:root {
    --carousel-cycle: 15s;
    --fade-duration: 1s;
    --nav-height: 80px;
}

body {
    background-color: #f8f9fa;
    margin: 0;
}

/* ================== Header / Carrusel ================== */
.header {
    position: relative;
    height: 100vh;
    min-height: 420px;
    color: #fff;
    text-align: center;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;

    /* Precarga de imágenes (fuera de vista) */
    background:
        var(--img-base) no-repeat -9999px -9999px,
        var(--img-2) no-repeat -9999px -9999px,
        var(--img-3) no-repeat -9999px -9999px;
}

/* Imagen de fondo base (imagen 1) */
.header::before {
    content: "";
    position: absolute;
    inset: 0;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-image:
        linear-gradient(to bottom, rgba(0, 0, 0, 0.05) 0%, rgba(0, 0, 0, 0.25) 100%),
        var(--img-base);
    z-index: -2;
}

/* Capa animada (se superpone y cambia entre imagen 2 e imagen 3) */
.header::after {
    content: "";
    position: absolute;
    inset: 0;
    background-size: cover;
    background-position: center;
    background-repeat: no-repeat;
    background-image:
        linear-gradient(to bottom, rgba(0, 0, 0, 0.05) 0%, rgba(0, 0, 0, 0.25) 100%),
        var(--img-2);
    z-index: -1;
    opacity: 0;
    animation:
        fadeCycle var(--carousel-cycle) linear infinite,
        changeImage var(--carousel-cycle) steps(1, end) infinite;
}

/* ================== Tipografía interna ================== */
.header h1 {
    font-size: clamp(2.2rem, 6vw, 4.5rem);
    line-height: 1.1;
    margin: 0 0 20px 0;
    text-transform: uppercase;
    font-weight: 900;
    letter-spacing: 1px;
    display: inline-block;
    padding: 0.4em 0.8em;
    color: #fff;
    background: linear-gradient(90deg, #0E0062 0%, #0E0062 100%);
    border-radius: 50px;
    opacity: 0.9;
    box-shadow: 0 4px 15px rgba(14, 0, 98, 0.3);
    backdrop-filter: blur(2px);
}

.breadcrumb-nav {
    font-size: 1.1rem;
    color: #dee2e6;
    margin-top: 15px;
}

.breadcrumb-nav a {
    color: #dee2e6;
    text-decoration: none;
    transition: all 0.3s ease;
}

.breadcrumb-nav a:hover {
    text-decoration: underline;
    color: #fff;
}

.breadcrumb-nav span {
    color: #fff;
    font-weight: 500;
}

/* ================== Animaciones ================== */
/* 
CICLO DE 15s dividido en 3 imágenes = 5s cada una
- Imagen 1 (::before): 0s - 5s
- Imagen 2 (::after): 5s -10s
- Imagen 3 (::after): 10s-15s
*/
@keyframes fadeCycle {
    0%, 33.33%   { opacity: 0; }
    35%          { opacity: 1; }
    65%          { opacity: 1; }
    66.66%       { opacity: 0; }
    68.33%       { opacity: 1; }
    98.33%       { opacity: 1; }
    100%         { opacity: 0; }
}

/* Cambio de imagen sincronizado con los fade-outs */
@keyframes changeImage {
    0%, 66.66% {
        background-image:
            linear-gradient(to bottom, rgba(0,0,0,0.05) 0%, rgba(0,0,0,0.25) 100%),
            var(--img-2);
    }
    66.67%, 100% {
        background-image:
            linear-gradient(to bottom, rgba(0,0,0,0.05) 0%, rgba(0,0,0,0.25) 100%),
            var(--img-3);
    }
}

/* ================== Accesibilidad ================== */
@media (prefers-reduced-motion: reduce) {
    .header::after {
        animation: none;
        opacity: 0;
    }
    .header::before { opacity: 1; }
}

/* ================== Responsive ================== */
@media (max-width: 768px) {
    .header { min-height: 350px; }
    .header h1 {
        font-size: clamp(1.5rem, 4.5vw, 2.8rem);
        margin-bottom: 15px;
    }
    .breadcrumb-nav { font-size: 1rem; }
    :root { --carousel-cycle: 10s; }
}

@media (max-width: 576px) {
    .header { min-height: 300px; }
    .header h1 {
        padding: 0.25em 0.5em;
        border-radius: 35px;
    }
    .breadcrumb-nav { font-size: 0.9rem; }
}

/* ================== Optimizaciones ================== */
.header::before,
.header::after {
    transform: translateZ(0);
    will-change: opacity;
}

@media (-webkit-min-device-pixel-ratio: 2),
(min-resolution: 192dpi) {
    .header::before,
    .header::after {
        image-rendering: -webkit-optimize-contrast;
        image-rendering: crisp-edges;
    }
}

html, body { height: 100%; }

/* Fallback iOS/Safari antiguo */
@supports not (height: 100dvh) {
    html { height: -webkit-fill-available; }
    body { min-height: -webkit-fill-available; }
    .header { height: -webkit-fill-available !important; }
}

/* Navegadores modernos: visual viewport */
@supports (height: 100dvh) {
    .header { height: 100dvh !important; }
}

@media (max-width: 992px) {
    :root { --nav-height: 0px; }
    .header { height: 100svh !important; }
}