.site-header {
    position: sticky;
    top: 0;
    z-index: 20;
    padding: 1rem 0;
    background: rgba(var(--color-surface-rgb), 0.78);
    backdrop-filter: blur(18px);
    border-bottom: 1px solid transparent;
    transition: border-color var(--transition), box-shadow var(--transition);
}

.site-header.scrolled {
    border-color: rgba(var(--color-primary-rgb), 0.08);
    box-shadow: 0 8px 24px rgba(10, 30, 70, 0.06);
}

.header-inner {
    display: grid;
    grid-template-columns: auto 1fr auto;
    gap: 1.25rem;
    align-items: center;
}

.brand {
    display: inline-flex;
    align-items: center;
    gap: 0.9rem;
}

.brand-logo {
    height: 36px;
    width: auto;
    display: block;
    object-fit: contain;
}

.brand-text {
    display: flex;
    flex-direction: column;
    gap: 0.15rem;
}

.brand-text strong {
    color: var(--color-primary);
    font-size: 1.05rem;
}

.brand-text span:last-child {
    font-size: 0.78rem;
    color: var(--color-text-muted);
}

.site-nav {
    display: flex;
    justify-content: center;
    flex-wrap: wrap;
    gap: 1.2rem;
}

.nav-list {
    display: flex;
    align-items: center;
    flex-wrap: wrap;
    gap: 1.2rem;
    padding: 0;
    margin: 0;
    list-style: none;
}

.nav-item {
    position: relative;
}

.site-nav a,
.dropdown-toggle {
    font-weight: 600;
    color: var(--color-primary);
    opacity: 0.88;
    font: inherit;
}

.dropdown-toggle {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    border: 0;
    background: transparent;
    cursor: pointer;
    padding: 0;
}

.dropdown-toggle::after {
    content: "";
    width: 0.5rem;
    height: 0.5rem;
    border-right: 2px solid currentColor;
    border-bottom: 2px solid currentColor;
    transform: rotate(45deg) translateY(-1px);
    transition: transform 220ms ease;
}

.site-nav a:hover,
.dropdown-toggle:hover,
.dropdown.open .dropdown-toggle {
    color: var(--color-secondary-dark);
}

.header-actions {
    display: flex;
    gap: 0.75rem;
}

.nav-toggle {
    display: none;
    border: 0;
    background: transparent;
    padding: 0.35rem;
    border-radius: 10px;
}

.nav-toggle span {
    display: block;
    width: 1.45rem;
    height: 2px;
    background: var(--color-primary);
    margin: 0.3rem 0;
    transition: transform var(--transition), opacity var(--transition);
}

.dropdown {
    position: relative;
}

.dropdown-menu {
    position: absolute;
    top: calc(100% + 0.9rem);
    left: 0;
    min-width: 13rem;
    padding: 0.6rem 0;
    margin: 0;
    list-style: none;
    background: var(--color-surface);
    border: 1px solid rgba(var(--color-primary-rgb), 0.08);
    border-radius: var(--radius-xs);
    box-shadow: 0 8px 20px rgba(0, 0, 0, 0.08);
    opacity: 0;
    visibility: hidden;
    transform: translateY(8px);
    transition: opacity 220ms ease, transform 220ms ease, visibility 220ms ease;
    z-index: 30;
}

.dropdown-menu li {
    list-style: none;
}

.dropdown-menu a {
    display: block;
    padding: 0.6rem 1rem;
    white-space: nowrap;
}

.dropdown-menu a:hover,
.dropdown-menu a:focus-visible {
    background: rgba(var(--color-secondary-rgb), 0.08);
    color: var(--color-primary);
}

.dropdown.open .dropdown-menu,
.dropdown:focus-within .dropdown-menu {
    opacity: 1;
    visibility: visible;
    transform: translateY(0);
}

.dropdown.open .dropdown-toggle::after {
    transform: rotate(-135deg) translateY(-1px);
}

@media (min-width: 1121px) {
    .dropdown:hover .dropdown-menu {
        opacity: 1;
        visibility: visible;
        transform: translateY(0);
    }
}

@media (max-width: 1120px) {
    .header-inner {
        grid-template-columns: auto auto;
        grid-template-areas:
            "brand toggle"
            "nav nav"
            "actions actions";
    }

    .brand {
        grid-area: brand;
    }

    .nav-toggle {
        display: inline-block;
        justify-self: end;
        grid-area: toggle;
    }

    .site-nav,
    .header-actions {
        display: none;
    }

    .site-nav {
        grid-area: nav;
        align-items: flex-start;
        padding: 1rem 0 0.25rem;
    }

    .nav-list {
        flex-direction: column;
        align-items: flex-start;
        width: 100%;
        gap: 0.9rem;
    }

    .dropdown-menu {
        position: static;
        min-width: 100%;
        margin-top: 0.65rem;
        box-shadow: none;
    }

    .header-actions {
        grid-area: actions;
        padding-top: 0.25rem;
    }

    .site-header.menu-open .site-nav,
    .site-header.menu-open .header-actions {
        display: flex;
    }
}