.site-header {
    position: fixed;
    inset: 0 0 auto;
    z-index: 100;
    border-bottom: 1px solid rgba(var(--color-ash-rgb), var(--nav-border-alpha, 0.08));
    background: rgba(8, 7, 6, 0.82);
    backdrop-filter: blur(18px);
    transition:
        background-color 220ms ease,
        border-color 220ms ease,
        box-shadow 220ms ease;
}

.site-header::after {
    content: "";
    position: absolute;
    left: 0;
    right: 0;
    bottom: -1px;
    height: 1px;
    transform: scaleX(var(--page-progress));
    transform-origin: left;
    background: linear-gradient(90deg, rgba(var(--color-accent-rgb), 0.86), rgba(var(--color-accent-strong-rgb), 0.5));
    opacity: var(--nav-progress-opacity, 0.5);
}

.site-header.is-scrolled {
    border-color: rgba(var(--color-ash-rgb), var(--nav-border-alpha, 0.14));
    background: rgba(8, 7, 6, 0.96);
    box-shadow: 0 16px 42px rgba(0, 0, 0, 0.34);
}

.navbar {
    position: relative;
    display: flex;
    align-items: center;
    justify-content: space-between;
    min-height: 72px;
    gap: 18px;
}

.brand {
    display: inline-flex;
    align-items: center;
    min-width: 0;
    gap: 10px;
}

.brand-mark {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: 0 0 auto;
    width: 38px;
    height: 38px;
    border: 1px solid rgba(var(--color-accent-rgb), 0.36);
    border-radius: var(--radius);
    color: var(--color-soft);
    background:
        linear-gradient(135deg, rgba(var(--color-accent-rgb), 0.48), rgba(var(--color-accent-strong-rgb), 0.2)),
        #17110f;
    box-shadow: inset 0 1px 0 rgba(var(--color-ash-rgb), 0.08);
    font-weight: 800;
}

.brand-copy {
    display: grid;
    min-width: 0;
    gap: 1px;
}

.brand-text {
    color: var(--color-text);
    font-size: 0.98rem;
    font-weight: 800;
    line-height: 1.15;
}

.brand-meta {
    color: var(--color-muted);
    font-size: 0.72rem;
    line-height: 1.25;
}

.nav-menu {
    position: absolute;
    top: calc(100% + 10px);
    left: 0;
    right: 0;
    display: grid;
    gap: 8px;
    padding: 10px;
    border: 1px solid var(--color-line);
    border-radius: var(--radius);
    background: rgba(17, 13, 12, 0.98);
    box-shadow: var(--shadow-soft);
    opacity: 0;
    visibility: hidden;
    pointer-events: none;
    transform: translateY(-8px);
    transition:
        opacity 220ms var(--ease-premium),
        transform 220ms var(--ease-premium),
        visibility 220ms var(--ease-premium);
}

.nav-menu.is-open {
    opacity: 1;
    visibility: visible;
    pointer-events: auto;
    transform: translateY(0);
}

.nav-link,
.nav-cta {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-height: 44px;
    padding: 0 14px;
    border-radius: var(--radius);
    color: var(--color-muted);
    font-size: 0.92rem;
    font-weight: 700;
    transition:
        color 190ms ease,
        background-color 190ms ease,
        border-color 190ms ease,
        transform 190ms ease;
}

.nav-link:hover,
.nav-link.is-active,
.nav-link[aria-current="true"] {
    color: var(--color-text);
    background: rgba(var(--color-ash-rgb), 0.045);
}

.nav-cta {
    border: 1px solid rgba(var(--color-accent-rgb), 0.38);
    color: var(--color-soft);
    background:
        linear-gradient(180deg, rgba(var(--color-accent-rgb), 0.12), rgba(var(--color-accent-rgb), 0.055)),
        rgba(var(--color-ash-rgb), 0.025);
}

.nav-cta:hover {
    border-color: rgba(var(--color-accent-strong-rgb), 0.56);
    background:
        linear-gradient(180deg, rgba(var(--color-accent-rgb), 0.16), rgba(var(--color-accent-strong-rgb), 0.08)),
        rgba(var(--color-ash-rgb), 0.03);
    transform: translateY(-1px);
}

.nav-toggle {
    position: relative;
    display: inline-flex;
    align-items: center;
    justify-content: center;
    flex: 0 0 auto;
    width: 44px;
    height: 44px;
    border: 1px solid var(--color-line);
    border-radius: var(--radius);
    background: rgba(var(--color-ash-rgb), 0.035);
    cursor: pointer;
}

.nav-toggle span {
    position: absolute;
    top: 50%;
    left: 50%;
    width: 18px;
    height: 2px;
    border-radius: 999px;
    background: var(--color-text);
    transition:
        transform 220ms var(--ease-premium),
        opacity 180ms ease;
}

.nav-toggle span:nth-child(1) {
    transform: translate(-50%, calc(-50% - 6px));
}

.nav-toggle span:nth-child(2) {
    transform: translate(-50%, -50%);
}

.nav-toggle span:nth-child(3) {
    transform: translate(-50%, calc(-50% + 6px));
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translate(-50%, -50%) rotate(45deg);
}

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

.nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translate(-50%, -50%) rotate(-45deg);
}

@media (min-width: 960px) {
    .navbar {
        min-height: 80px;
    }

    .nav-toggle {
        display: none;
    }

    .nav-menu {
        position: static;
        display: flex;
        align-items: center;
        width: auto;
        padding: 0;
        border: 0;
        background: transparent;
        box-shadow: none;
        opacity: 1;
        visibility: visible;
        pointer-events: auto;
        transform: none;
    }
}

@media (max-width: 420px) {
    .brand-meta {
        display: none;
    }

    .brand-text {
        font-size: 0.92rem;
    }
}