/* ==========================================
   LAYOUT — navbar, hero, section headers, footer, responsive
   ========================================== */

/* NAVBAR */
.navbar {
    position: fixed;
    top: 1.25rem;
    left: 50%;
    transform: translateX(-50%);
    width: min(96%, var(--max-width));
    background: rgba(5, 5, 5, 0.85);
    border: 1px solid var(--border-soft);
    border-radius: 999px;
    box-shadow: var(--shadow-soft);
    z-index: 1000;
    transition: all 0.3s ease;
    backdrop-filter: blur(16px);
}

/* Applied by ui.js once the page is scrolled past the hero */
.navbar.is-scrolled {
    background: rgba(4, 4, 4, 0.95);
    box-shadow: 0 20px 60px rgba(0, 0, 0, 0.55);
}

.navbar .container {
    display: flex;
    align-items: center;
    justify-content: space-between;
    padding: 0.8rem 1.5rem;
}

.nav-brand {
    display: flex;
    align-items: center;
    gap: 0.5rem;
}

.nav-home {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.8rem;
    letter-spacing: 0.12em;
    text-transform: uppercase;
    transition: color 0.3s ease;
}

.nav-home:hover {
    color: var(--accent-primary);
}

.nav-menu {
    display: flex;
    list-style: none;
    gap: 1.5rem;
}

.nav-link {
    color: var(--text-muted);
    text-decoration: none;
    font-size: 0.9rem;
    letter-spacing: 0.04em;
    position: relative;
    padding-bottom: 0.2rem;
    transition: color 0.3s ease;
}

.nav-link::after {
    content: '';
    position: absolute;
    left: 0;
    bottom: 0;
    width: 100%;
    height: 1px;
    background: linear-gradient(90deg, transparent, var(--accent-primary), transparent);
    transform: scaleX(0);
    transform-origin: center;
    transition: transform 0.3s ease;
}

.nav-link:hover,
.nav-link.active {
    color: var(--text-strong);
}

.nav-link:hover::after,
.nav-link.active::after {
    transform: scaleX(1);
}

.hamburger {
    display: none;
    flex-direction: column;
    gap: 4px;
    cursor: pointer;
}

.hamburger span {
    width: 24px;
    height: 2px;
    background: var(--text-strong);
    transition: all 0.3s ease;
}

/* HERO */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    position: relative;
    padding: 9rem 0 6rem;
}

.hero-background {
    position: absolute;
    inset: 0;
    background: #000;
    z-index: 0;
}

.hero-content {
    display: grid;
    grid-template-columns: 1.2fr 0.9fr;
    align-items: start;
    gap: 4rem;
    position: relative;
    z-index: 1;
}

.hero-text {
    display: flex;
    flex-direction: column;
    gap: 1.2rem;
}

.hero-badge {
    display: inline-flex;
    align-items: center;
    gap: 0.45rem;
    background: rgba(132, 255, 162, 0.08);
    border: 1px solid rgba(132, 255, 162, 0.2);
    color: var(--success);
    padding: 0.35rem 0.9rem;
    border-radius: 999px;
    font-size: 0.85rem;
    letter-spacing: 0.06em;
    text-transform: uppercase;
    align-self: flex-start;
}

.badge-dot {
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: var(--success);
    display: inline-block;
    animation: pulse 2.4s infinite;
}

.hero-title {
    font-size: clamp(2.7rem, 5vw, 4.8rem);
    letter-spacing: -0.02em;
    display: flex;
    flex-direction: column;
    gap: 0.5rem;
}

.hero-title .greeting {
    font-size: 1.1rem;
    color: var(--text-muted);
}

.hero-title .name {
    font-weight: 700;
}

.gradient-text {
    color: var(--text-strong);
    background: linear-gradient(120deg, var(--text-strong), var(--accent-primary));
    -webkit-background-clip: text;
    -webkit-text-fill-color: transparent;
}

.hero-meta {
    display: flex;
    flex-direction: column;
    gap: 0.2rem;
    color: var(--text-muted);
    font-size: 0.95rem;
}

.hero-tags {
    display: flex;
    flex-wrap: wrap;
    gap: 0.6rem;
}

.hero-pill {
    padding: 0.35rem 0.95rem;
    border-radius: 999px;
    border: 1px solid var(--border-soft);
    background: var(--panel);
    font-size: 0.85rem;
    color: var(--text-strong);
    letter-spacing: 0.05em;
    text-transform: uppercase;
}

.hero-description {
    max-width: 620px;
    font-size: 1rem;
}

.hero-note {
    font-size: 0.95rem;
    color: var(--text-muted);
    border-left: 2px solid var(--border-soft);
    padding-left: 1rem;
}

.hero-buttons {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
}

.hero-stats {
    display: flex;
    gap: 2rem;
    padding-top: 0.5rem;
    border-top: 1px solid var(--border-soft);
}

.stat-item {
    display: flex;
    flex-direction: column;
}

.stat-number {
    font-size: 2.25rem;
    color: var(--text-strong);
    font-weight: 600;
}

.stat-label {
    font-size: 0.85rem;
    color: var(--text-muted);
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

.hero-image {
    position: relative;
    isolation: isolate;
}

.image-wrapper,
.image-frame {
    position: relative;
    background: transparent;
}

.image-frame {
    overflow: visible;
}

.image-frame img {
    width: clamp(320px, 100%, 520px);
    height: auto;
    display: block;
    position: relative;
    z-index: 1;
    filter: contrast(1.04) saturate(1.05);
    background: #010101;
    box-shadow: 0 40px 120px rgba(0, 0, 0, 0.6);
}

/* SECTION HEADER */
.section-header {
    text-align: left;
    margin-bottom: 3rem;
}

.section-label {
    display: inline-flex;
    font-size: 0.8rem;
    text-transform: uppercase;
    letter-spacing: 0.35em;
    color: var(--text-muted);
    border-bottom: 1px solid var(--border-soft);
    padding-bottom: 0.6rem;
}

.section-title {
    font-size: clamp(2rem, 4vw, 3rem);
    margin-top: 1rem;
}

.section-description {
    color: var(--text-muted);
    max-width: 600px;
    margin-top: 0.5rem;
}

/* FOOTER */
.footer {
    padding: 2rem 0 4rem;
    border-top: 1px solid var(--border-soft);
    text-align: center;
    color: var(--text-muted);
}

.footer-content {
    display: flex;
    align-items: center;
    justify-content: space-between;
    flex-wrap: wrap;
    gap: 1.5rem;
    text-align: left;
}

.footer-brand h3 {
    letter-spacing: 0.12em;
    text-transform: uppercase;
}

.footer-links {
    display: flex;
    flex-wrap: wrap;
    gap: 1rem;
    justify-content: center;
}

.footer-links a {
    color: var(--text-body);
    text-decoration: none;
    letter-spacing: 0.15em;
    font-size: 0.8rem;
    text-transform: uppercase;
    transition: color 0.3s ease;
}

.footer-links a:hover {
    color: var(--accent-primary);
}

.footer-bottom {
    margin-top: 1.5rem;
    display: flex;
    flex-direction: column;
    gap: 0.3rem;
    letter-spacing: 0.08em;
    text-transform: uppercase;
}

/* RESPONSIVE */
@media (max-width: 1100px) {
    .hero-content {
        grid-template-columns: 1fr;
    }

    .hero-image {
        order: -1;
    }
}

@media (max-width: 900px) {
    .navbar {
        border-radius: 24px;
    }

    .nav-menu {
        position: fixed;
        top: 80px;
        right: 1.5rem;
        flex-direction: column;
        background: rgba(4, 4, 4, 0.98);
        border: 1px solid var(--border-soft);
        border-radius: 20px;
        padding: 1.5rem;
        width: 240px;
        transform: translateY(-20px);
        opacity: 0;
        pointer-events: none;
        transition: all 0.3s ease;
    }

    .nav-menu.active {
        opacity: 1;
        transform: translateY(0);
        pointer-events: auto;
    }

    .hamburger {
        display: flex;
    }

    .about-content,
    .timeline-item {
        grid-template-columns: 1fr;
    }

    .hero-stats {
        flex-wrap: wrap;
    }
}

@media (max-width: 640px) {
    .hero-title {
        font-size: 2.3rem;
    }

    .projects-showcase {
        padding: 1.5rem;
    }

    .publication-card {
        grid-template-columns: 1fr;
    }

    .pub-year {
        border-right: none;
        border-bottom: 1px solid var(--border-soft);
    }

    .container {
        padding: 0 1rem;
    }

    .hero-buttons {
        flex-direction: column;
        align-items: stretch;
    }
}