/* =============================================================================
   COVATECK — cabecera compartida (isla.css)
   Medida sobre portfolio.ricoui.com (sep-2026): barra de 60 px dentro de un
   contenedor de 1168 px, transparente arriba; al bajar se vuelve una barra
   blanca flotante con radio 16 y sombra. Logo a la izquierda; a la derecha
   dos enlaces y el botón NIXIE (tinta, píldora, rótulo que sube al pasar).
   El conmutador de tema va en el pie.
   ============================================================================= */

:root {
  --cab-h: 92px;             /* 16 de margen + 60 de barra + aire */
  --cab-h-compacta: 92px;
  --cab-muelle: cubic-bezier(.2, 0, 0, 1);
  --z-cab: 40;
}

.cab {
  position: fixed; top: 16px; left: 0; right: 0;
  z-index: var(--z-cab);
  padding: 0 24px;
  pointer-events: none;
}
.cab-in {
  pointer-events: auto;
  max-width: 1168px; height: 60px;
  margin: 0 auto;
  display: flex; align-items: center; justify-content: space-between; gap: 16px;
  padding: 0 8px;
  border-radius: 16px;
  background: rgba(255,255,255,0);
  box-shadow: 0 8px 30px -12px rgba(15,22,32,0);
  transition: background-color .3s ease, box-shadow .3s ease, padding .3s var(--cab-muelle), transform .35s var(--cab-muelle);
}
.cab.scrolled .cab-in {
  background: var(--superficie-trans, rgba(255,255,255,0.85));
  box-shadow: 0 8px 30px -12px rgba(15,22,32,0.25), 0 0 0 1px rgba(15,22,32,0.05);
  padding: 0 8px 0 16px;
  backdrop-filter: blur(12px);
}

.cab-logo {
  font-family: inherit;
  font-weight: 700; font-size: 17px; letter-spacing: .08em;
  color: var(--tinta); line-height: 1; padding: 10px 8px; border-radius: 8px;
}

.cab-nav { display: flex; align-items: center; margin-left: auto; }
.cab-nav a {
  padding: 6px 14px;
  font-family: inherit;
  font-size: 14px; font-weight: 500;
  color: var(--tinta-2);
  border-radius: 12px;
  /* efecto de mercedes-benz.com.mx: píldora translúcida con sombra corta, 200 ms */
  transition: color .2s ease-in-out, background-color .2s ease-in-out, box-shadow .2s ease-in-out;
}
.cab-nav a:hover { color: var(--tinta); background: var(--cab-pildora, rgba(15,22,32,0.07)); box-shadow: 0 0 2px rgba(0,0,0,0.08), 0 2px 4px rgba(0,0,0,0.08); }
.cab-nav a[aria-current="page"] { color: var(--tinta); }
[data-tema="oscuro"] .cab-nav a:hover { background: rgba(255,255,255,0.10); }

.cab-nixie {
  position: relative; overflow: hidden;
  display: inline-flex; align-items: center; justify-content: center;
  height: 34px; padding: 0 16px;
  border-radius: 999px;
  background: var(--tinta); color: var(--papel);
  font-size: 13px; font-weight: 700; letter-spacing: .06em; text-transform: uppercase;
  transition: transform .3s var(--cab-muelle), box-shadow .3s ease;
}
.cab-nixie:hover { transform: translateY(-1px); box-shadow: 0 8px 18px -8px rgba(15,22,32,0.5); }
.cab-nixie .btn-t, .cab-nixie .btn-c { display: block; transition: transform .45s cubic-bezier(.22,1,.36,1); }
.cab-nixie .btn-c { position: absolute; left: 0; right: 0; top: 50%; text-align: center; transform: translateY(calc(-50% + 210%)); }
.cab-nixie:hover .btn-t { transform: translateY(-210%); }
.cab-nixie:hover .btn-c { transform: translateY(-50%); }
[data-tema="oscuro"] .cab-nixie { background: var(--papel); color: var(--tinta); }

.cab a:focus-visible, .cab button:focus-visible { outline: 2px solid var(--azul); outline-offset: 2px; }

@media (max-width: 900px) {
  :root { --cab-h: 76px; --cab-h-compacta: 76px; }
  .cab { top: 8px; padding: 0 12px; }
  .cab-in { height: 52px; padding: 0 6px; gap: 6px; }
  .cab.scrolled .cab-in { padding: 0 6px 0 10px; }
  .cab-logo { font-size: 15px; letter-spacing: .06em; padding: 8px 4px; }
  .cab-nav { margin-left: auto; }
  .cab-nav a { padding: 8px 10px; font-size: 13px; white-space: nowrap; }
  .cab-nixie { height: 30px; padding: 0 12px; font-size: 12px; }
}
@media (prefers-reduced-motion: reduce) { .cab-in, .cab-cta { transition: none; } }