/* ── Site Header ─────────────────────────────────── */
.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    background: color-mix(in srgb, var(--color-primary) 94%, transparent);
    backdrop-filter: blur(16px);
    -webkit-backdrop-filter: blur(16px);
    border-bottom: 1px solid color-mix(in srgb, var(--color-white) 7%, transparent);
}

.site-header__inner {
    width: min(calc(100% - 3rem), var(--container-width));
    margin: 0 auto;
    min-height: 72px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 1.5rem;
}

/* ── Brand ───────────────────────────────────────── */
.site-brand {
    display: inline-flex;
    align-items: center;
    gap: 0.85rem;
    text-decoration: none;
}

.site-brand__logo {
    width: auto;
    height: 2.4rem;
    /* Invert logo to white on dark header */
    filter: brightness(0) invert(1);
}

.site-brand__logo--admin {
    height: 2rem;
    filter: none;
}

/* ── Navigation ──────────────────────────────────── */
.site-nav ul {
    display: flex;
    align-items: center;
    gap: 0.1rem;
    margin: 0;
    padding: 0;
    list-style: none;
}

.site-nav a {
    display: inline-flex;
    align-items: center;
    min-height: 42px;
    padding: 0 1rem;
    color: color-mix(in srgb, var(--color-dark-text) 72%, transparent);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.9rem;
    letter-spacing: 0.03em;
    transition: color 0.15s ease;
    position: relative;
}

.site-nav a:hover,
.site-nav a.active {
    color: var(--color-white);
}

.site-nav a.active::after {
    content: "";
    position: absolute;
    left: 1rem;
    right: 1rem;
    bottom: 0.3rem;
    height: 2px;
    border-radius: 999px;
    background: var(--color-accent);
}

/* ── Language switcher ───────────────────────────── */
.site-nav__language-switcher {
    display: inline-flex;
    align-items: center;
    gap: 0.25rem;
    margin-left: 0.6rem;
    padding-left: 0.6rem;
    border-left: 1px solid color-mix(in srgb, var(--color-white) 12%, transparent);
}

.site-nav__lang-link {
    display: inline-flex;
    align-items: center;
    justify-content: center;
    min-width: 36px;
    min-height: 36px;
    padding: 0.2rem;
    border-radius: 4px;
    transition: background 0.15s ease;
}

.site-nav__lang-link:hover {
    background: color-mix(in srgb, var(--color-white) 10%, transparent);
}

.site-nav__lang-link.active {
    background: color-mix(in srgb, var(--color-accent) 20%, transparent);
}

.site-nav__flag {
    display: block;
    width: 22px;
    height: 22px;
    border-radius: 3px;
    border: 1px solid color-mix(in srgb, var(--color-white) 15%, transparent);
    background-size: cover;
    background-repeat: no-repeat;
    background-position: center;
}

.site-nav__flag--cz {
    background-image: url("/images/flags/cz.svg");
}

.site-nav__flag--en {
    background-image: url("/images/flags/gb.svg");
}

.site-nav__sr-only {
    position: absolute;
    width: 1px;
    height: 1px;
    padding: 0;
    margin: -1px;
    overflow: hidden;
    clip: rect(0, 0, 0, 0);
    white-space: nowrap;
    border: 0;
}

/* ── Admin variant ───────────────────────────────── */
.site-header--admin {
    background: color-mix(in srgb, var(--color-surface) 96%, transparent);
    border-bottom-color: var(--color-border);
}

.site-header--admin .site-nav a {
    color: var(--color-text-soft);
}

.site-header--admin .site-nav a:hover,
.site-header--admin .site-nav a.active {
    color: var(--color-primary);
}

.site-header--admin .site-brand__logo {
    filter: none;
}

.site-header--admin .site-nav__language-switcher {
    border-left-color: var(--color-border);
}

.site-header--admin .site-nav__lang-link:hover {
    background: color-mix(in srgb, var(--color-primary) 6%, transparent);
}

.site-header--admin .site-nav__lang-link.active {
    background: color-mix(in srgb, var(--color-accent) 8%, transparent);
}

.site-header--admin .site-nav__flag {
    border-color: color-mix(in srgb, var(--color-primary) 15%, transparent);
}

/* ── Mobile menu toggle ──────────────────────────── */
.menu-toggle {
    display: none;
    min-height: 40px;
    padding: 0 0.9rem;
    border: 1px solid color-mix(in srgb, var(--color-white) 20%, transparent);
    border-radius: 4px;
    background: transparent;
    color: var(--color-white);
    font: inherit;
    font-weight: 700;
    font-size: 0.85rem;
    letter-spacing: 0.05em;
    cursor: pointer;
    transition: background 0.15s ease;
}

.menu-toggle:hover {
    background: color-mix(in srgb, var(--color-white) 8%, transparent);
}

.site-header--admin .menu-toggle {
    border-color: var(--color-border);
    color: var(--color-text);
    background: transparent;
}

.site-header--admin .menu-toggle:hover {
    background: color-mix(in srgb, var(--color-primary) 5%, transparent);
}

@media (max-width: 860px) {
    .site-header__inner {
        flex-wrap: wrap;
        padding: 0.8rem 0;
        min-height: auto;
    }

    .menu-toggle {
        display: inline-flex;
        align-items: center;
    }

    .site-nav {
        display: none;
        width: 100%;
        border-top: 1px solid color-mix(in srgb, var(--color-white) 8%, transparent);
        padding-top: 0.5rem;
        padding-bottom: 0.5rem;
    }

    .site-header--admin .site-nav {
        border-top-color: var(--color-border);
    }

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

    .site-nav ul {
        flex-direction: column;
        align-items: stretch;
    }

    .site-nav a {
        width: 100%;
        justify-content: center;
    }

    .site-nav__language-switcher {
        margin-left: 0;
        padding-left: 0;
        border-left: 0;
        justify-content: center;
        padding-top: 0.5rem;
        border-top: 1px solid color-mix(in srgb, var(--color-white) 8%, transparent);
    }

    .site-header--admin .site-nav__language-switcher {
        border-top-color: var(--color-border);
    }
}