#navigationbar {
    background: var(--color-nav-bg);
    backdrop-filter: var(--blur-nav);
    -webkit-backdrop-filter: var(--blur-nav);
    border-bottom: 1px solid var(--color-glass-border);
    margin-bottom: var(--space-lg);
    position: sticky;
    top: 0;
    z-index: var(--z-nav);
}

.nav-links {
    display: flex;
    flex-wrap: wrap;
    justify-content: center;
    padding: 0 1em;
    gap: 0.25em;
}

.nav-links a {
    border-radius: var(--radius-sm);
    color: var(--color-text-muted);
    display: inline-block;
    font-family: var(--font-condensed);
    font-size: var(--font-size-xl);
    letter-spacing: 0.03em;
    padding: 0.65em 0.75em;
    position: relative;
    transition: var(--transition-glow), background 0.2s ease;
}

.nav-links a svg {
    height: 1em;
    width: 1em;
    margin-right: 0.4em;
    vertical-align: -0.1em;
}

.nav-links a::after {
    background: var(--color-accent);
    border-radius: var(--radius-indicator);
    bottom: 0.4em;
    content: '';
    height: 2px;
    left: 0.75em;
    position: absolute;
    right: 0.75em;
    transform: scaleX(0);
    transition: transform 0.2s ease;
}

.nav-links a:hover {
    background: var(--color-accent-subtle);
    color: var(--color-accent);
    opacity: 1;
    animation: icon-glitch 0.25s steps(1) forwards;
}

.glitch-disabled .nav-links a:hover {
    animation: none;
}

.nav-links a:hover::after {
    transform: scaleX(0.5);
}

/* Active page */
#home         .nav-links a.home,
#portfolio    .nav-links a.portfolio,
#blog         .nav-links a.blog,
#publications .nav-links a.publications,
.nav-links a[aria-current="page"] {
    background: var(--color-accent-subtle);
    color: var(--color-accent);
}

#home         .nav-links a.home::after,
#portfolio    .nav-links a.portfolio::after,
#blog         .nav-links a.blog::after,
#publications .nav-links a.publications::after,
.nav-links a[aria-current="page"]::after {
    transform: scaleX(1);
}

/* ── Hamburger toggle ────────────────────────────────────── */
.nav-toggle {
    display: none;
    background: none;
    border: none;
    cursor: pointer;
    padding: 0.75em 1em;
    position: absolute;
    right: 0;
    top: 0;
}

.nav-toggle span {
    background-color: var(--color-text-muted);
    border-radius: var(--radius-indicator);
    display: block;
    height: 2px;
    margin: 5px 0;
    transition: transform 0.25s ease, opacity 0.25s ease, background-color 0.2s;
    width: 22px;
}

.nav-toggle:hover span {
    background-color: var(--color-accent);
}

.nav-toggle[aria-expanded="true"] span:nth-child(1) {
    transform: translateY(7px) rotate(45deg);
}
.nav-toggle[aria-expanded="true"] span:nth-child(2) {
    opacity: 0;
}
.nav-toggle[aria-expanded="true"] span:nth-child(3) {
    transform: translateY(-7px) rotate(-45deg);
}

/* ── Responsive ──────────────────────────────────────────── */
@media screen and (max-width: 46em) {
    #navigationbar {
        padding-bottom: 0;
        padding-top: 0.5em;
    }

    .nav-toggle {
        display: block;
    }

    .nav-links {
        flex-direction: column;
        align-items: stretch;
        padding-bottom: 0;
        gap: 0;
        max-height: 0;
        overflow: hidden;
        visibility: hidden;
        transition: max-height 0.3s ease, visibility 0.3s ease;
    }

    .nav-links.open {
        max-height: 20em;
        padding-bottom: 0.5em;
        visibility: visible;
    }

    /* No-JS fallback: expand nav when a nav link receives keyboard focus.
       Excludes the hamburger button itself so clicking Close does not
       immediately re-open the nav while the button retains focus. */
    #navigationbar:focus-within:not(:has(.nav-toggle:focus)) .nav-links {
        max-height: 20em;
        padding-bottom: 0.5em;
        visibility: visible;
    }

    .nav-links a {
        width: 100%;
        text-align: center;
        margin: 0;
        border-radius: 0;
        padding: 0.7em 1em;
    }

    .nav-links a::after {
        display: none;
    }

    #home         .nav-links a.home,
    #portfolio    .nav-links a.portfolio,
    #blog         .nav-links a.blog,
    #publications .nav-links a.publications,
    .nav-links a[aria-current="page"] {
        border-left: 3px solid var(--color-accent);
    }
}

@media (prefers-reduced-motion: reduce) {
    .nav-links {
        transition: none;
    }
    .nav-links a::after {
        transition: none;
    }
    .nav-links a:hover {
        animation: none;
    }
    .nav-toggle span {
        transition: none;
    }
}