/* =========================================================
   NAV · barra superior fija (se vuelve opaca al hacer scroll)
   ========================================================= */

.site-nav {
  position: fixed; top: 0; left: 0; right: 0; z-index: 50;
  transition: background .3s, border-color .3s, backdrop-filter .3s;
  border-bottom: 1px solid transparent;
}
.site-nav.is-scrolled {
  background: rgba(var(--rgb-bg), .72);
  backdrop-filter: blur(16px) saturate(140%); -webkit-backdrop-filter: blur(16px) saturate(140%);
  border-color: var(--color-line);
}
.nav-inner { display: flex; align-items: center; justify-content: space-between; height: var(--nav-height); }
.nav-links { display: flex; gap: 32px; font-size: 14px; color: var(--color-text-muted); }
.nav-links a:hover { color: var(--color-text); }

@media (max-width: 720px) {
  .nav-links { display: none; }
  .site-nav .btn-ghost { padding: 9px 14px; font-size: 11px; white-space: nowrap; }
}