.site-header {
    position: sticky;
    top: 0;
    z-index: 100;
    backdrop-filter: blur(18px);
    background: rgba(11, 15, 20, 0.7);
    border-bottom: 1px solid var(--border);
}

[data-theme="light"] .site-header {
    background: rgba(255, 255, 255, 0.8);
}

.nav {
    max-width: 1200px;
    margin: 0 auto;
    padding: 16px 24px;
    display: flex;
    align-items: center;
    justify-content: space-between;
    gap: 24px;
}

.logo {
    font-size: 1.4rem;
    font-weight: 700;
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 20px;
}

.nav-links a {
    color: var(--muted);
    font-weight: 500;
}

.nav-links a.active,
.nav-links a:hover {
    color: var(--text);
}

.nav-toggle {
    display: none;
    background: transparent;
    border: none;
    width: 36px;
    height: 36px;
    position: relative;
    cursor: pointer;
}

.nav-toggle span {
    display: block;
    height: 2px;
    background: var(--text);
    margin: 6px 0;
    transition: transform 0.2s ease;
}

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

.site-footer {
    border-top: 1px solid var(--border);
    padding: 48px 24px 24px;
    background: var(--bg-alt);
}

.footer-grid {
    max-width: 1200px;
    margin: 0 auto;
    display: grid;
    gap: 32px;
    grid-template-columns: repeat(auto-fit, minmax(200px, 1fr));
}

.footer-grid h4 {
    margin-bottom: 12px;
}

.footer-grid ul {
    display: grid;
    gap: 8px;
    color: var(--muted);
}

.footer-meta {
    max-width: 1200px;
    margin: 24px auto 0;
    display: flex;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 12px;
    color: var(--muted);
    font-size: 0.85rem;
}

.theme-toggle {
    border: 1px solid var(--border);
    background: transparent;
    color: var(--text);
}

@media (max-width: 768px) {
    .nav-toggle {
        display: block;
    }

    .nav-links {
        display: none;
    }

    .nav-links.open {
        display: flex;
    }
}