/* ==========================================================================
   DIEGO ARC — NAVEGACIÓN GLOBAL FIJA (SISTEMA EDITORIAL)
   ========================================================================== */

.cabecera-sitio {
  position: fixed;
  top: 0;
  left: 0;
  width: 100%;
  display: flex;
  justify-content: space-between;
  align-items: center;
  padding: 1.5rem 4rem;
  box-sizing: border-box;
  z-index: 1000;
  background-color: var(--arc-bg, #FAF8F3);
  border-bottom: 1px solid var(--arc-borde-linea, #eaeaea);
  transition: 
    background-color 0.8s cubic-bezier(0.16, 1, 0.3, 1),
    border-color 0.8s cubic-bezier(0.16, 1, 0.3, 1),
    padding 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.marca {
  font-family: var(--font-titular, 'Space Grotesk', sans-serif);
  font-size: 1.15rem;
  font-weight: 700;
  text-transform: uppercase;
  letter-spacing: -0.02em;
  text-decoration: none;
  color: var(--arc-tinta, #121212);
  transition: color 0.8s cubic-bezier(0.16, 1, 0.3, 1), opacity 0.2s ease;
}

.marca:hover {
  opacity: 0.65;
}

.menu-enlaces {
  list-style: none;
  margin: 0;
  padding: 0;
  display: flex;
  gap: 3rem;
}

.menu-enlaces a {
  font-family: var(--font-tecnica, 'IBM Plex Mono', monospace);
  font-size: 0.75rem;
  text-transform: uppercase;
  letter-spacing: 0.05em;
  text-decoration: none;
  color: var(--arc-texto-secundario, #666666);
  padding-bottom: 0.25rem;
  border-bottom: 1px solid transparent;
  transition: 
    color 0.8s cubic-bezier(0.16, 1, 0.3, 1),
    border-color 0.8s cubic-bezier(0.16, 1, 0.3, 1);
}

.menu-enlaces a:hover {
  color: var(--arc-tinta, #121212);
}

.menu-enlaces a[aria-current="page"] {
  color: var(--arc-tinta, #121212);
  border-bottom-color: var(--arc-tinta, #121212);
}

/* ==========================================================================
   COMPORTAMIENTO EXCLUSIVO DE PORTADA (TRANSPARENTE SOBRE HERO)
   ========================================================================== */

/* Estado inicial sobre la foto del Hero */
body.es-portada .cabecera-sitio {
  background-color: transparent;
  border-bottom-color: transparent;
  padding: 2.5rem 4rem;
}

body.es-portada .cabecera-sitio .marca {
  color: #ffffff;
}

body.es-portada .cabecera-sitio .menu-enlaces a {
  color: rgba(255, 255, 255, 0.8);
}

body.es-portada .cabecera-sitio .menu-enlaces a:hover {
  color: #ffffff;
}

body.es-portada .cabecera-sitio .menu-enlaces a[aria-current="page"] {
  color: #ffffff;
  border-bottom-color: #ffffff;
}

/* Estado al hacer scroll en portada: vuelve a los colores del sistema */
body.es-portada .cabecera-sitio.cabecera-sitio--solida {
  background-color: var(--arc-bg, #FAF8F3);
  border-bottom-color: var(--arc-borde-linea, #eaeaea);
  padding: 1.5rem 4rem;
}

body.es-portada .cabecera-sitio.cabecera-sitio--solida .marca {
  color: var(--arc-tinta, #121212);
}

body.es-portada .cabecera-sitio.cabecera-sitio--solida .menu-enlaces a {
  color: var(--arc-texto-secundario, #666666);
}

body.es-portada .cabecera-sitio.cabecera-sitio--solida .menu-enlaces a:hover {
  color: var(--arc-tinta, #121212);
}

body.es-portada .cabecera-sitio.cabecera-sitio--solida .menu-enlaces a[aria-current="page"] {
  color: var(--arc-tinta, #121212);
  border-bottom-color: var(--arc-tinta, #121212);
}

/* ==========================================================================
   ADAPTACIÓN MÓVIL
   ========================================================================== */

@media (max-width: 820px) {
  .cabecera-sitio {
    padding: 1.25rem;
  }
  
  body.es-portada .cabecera-sitio {
    padding: 1.5rem 1.25rem;
  }

  body.es-portada .cabecera-sitio.cabecera-sitio--solida {
    padding: 1.25rem;
  }

  .menu-enlaces {
    gap: 1.5rem;
  }
}

@media (prefers-reduced-motion: reduce) {
  .cabecera-sitio,
  .marca,
  .menu-enlaces a {
    transition: none !important;
  }
}