rem;
  padding: 0.8rem 0;
}
.brand {
  display: flex;
  align-items: center;
  gap: 0.55rem;
  text-decoration: none;
  font-weight: 800;
}
.brand img { width: 34px; height: 34px; border-radius: 8px; }
.nav-wrap { display: flex; align-items: center; gap: 0.8rem; }
.main-nav { display: flex; gap: 0.35rem; flex-wrap: wrap; }
.nav-link {
  text-decoration: none;
  border-radius: 999px;
  padding: 0.46rem 0.72rem;
  color: var(--muted);
  transition: all var(--transition);
}
.nav-link.active, .nav-link:hover {
  background: var(--accent-soft);
  color: var(--accent-strong);
}
.control-group {
  display: inline-flex;
  border: 1px solid var(--line);
  border-radius: 999px;
  overflow: hidden;
  background: var(--surface);
}
.control-group button, .control-group a {
  border: 0;
  background: transparent;
  padding: 0.38rem 0.66rem;
  font-size: 0.86rem;
  text-decoration: none;
  color: var(--muted);
  cursor: pointer;
}
.control-group .active { background: var(--accent-soft); color: var(--accent-strong); font-weight: 700; }
.menu-toggle {
  display: none;
  border: 1px solid var(--line);
  background: var(--surface);
  border-radius: 10px;
  width: 38px;
  height: 38px;
}
.site-footer {
  margin-top: 2.5rem;
  border-top: 1px solid var(--line);
  background: var(--surface);
}
.footer-grid {
  display: grid;
  gap: 1rem;
  grid-template-columns: 2fr 1fr 1.2fr;
  padding: 1.4rem 0;
}
.footer-grid a, .footer-grid p { display: block; margin: 0.28rem 0; color: var(--muted); text-decoration: none; }
.footer-bottom { color: var(--muted); padding: 0 0 1.2rem; }

@media (max-width: 900px) {
  .menu-toggle { display: inline-flex; align-items: center; justify-content: center; }
  .main-nav { display: none; }
  .main-nav.open {
    display: grid;
    position: absolute;
    left: 4vw;
    right: 4vw;
    top: 64px;
    background: var(--surface);
    border: 1px solid var(--line);
    border-radius: 14px;
    padding: 0.6rem;
    box-shadow: var(--shadow);
  }
  .header-inner { position: relative; }
  .footer-grid { grid-template-columns: 1fr; }
}