.app-background {
    position: fixed;
    inset: 0;
    background: var(--app-background);
    pointer-events: none;
    z-index: 0;
}

.app-shell {
    position: relative;
    z-index: 1;
    max-width: var(--max-content);
    margin: 0 auto;
    padding: 20px 20px 34px;
}

.top-nav {
    position: sticky;
    top: 12px;
    z-index: 50;
    display: flex;
    justify-content: space-between;
    align-items: center;
    gap: var(--space-lg);
    padding: 0.86rem 1.1rem;
    border: 1px solid color-mix(in srgb, var(--surface-tint), transparent 89%);
    background: var(--nav-background);
    backdrop-filter: blur(18px) saturate(122%);
    border-radius: 20px;
    box-shadow: var(--shadow-soft);
    transition: border-color 260ms ease, box-shadow 260ms ease, background 260ms ease;
}

.top-nav:hover {
    border-color: color-mix(in srgb, var(--accent), transparent 65%);
    box-shadow: var(--shadow-soft), 0 0 0 1px color-mix(in srgb, var(--accent), transparent 82%);
}

.brand-wrap {
    display: flex;
    align-items: center;
    gap: 0.72rem;
}

.brand-logo {
    width: 40px;
    height: 40px;
}

.brand-name {
    margin: 0;
    font-size: 1.03rem;
    font-weight: 650;
    letter-spacing: 0.02em;
    color: var(--text-primary);
}

.brand-subtitle {
    margin: 0;
    font-size: 0.75rem;
    color: var(--text-muted);
}

.nav-links {
    display: flex;
    align-items: center;
    gap: 0.32rem;
}

.nav-links a {
    display: inline-flex;
    align-items: center;
    gap: 0.38rem;
    text-decoration: none;
    font-weight: 540;
    font-size: 0.84rem;
    letter-spacing: 0.01em;
    color: var(--text-secondary);
    padding: 8px 11px;
    border-radius: 999px;
    transition: color 200ms ease, background 200ms ease, transform 220ms ease,
    box-shadow 220ms ease;
}

.nav-links a:hover {
    color: var(--text-primary);
    background: color-mix(in srgb, var(--surface-tint), transparent 92%);
    transform: translateY(-1px);
}

.nav-links a.is-active {
    color: var(--accent-contrast-strong);
    background: linear-gradient(115deg, var(--accent), var(--accent-2));
    box-shadow: var(--glow-accent);
}

.nav-links .nav-github {
    border: 1px solid var(--border);
    background: color-mix(in srgb, var(--surface-tint), transparent 95%);
}

.main-content {
    margin-top: 2.5rem;
    animation: fade-up 580ms cubic-bezier(0.22, 1, 0.36, 1);
}

.site-footer {
    margin-top: 3.2rem;
    padding: 0.4rem 0.2rem 0;
    background: transparent;
    border: 0;
    text-align: center;
}

.site-footer p {
    margin: 0 auto;
    font-size: 0.78rem;
    line-height: 1.45;
    color: var(--text-muted);
    max-width: 980px;
}

.site-footer .footer-copyright {
    margin-top: 0.55rem;
    font-size: 0.72rem;
    letter-spacing: 0.02em;
}

@keyframes fade-up {
    from {
        opacity: 0;
        transform: translateY(14px);
    }
    to {
        opacity: 1;
        transform: translateY(0);
    }
}