:root {
    --nav-bg: rgba(255, 255, 255, 0.94);
    --nav-border: rgba(15, 23, 42, 0.08);
    --nav-text: #1f2937;
    --nav-muted: #5b6473;
    --nav-active: #0f172a;
    --nav-accent: #0c6ae0;
    --nav-accent-soft: #eaf3ff;
    --nav-shadow: 0 12px 28px rgba(15, 23, 42, 0.08);
}

.site-header {
    position: sticky;
    top: 0;
    z-index: 1200;
    background: var(--nav-bg);
    backdrop-filter: blur(14px);
    -webkit-backdrop-filter: blur(14px);
    border-bottom: 1px solid var(--nav-border);
    box-shadow: 0 1px 0 rgba(15, 23, 42, 0.03);
}

.header__inner {
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.25rem;
    min-height: 80px;
    position: relative;
}

.brand {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    text-decoration: none;
    color: var(--nav-active);
    font-weight: 800;
    letter-spacing: 0.08em;
}

.brand__logo {
    width: clamp(160px, 18vw, 220px);
    height: auto;
    aspect-ratio: 3 / 1;
    object-fit: contain;
    border-radius: 0;
    transform: translateX(-8px);
}

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

.main-nav__list {
    list-style: none;
    margin: 0;
    padding: 0;
    display: flex;
    align-items: center;
    justify-content: center;
    gap: 1.25rem;
}

.main-nav__link {
    position: relative;
    display: inline-flex;
    align-items: center;
    padding: 0.55rem 0.15rem;
    font-size: 0.95rem;
    font-weight: 600;
    color: var(--nav-muted);
    text-decoration: none;
    transition: color 0.2s ease;
}

.main-nav__link:hover,
.main-nav__link.is-active {
    color: var(--nav-active);
}

.main-nav__link::after {
    content: "";
    position: absolute;
    left: 0;
    bottom: -0.15rem;
    width: 100%;
    height: 2px;
    background: var(--nav-accent);
    border-radius: 999px;
    transform: scaleX(0);
    transform-origin: center;
    transition: transform 0.2s ease;
}

.main-nav__link:hover::after,
.main-nav__link.is-active::after {
    transform: scaleX(1);
}

.header__cta {
    white-space: nowrap;
}

.nav-toggle {
    display: none;
    flex-direction: column;
    justify-content: center;
    gap: 0.28rem;
    width: 2.9rem;
    height: 2.9rem;
    border: 1px solid var(--nav-border);
    background: #fff;
    border-radius: 0.75rem;
    cursor: pointer;
    padding: 0.7rem 0.65rem;
    transition: border-color 0.2s ease, box-shadow 0.2s ease;
}

.nav-toggle:hover {
    border-color: rgba(12, 106, 224, 0.25);
    box-shadow: 0 6px 20px rgba(15, 23, 42, 0.06);
}

.nav-toggle span {
    display: block;
    width: 100%;
    height: 2px;
    background: var(--nav-active);
    border-radius: 999px;
    transition: transform 0.25s ease, opacity 0.25s ease;
}

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

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

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

@media (max-width: 980px) {
    .main-nav {
        position: absolute;
        top: calc(100% + 0.5rem);
        left: 0;
        right: 0;
        display: none;
        justify-content: flex-start;
        background: rgba(255, 255, 255, 0.98);
        border: 1px solid var(--nav-border);
        border-radius: 1rem;
        box-shadow: var(--nav-shadow);
        padding: 1rem;
    }

    .main-nav.is-open {
        display: flex;
    }

    .main-nav__list {
        width: 100%;
        flex-direction: column;
        align-items: flex-start;
        gap: 0.3rem;
    }

    .main-nav__link {
        width: 100%;
        padding: 0.75rem 0.5rem;
        border-radius: 0.65rem;
    }

    .main-nav__link:hover,
    .main-nav__link.is-active {
        background: var(--nav-accent-soft);
    }

    .main-nav__link::after {
        display: none;
    }

    .nav-toggle {
        display: flex;
    }

    .header__cta {
        display: none;
    }
}

@media (max-width: 640px) {
    .header__inner {
        min-height: 72px;
        gap: 0.8rem;
    }

    .brand__logo {
        width: 160px;
        height: auto;
    }
}