.site-header {
    --topbar-height: 48px;
    position: sticky;
    top: 0;
    z-index: 50;
    background: rgba(255, 255, 255, 0.95);
    border-bottom: 1px solid rgba(220, 230, 233, 0.85);
    backdrop-filter: blur(16px);
}

.topbar {
    min-height: var(--topbar-height);
    display: flex;
    align-items: center;
    background: #1f5f99;
}

.topbar-inner {
    min-height: var(--topbar-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.topbar-contact {
    display: flex;
    align-items: center;
    gap: 24px;
}

.topbar-contact-link {
    display: inline-flex;
    align-items: center;
    gap: 8px;
    color: rgba(255, 255, 255, 0.92);
    font-size: 0.86rem;
    font-weight: 700;
    transition:
        color 0.2s ease,
        transform 0.2s ease;
}

.topbar-contact-link i {
    color: #ef9408;
    font-size: 0.84rem;
}

.topbar-contact-link:hover,
.topbar-contact-link:focus-visible {
    color: var(--color-white);
    transform: translateY(-1px);
}

.topbar-social {
    display: flex;
    align-items: center;
    gap: 4px;
}

.topbar-social-link {
    width: 44px;
    height: 44px;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    padding: 0;
    line-height: 1;
    border-radius: 50%;
    color: var(--color-white);
    font-size: 0.9rem;
    transition:
        background 0.2s ease,
        color 0.2s ease,
        transform 0.2s ease;
}

.topbar-social-link:hover,
.topbar-social-link:focus-visible {
    background: rgba(255, 255, 255, 0.12);
    color: #ef9408;
    transform: scale(1.05);
}

.topbar-social-link i,
.mobile-social-link i {
    display: block;
    line-height: 1;
}

.header-inner {
    min-height: var(--header-height);
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

/* =========================
   LOGO / BRAND
========================= */

.brand {
    display: flex;
    align-items: center;
    gap: 16px;
    text-decoration: none;
    min-width: 0;
}

.brand-logo {
    width: 78px;
    height: 78px;
    object-fit: contain;
    flex-shrink: 0;
}

.brand-copy {
    display: flex;
    flex-direction: column;
    justify-content: center;
    line-height: 1;
}

.brand-title {
    font-size: 2rem;
    font-weight: 900;
    color: #1f5f99;
    text-transform: uppercase;
    letter-spacing: 1px;
    margin-bottom: 4px;
}

.brand-subtitle {
    font-size: 0.9rem;
    font-weight: 600;
    color: #7b7b7b;
    letter-spacing: 0.5px;
}

/* =========================
   NAVIGATION
========================= */

.site-nav {
    display: flex;
    align-items: center;
}

.mobile-social {
    display: none;
}

.nav-list {
    display: flex;
    align-items: center;
    gap: 4px;
    list-style: none;
}

.nav-item {
    position: relative;
}

.site-nav .nav-link {
    display: block;
    padding: 12px 14px;
    border-radius: var(--radius);
    color: #30434e;
    font-size: 1rem;
    font-weight: 700;
    transition:
        background 0.2s ease,
        color 0.2s ease,
        transform 0.2s ease;
}

.site-nav .nav-link:hover,
.site-nav .nav-link:focus,
.site-nav .nav-link.is-active {
    background: #eaf4f7;
    color: var(--color-blue-800);
}

/* =========================
   MOBILE BUTTON
========================= */

.nav-toggle {
    display: none;
    width: 44px;
    height: 44px;
    border: 1px solid var(--color-line);
    border-radius: var(--radius);
    background: var(--color-white);
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    width: 20px;
    height: 2px;
    margin: 4px auto;
    background: var(--color-blue-900);
}

/* =========================
   TABLET
========================= */

@media (max-width: 980px) {
    .site-header {
        --topbar-height: 48px;
    }

    .topbar-inner {
        gap: 16px;
    }

    .topbar-contact {
        gap: 14px;
    }

    .topbar-contact-link {
        gap: 6px;
        font-size: 0.76rem;
    }

    .nav-toggle {
        display: block;
    }

    .site-nav {
        position: fixed;
        inset: calc(var(--header-height) + var(--topbar-height)) 0 auto;
        max-height: calc(100vh - var(--header-height) - var(--topbar-height));
        overflow-y: auto;
        display: none;
        background: var(--color-white);
        border-bottom: 1px solid var(--color-line);
        box-shadow: var(--shadow-soft);
        padding: 14px 16px 20px;
    }

    .site-nav.is-open {
        display: block;
    }

    .nav-list {
        display: grid;
        gap: 4px;
    }

    .site-nav .nav-link {
        padding: 14px 12px;
    }

    .brand-logo {
        width: 68px;
        height: 68px;
    }

    .brand-title {
        font-size: 1.8rem;
    }
}

/* =========================
   MOBILE
========================= */

@media (max-width: 680px) {
    .site-header {
        --topbar-height: 0px;
    }

    .topbar {
        display: none;
    }

    .header-inner {
        gap: 12px;
    }

    .brand-logo {
        width: 56px;
        height: 56px;
    }

    .brand-title {
        font-size: 1.4rem;
    }

    .brand-subtitle {
        font-size: 0.75rem;
    }

    .site-nav.is-open .mobile-social {
        display: flex;
    }

    .mobile-social {
        align-items: center;
        justify-content: center;
        gap: 10px;
        border-top: 1px solid var(--color-line);
        margin-top: 12px;
        padding-top: 18px;
    }

    .mobile-social-link {
        width: 44px;
        height: 44px;
        display: inline-flex;
        align-items: center;
        justify-content: center;
        padding: 0;
        border: 1px solid var(--color-line);
        border-radius: 50%;
        background: var(--color-soft);
        color: #1f5f99;
        font-size: 1rem;
        line-height: 1;
        transition:
            background 0.2s ease,
            border-color 0.2s ease,
            color 0.2s ease,
            transform 0.2s ease;
    }

    .mobile-social-link:hover,
    .mobile-social-link:focus-visible {
        border-color: #ef9408;
        background: #fff7e9;
        color: #ef9408;
        transform: scale(1.05);
    }
}