/* =========================================================
   Acuaria — Site header
   ========================================================= */

.site-header {
    position: fixed;
    top: 0;
    left: 0;
    right: 0;
    z-index: var(--z-header);
    padding: var(--space-4) 0;
    transition: background var(--transition-base), backdrop-filter var(--transition-base), padding var(--transition-base), box-shadow var(--transition-base);
}

.site-header--scrolled {
    background: rgba(13, 27, 42, 0.85);
    backdrop-filter: blur(16px) saturate(1.4);
    -webkit-backdrop-filter: blur(16px) saturate(1.4);
    padding: var(--space-3) 0;
    box-shadow: 0 4px 32px rgba(13, 27, 42, 0.18);
    border-bottom: 1px solid rgba(72, 217, 196, 0.08);
}

.site-header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: var(--space-6);
}

.site-header__brand {
    display: block;
    position: relative;
    flex-shrink: 0;
    transition: transform var(--transition-fast);
}

.site-header__brand:hover {
    transform: scale(1.02);
}

.site-header__logo {
    height: 54px;
    width: auto;
    display: block;
}

.site-header__logo--light {
    display: none;
}

.site-nav {
    flex: 1;
    display: flex;
    justify-content: center;
}

.site-nav__close {
    display: none;
    color: var(--color-white);
    padding: var(--space-3);
    border-radius: var(--radius-md);
}

.site-nav__list {
    display: flex;
    gap: var(--space-8);
    align-items: center;
}

.site-nav__link {
    position: relative;
    font-size: var(--font-size-sm);
    font-weight: var(--font-weight-medium);
    color: rgba(242, 237, 228, 0.75);
    padding: var(--space-2) 0;
    transition: color var(--transition-fast);
    display: inline-flex;
    align-items: center;
    gap: var(--space-2);
}

.site-nav__link:hover,
.site-nav__link.is-active {
    color: var(--color-white);
}

.site-nav__link::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 50%;
    transform: translateX(-50%) scaleX(0);
    width: 20px;
    height: 2px;
    background: var(--color-teal-light);
    border-radius: 2px;
    transition: transform var(--transition-base);
}

.site-nav__link:hover::after,
.site-nav__link.is-active::after {
    transform: translateX(-50%) scaleX(1);
}

.site-nav__link--ai {
    background: linear-gradient(135deg, rgba(27, 184, 160, 0.15), rgba(255, 107, 53, 0.15));
    padding: var(--space-2) var(--space-4);
    border-radius: var(--radius-pill);
    border: 1px solid rgba(72, 217, 196, 0.3);
    color: var(--color-teal-light);
    font-weight: var(--font-weight-semibold);
}

.site-nav__link--ai:hover,
.site-nav__link--ai.is-active {
    background: linear-gradient(135deg, rgba(27, 184, 160, 0.3), rgba(255, 107, 53, 0.3));
    border-color: rgba(72, 217, 196, 0.6);
    color: var(--color-white);
}

.site-nav__link--ai::after {
    display: none;
}

.ia-dot {
    width: 6px;
    height: 6px;
    border-radius: 50%;
    background: var(--color-teal-light);
    box-shadow: 0 0 8px var(--color-teal-light);
    animation: pulseIaDot 2s ease-in-out infinite;
}

@keyframes pulseIaDot {
    0%, 100% { opacity: 1; transform: scale(1); }
    50% { opacity: 0.5; transform: scale(1.4); }
}

.site-header__cta {
    flex-shrink: 0;
}

.site-header__burger {
    display: none;
    flex-direction: column;
    gap: 5px;
    padding: var(--space-3);
    width: 44px;
    height: 44px;
    align-items: center;
    justify-content: center;
}

.site-header__burger span {
    display: block;
    width: 24px;
    height: 2px;
    background: var(--color-white);
    border-radius: 2px;
    transition: transform var(--transition-base), opacity var(--transition-base);
}

/* ---------- Mobile ---------- */
@media (max-width: 1024px) {
    .site-nav {
        position: fixed;
        inset: 0;
        background: rgba(13, 27, 42, 0.98);
        backdrop-filter: blur(24px);
        -webkit-backdrop-filter: blur(24px);
        flex-direction: column;
        justify-content: center;
        align-items: center;
        padding: var(--space-8);
        opacity: 0;
        visibility: hidden;
        transform: translateY(-20px);
        transition: opacity var(--transition-base), visibility var(--transition-base), transform var(--transition-base);
        z-index: calc(var(--z-header) + 1);
    }

    .site-nav.is-open {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }

    .site-nav__close {
        display: block;
        position: absolute;
        top: var(--space-6);
        right: var(--space-6);
    }

    .site-nav__list {
        flex-direction: column;
        gap: var(--space-6);
        font-size: 1.5rem;
    }

    .site-nav__link {
        font-size: 1.25rem;
    }

    .site-header__burger {
        display: flex;
    }

    .site-header__cta {
        display: none;
    }
}

@media (max-width: 480px) {
    .site-header__logo {
        height: 44px;
    }
}