/* ── Top bar (logo + brand) ── */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: rgba(247, 248, 245, 0.9);
    backdrop-filter: blur(12px);
    -webkit-backdrop-filter: blur(12px);
    border-bottom: 1px solid rgba(83, 101, 60, 0.12);
    transition: box-shadow var(--t-fast);
}

.site-header.scrolled {
    box-shadow: var(--shadow-soft);
}

/* ── Header inner structure ── */
.header-inner {
    display: flex;
    flex-direction: column;
}

/* Top bar: logo + brand name + optional social quick links */
.header-top {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0.75rem var(--sp-4);
    border-bottom: 1px solid rgba(83, 101, 60, 0.08);
    position: relative;
}

.header-social {
    position: absolute;
    right: var(--sp-4);
    display: flex;
    gap: var(--sp-2);
    align-items: center;
}

.header-social a {
    font-size: var(--fs-xs);
    font-weight: var(--fw-bold);
    letter-spacing: 0.06em;
    color: var(--color-olive-soft);
    transition: color var(--t-fast);
}

.header-social a:hover {
    color: var(--color-olive-deep);
}

/* ── Brand ── */
.brand {
    display: flex;
    align-items: center;
    gap: var(--sp-3);
    text-decoration: none;
    color: var(--color-ink-green);
}

.logo-img {
    height: 72px;
    width: auto;
    object-fit: contain;
}

.brand-name {
    font-family: var(--font-serif);
    font-size: var(--fs-2xl);
    font-weight: var(--fw-bold);
    letter-spacing: 0.01em;
    line-height: var(--lh-tight);
    color: var(--color-ink-green);
}

/* ── Navigation bar ── */
.header-nav {
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    background: var(--color-olive-deep);
}

.nav-menu {
    display: flex;
    align-items: center;
    gap: 0;
    width: 100%;
    max-width: var(--container);
    padding-inline: var(--sp-4);
}

.nav-menu a {
    display: inline-block;
    padding: 0.8rem 1.1rem;
    font-family: var(--font-sans);
    font-size: var(--fs-sm);
    font-weight: var(--fw-medium);
    letter-spacing: 0.04em;
    color: rgba(255, 255, 255, 0.88);
    position: relative;
    transition: color var(--t-fast), background var(--t-fast);
}

.nav-menu a::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 1.1rem;
    right: 1.1rem;
    height: 2px;
    background: var(--color-gold);
    transform: scaleX(0);
    transition: transform var(--t-base);
    border-radius: 2px;
}

.nav-menu a:hover,
.nav-menu a.active {
    color: var(--color-white);
    background: rgba(255, 255, 255, 0.08);
}

.nav-menu a:hover::after,
.nav-menu a.active::after {
    transform: scaleX(1);
}

/* ── Mobile toggle ── */
.menu-toggle {
    display: none;
    align-items: center;
    gap: 0.4rem;
    padding: 0.55rem 0.9rem;
    background: var(--color-olive-main);
    color: var(--color-white);
    border-radius: var(--radius-sm);
    font-size: var(--fs-sm);
    font-weight: var(--fw-bold);
    position: absolute;
    right: var(--sp-4);
    top: 50%;
    transform: translateY(-50%);
    transition: background var(--t-fast);
}

.menu-toggle:hover {
    background: var(--color-olive-deep);
}

/* Mobile hamburger icon */
.menu-toggle-icon {
    display: flex;
    flex-direction: column;
    gap: 4px;
    width: 18px;
}

.menu-toggle-icon span {
    height: 2px;
    background: currentColor;
    border-radius: 2px;
    transition: transform var(--t-fast), opacity var(--t-fast);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-icon span:nth-child(1) {
    transform: translateY(6px) rotate(45deg);
}

.menu-toggle[aria-expanded="true"] .menu-toggle-icon span:nth-child(2) {
    opacity: 0;
}

.menu-toggle[aria-expanded="true"] .menu-toggle-icon span:nth-child(3) {
    transform: translateY(-6px) rotate(-45deg);
}

/* ── Mobile nav ── */
@media (max-width: 900px) {
    .header-top {
        justify-content: flex-start;
        padding-right: calc(var(--sp-4) + 100px);
    }

    .brand-name {
        font-size: var(--fs-lg);
    }

    .logo-img {
        height: 52px;
    }

    .header-social {
        display: none;
    }

    .menu-toggle {
        display: flex;
    }

    .header-nav {
        padding: 0;
    }

    .nav-menu {
        display: none;
        flex-direction: column;
        align-items: flex-start;
        position: absolute;
        top: 100%;
        left: 0;
        right: 0;
        background: var(--color-olive-deep);
        padding: var(--sp-2) 0;
        box-shadow: var(--shadow-mid);
        z-index: 200;
    }

    .nav-menu.open {
        display: flex;
    }

    .nav-menu a {
        width: 100%;
        padding: 0.9rem var(--sp-4);
        border-bottom: 1px solid rgba(255, 255, 255, 0.06);
    }

    .nav-menu a::after {
        display: none;
    }
}