/* Encabezado de Kern (2026-10-30): marca «kern · por π Pi Management» con los anillos del núcleo,
 * barra azul núcleo. Sólo .header del sitio público; el panel no usa .header. ---------- */
.header { background: rgba(15,26,51,.95); }
.header.is-stuck { border-color: rgba(255,255,255,.06); box-shadow: 0 6px 24px rgba(0,0,0,.18); }
.brand--kern { gap: .7rem; color: #fff; }
.brand--kern .brand__anillos { width: 38px; height: 38px; flex: none; color: #fff; }
.brand--kern .brand__txt b { color: #fff; font-size: 1.55rem; font-weight: 700; letter-spacing: -.02em; }
.brand--kern .brand__txt small { letter-spacing: .04em; text-transform: none; font-size: .7rem; color: #aab6cc; margin-top: 3px; }
.brand--kern .brand__txt small i { font-style: normal; color: #ff8a8f; font-weight: 700; }
.header .nav__links > li > a { color: #dbe2ee; }
.header .nav__links > li > a:hover { color: #fff; background: rgba(255,255,255,.08); }
.header .theme-toggle, .header .nav__toggle { color: #dbe2ee; background: transparent; border-color: rgba(255,255,255,.22); }
.dropdown--kern { min-width: 560px; display: grid; grid-template-columns: 1fr 1fr; gap: 2px; }
@media (max-width: 1160px){
  .header .nav__links.open > li > a { color: var(--ink-2); }
  .dropdown--kern { min-width: 0; grid-template-columns: 1fr; }
  .nav__links.open .has-menu.open .dropdown--kern { display: grid; }
}