/* ═══════════════════════════════════════════════════
   Portfolio — Unified Research Theme
   Light / Dark mode via [data-theme] attribute
   ═══════════════════════════════════════════════════ */

/* ── Reset ── */
*, *::before, *::after { box-sizing: border-box; margin: 0; padding: 0; }

/* ── Theme Variables — Light (default) ── */
:root {
    --navy:         #0d1b3e;
    --navy-mid:     #1a2f5e;
    --charcoal:     #1f2937;
    --body-text:    #374151;
    --muted:        #6b7280;
    --border:       #e5e7eb;
    --border-mid:   #d1d5db;
    --bg-page:      #f5f7fa;
    --bg-card:      #ffffff;
    --accent:       #1e40af;
    --accent-hover: #1e3a8a;
    --code-bg:      #f1f5f9;
    --code-border:  #e2e8f0;
}

/* ── Dark Mode Overrides ── */
[data-theme="dark"] {
    --charcoal:     #f1f5f9;
    --body-text:    #cbd5e1;
    --muted:        #94a3b8;
    --border:       #334155;
    --border-mid:   #475569;
    --bg-page:      #0f172a;
    --bg-card:      #1e293b;
    --accent:       #60a5fa;
    --accent-hover: #93c5fd;
    --code-bg:      #0d1b3e;
    --code-border:  #1e3a8a;
}

/* ── Base ── */
html { scroll-behavior: smooth; font-size: 17px; }

body {
    font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
    line-height: 1.7;
    color: var(--body-text);
    background-color: var(--bg-page);
    overflow-x: hidden;
    -webkit-font-smoothing: antialiased;
}

.container {
    max-width: 1200px;
    margin: 0 auto;
    padding: 0 2rem;
}

a { color: var(--accent); text-decoration: none; }
a:hover { text-decoration: underline; }

/* ── Theme Toggle Button ── */
.theme-toggle {
    background: rgba(255,255,255,0.08);
    border: 1px solid rgba(255,255,255,0.18);
    color: rgba(255,255,255,0.6);
    cursor: pointer;
    padding: 0.28rem 0.7rem;
    border-radius: 3px;
    font-size: 0.8rem;
    font-family: inherit;
    font-weight: 500;
    line-height: 1.6;
    transition: background 0.15s, color 0.15s;
    display: inline-flex;
    align-items: center;
    gap: 0.3rem;
}
.theme-toggle:hover { background: rgba(255,255,255,0.15); color: #fff; }
.toggle-dark { display: none; }
[data-theme="dark"] .toggle-light { display: none; }
[data-theme="dark"] .toggle-dark { display: inline; }

/* ── Navigation ── */
.navbar {
    position: fixed;
    top: 0;
    width: 100%;
    background: var(--navy);
    z-index: 1000;
    border-bottom: 1px solid rgba(255,255,255,0.07);
    transition: background 0.2s, box-shadow 0.2s;
}
.navbar.scrolled {
    background: var(--navy-mid);
    box-shadow: 0 2px 20px rgba(0,0,0,0.35);
}
[data-theme="dark"] .navbar.scrolled {
    background: #020b1a;
    box-shadow: 0 2px 24px rgba(0,0,0,0.6);
}

.navbar .container {
    display: flex;
    justify-content: space-between;
    align-items: center;
    padding: 1rem 2rem;
}

.logo {
    font-size: 1.25rem;
    font-weight: 700;
    color: #ffffff;
    text-decoration: none;
    letter-spacing: -0.01em;
}

.nav-links {
    display: flex;
    list-style: none;
    gap: 2rem;
    align-items: center;
}

.nav-links a {
    color: rgba(255,255,255,0.6);
    text-decoration: none;
    font-size: 0.85rem;
    font-weight: 500;
    transition: color 0.15s;
    position: relative;
}

.nav-links a:hover { color: #ffffff; text-decoration: none; }

.nav-links a::after {
    content: '';
    position: absolute;
    bottom: -4px;
    left: 0;
    width: 0;
    height: 1px;
    background: var(--accent);
    transition: width 0.2s;
}

.nav-links a:hover::after { width: 100%; }

.mobile-menu-toggle {
    display: none;
    flex-direction: column;
    gap: 4px;
    background: none;
    border: none;
    cursor: pointer;
}

.mobile-menu-toggle span {
    width: 22px;
    height: 2px;
    background: rgba(255,255,255,0.7);
    display: block;
    transition: all 0.25s;
}

/* ── Hero ── */
.hero {
    min-height: 100vh;
    display: flex;
    align-items: center;
    justify-content: center;
    padding: 7rem 2rem 5rem;
    background: var(--navy-mid);
    position: relative;
    overflow: hidden;
    transition: background 0.3s;
}
[data-theme="dark"] .hero {
    background: var(--navy);
}

.hero::after {
    content: '';
    position: absolute;
    bottom: 0;
    left: 0;
    right: 0;
    height: 3px;
    background: var(--accent);
}

.hero::before {
    content: '';
    position: absolute;
    top: -80px;
    right: -80px;
    width: 350px;
    height: 350px;
    border-radius: 50%;
    background: radial-gradient(circle, rgba(30,64,175,0.12) 0%, transparent 70%);
    pointer-events: none;
}

.hero-container {
    position: relative;
    z-index: 1;
    width: 100%;
    max-width: 700px;
    margin: 0 auto;
}

.hero-name {
    font-size: 4.2rem;
    font-weight: 700;
    line-height: 1.05;
    color: #ffffff;
    margin: 0 0 0.6rem;
    letter-spacing: -0.02em;
    animation: fadeInUp 0.6s ease both;
}

.hero-title {
    font-size: 1.25rem;
    font-weight: 400;
    color: rgba(255,255,255,0.55);
    margin: 0 0 1.75rem;
    animation: fadeInUp 0.6s ease 0.1s both;
}

.hero-bullets {
    list-style: none;
    padding: 0;
    margin: 0;
    display: flex;
    flex-direction: column;
    gap: 0.65rem;
    animation: fadeInUp 0.6s ease 0.2s both;
}

.hero-bullets li {
    font-size: 0.97rem;
    line-height: 1.75;
    color: rgba(255,255,255,0.52);
    padding-left: 1.1rem;
    position: relative;
}

.hero-bullets li::before {
    content: '—';
    position: absolute;
    left: 0;
    color: rgba(255,255,255,0.25);
}

.hero-bullets strong {
    color: rgba(255,255,255,0.82);
    font-weight: 600;
}

.hero-buttons {
    display: flex;
    gap: 0.75rem;
    flex-wrap: wrap;
    margin-top: 2rem;
    animation: fadeInUp 0.6s ease 0.3s both;
}

/* ── Buttons ── */
.btn {
    display: inline-block;
    padding: 0.65rem 1.5rem;
    border-radius: 3px;
    text-decoration: none;
    font-size: 0.86rem;
    font-weight: 600;
    font-family: inherit;
    transition: background 0.15s, color 0.15s, border-color 0.15s, transform 0.15s;
    border: 1px solid;
    cursor: pointer;
}

.btn-primary {
    background: var(--accent);
    color: #ffffff;
    border-color: var(--accent);
}
.btn-primary:hover {
    background: var(--accent-hover);
    border-color: var(--accent-hover);
    transform: translateY(-1px);
    text-decoration: none;
}

/* Hero variant — secondary on navy bg */
.hero .btn-secondary {
    background: transparent;
    color: rgba(255,255,255,0.72);
    border-color: rgba(255,255,255,0.25);
}
.hero .btn-secondary:hover {
    color: #fff;
    border-color: rgba(255,255,255,0.6);
    transform: translateY(-1px);
    text-decoration: none;
}

/* ── Section base ── */
section { padding: 5rem 0; }

.section-title {
    font-size: 1.9rem;
    font-weight: 700;
    color: var(--charcoal);
    text-align: center;
    margin-bottom: 0;
    letter-spacing: -0.01em;
    line-height: 1.2;
}

.section-title::after {
    content: '';
    display: block;
    width: 40px;
    height: 2px;
    background: var(--accent);
    margin: 0.7rem auto 2.5rem;
}

/* ── About ── */
.about {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.about-content { max-width: 800px; margin: 0 auto; }

.about-text p {
    font-size: 0.97rem;
    margin-bottom: 1.1rem;
    line-height: 1.85;
    color: var(--body-text);
}

.contact-info {
    display: flex;
    gap: 1.8rem;
    margin-top: 1.8rem;
    flex-wrap: wrap;
}

.contact-item {
    display: flex;
    align-items: center;
    gap: 0.45rem;
    font-size: 0.88rem;
    color: var(--muted);
}

.contact-item .icon { font-size: 1.1rem; }

.contact-item a { color: var(--accent); text-decoration: none; transition: color 0.15s; }
.contact-item a:hover { color: var(--accent-hover); }

/* ── Experience / Timeline ── */
.experience {
    background: var(--bg-page);
    border-bottom: 1px solid var(--border);
}

.timeline {
    position: relative;
    padding-left: 2rem;
    max-width: 860px;
    margin: 0 auto;
}

.timeline::before {
    content: '';
    position: absolute;
    left: 0;
    top: 0;
    bottom: 0;
    width: 1px;
    background: var(--border-mid);
}

.timeline-item { position: relative; padding-bottom: 2.2rem; }

.timeline-marker {
    position: absolute;
    left: -2.35rem;
    top: 0.35rem;
    width: 10px;
    height: 10px;
    border-radius: 50%;
    background: var(--accent);
    box-shadow: 0 0 0 3px var(--bg-page), 0 0 0 5px var(--border-mid);
}

.timeline-content {
    background: var(--bg-card);
    padding: 1.6rem;
    border: 1px solid var(--border);
    transition: border-color 0.2s;
}
.timeline-content:hover { border-color: var(--border-mid); }

.timeline-header {
    display: flex;
    justify-content: space-between;
    align-items: baseline;
    margin-bottom: 0.35rem;
    flex-wrap: wrap;
    gap: 0.5rem;
}

.timeline-header h3 {
    font-size: 1.08rem;
    color: var(--charcoal);
    font-weight: 700;
}

.company { font-weight: 600; color: var(--accent); font-size: 0.87rem; }

.timeline-meta {
    display: flex;
    gap: 1.2rem;
    margin-bottom: 1rem;
    flex-wrap: wrap;
}

.date, .location { color: var(--muted); font-size: 0.82rem; }

.timeline-achievements { list-style: none; padding-left: 0; }

.timeline-achievements li {
    position: relative;
    padding-left: 1.2rem;
    margin-bottom: 0.7rem;
    color: var(--body-text);
    line-height: 1.7;
    font-size: 0.9rem;
}

.timeline-achievements li::before {
    content: '▹';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-size: 0.9rem;
}

.timeline-achievements strong { color: var(--charcoal); font-weight: 600; }

/* ── Education ── */
.education {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.education-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(270px, 1fr));
    gap: 1.4rem;
}

.education-card {
    background: var(--bg-page);
    padding: 1.6rem;
    border: 1px solid var(--border);
    text-align: center;
    transition: border-color 0.2s, transform 0.2s;
}
.education-card:hover { border-color: var(--accent); transform: translateY(-3px); }

.education-icon { font-size: 2rem; margin-bottom: 0.9rem; }

.education-card h3 {
    font-size: 0.97rem;
    color: var(--charcoal);
    margin-bottom: 0.35rem;
    font-weight: 700;
}

.institution { color: var(--accent); font-weight: 600; margin-bottom: 0.25rem; font-size: 0.87rem; }
.duration { color: var(--muted); font-size: 0.82rem; margin-bottom: 0.7rem; }

.education-details { list-style: none; padding-left: 0; }
.education-details li { color: var(--body-text); font-size: 0.82rem; margin-top: 0.25rem; }

/* ── Skills ── */
.skills {
    background: var(--bg-page);
    border-bottom: 1px solid var(--border);
}

.skills-grid { display: grid; gap: 1.4rem; }

.skill-category {
    background: var(--bg-card);
    padding: 1.6rem;
    border: 1px solid var(--border);
}

.skill-category h3 {
    color: var(--charcoal);
    font-size: 0.92rem;
    font-weight: 700;
    margin-bottom: 0.9rem;
    text-transform: uppercase;
    letter-spacing: 0.05em;
}

.skill-tags { display: flex; flex-wrap: wrap; gap: 0.5rem; }

.tag {
    background: var(--bg-page);
    color: var(--body-text);
    padding: 0.3rem 0.75rem;
    font-size: 0.8rem;
    border: 1px solid var(--border);
    transition: all 0.15s;
    border-radius: 2px;
}
.tag:hover { background: var(--accent); color: #fff; border-color: var(--accent); }

/* ── Blog ── */
.blog {
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.blog-grid {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(290px, 1fr));
    gap: 1.4rem;
    margin-bottom: 2.5rem;
}

.blog-card {
    background: var(--bg-page);
    padding: 1.6rem;
    border: 1px solid var(--border);
    transition: border-color 0.2s, transform 0.2s;
    display: flex;
    flex-direction: column;
}
.blog-card:hover { border-color: var(--accent); transform: translateY(-3px); }

.blog-meta {
    display: flex;
    gap: 0.9rem;
    margin-bottom: 0.75rem;
    font-size: 0.77rem;
    color: var(--muted);
}

.blog-title {
    font-size: 1.1rem;
    color: var(--charcoal);
    margin-bottom: 0.7rem;
    line-height: 1.35;
    font-weight: 700;
}

.blog-excerpt {
    color: var(--body-text);
    line-height: 1.7;
    margin-bottom: 1.1rem;
    flex-grow: 1;
    font-size: 0.9rem;
}

.blog-read-more {
    color: var(--accent);
    text-decoration: none;
    font-weight: 600;
    font-size: 0.85rem;
    display: inline-flex;
    align-items: center;
    transition: color 0.15s;
}
.blog-read-more:hover { color: var(--accent-hover); }

.blog-view-all { text-align: center; }

.no-blogs {
    text-align: center;
    padding: 3rem;
    color: var(--muted);
    font-size: 1rem;
}

.alert {
    padding: 0.9rem 1.2rem;
    margin-bottom: 1.4rem;
    text-align: center;
    font-size: 0.88rem;
    border: 1px solid;
}

.alert-error { background: #fef2f2; border-color: #fecaca; color: #991b1b; }
[data-theme="dark"] .alert-error { background: rgba(220,38,38,0.08); border-color: rgba(220,38,38,0.25); color: #fca5a5; }
.alert-success { background: #f0fdf4; border-color: #bbf7d0; color: #166534; }
[data-theme="dark"] .alert-success { background: rgba(22,163,74,0.08); border-color: rgba(22,163,74,0.25); color: #86efac; }

/* ── Contact ── */
.contact {
    background: var(--bg-page);
    border-bottom: 1px solid var(--border);
}

.contact-content { max-width: 800px; margin: 0 auto; text-align: center; }

.contact-description {
    font-size: 1rem;
    margin-bottom: 2.5rem;
    color: var(--body-text);
    line-height: 1.8;
}

.contact-methods {
    display: grid;
    grid-template-columns: repeat(auto-fit, minmax(220px, 1fr));
    gap: 1.2rem;
    text-align: left;
}

.contact-method {
    background: var(--bg-card);
    padding: 1.4rem;
    border: 1px solid var(--border);
    text-decoration: none;
    display: flex;
    align-items: center;
    gap: 0.9rem;
    transition: border-color 0.15s;
    color: var(--body-text);
}
.contact-method:hover { border-color: var(--accent); text-decoration: none; }

.contact-icon { font-size: 1.5rem; line-height: 1; }

.contact-method h4 {
    color: var(--charcoal);
    margin-bottom: 0.15rem;
    font-weight: 600;
    font-size: 0.87rem;
}
.contact-method p { color: var(--muted); margin: 0; font-size: 0.82rem; }

/* ── Footer ── */
.footer {
    background: var(--navy);
    padding: 2rem 0;
    text-align: center;
    border-top: 1px solid rgba(255,255,255,0.07);
}

.footer p { color: rgba(255,255,255,0.35); font-size: 0.8rem; }

/* ── Animations ── */
@keyframes fadeInUp {
    from { opacity: 0; transform: translateY(18px); }
    to   { opacity: 1; transform: translateY(0); }
}

/* ── Publications Section ── */
.publications {
    padding: 5rem 0;
    background: var(--bg-page);
    border-bottom: 1px solid var(--border);
}

.section-subtitle {
    text-align: center;
    color: var(--muted);
    font-size: 0.85rem;
    margin-top: -2rem;
    margin-bottom: 3rem;
    letter-spacing: 0.02em;
}

.publications-list { display: flex; flex-direction: column; gap: 1.4rem; }

.publication-card {
    display: flex;
    gap: 1.4rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    border-left: 3px solid var(--accent);
    padding: 1.8rem 1.8rem 1.8rem 1.6rem;
    transition: border-color 0.2s;
}
.publication-card:hover { border-color: var(--border-mid); border-left-color: var(--accent-hover); }

.publication-number {
    font-size: 1.2rem;
    font-weight: 700;
    color: var(--muted);
    min-width: 2.2rem;
    padding-top: 0.1rem;
}

.publication-body { flex: 1; }

.publication-title {
    font-size: 1.02rem;
    font-weight: 700;
    color: var(--charcoal);
    margin-bottom: 0.35rem;
    line-height: 1.4;
}

.publication-meta {
    font-size: 0.8rem;
    color: var(--muted);
    margin-bottom: 0.8rem;
    font-weight: 500;
    display: flex;
    align-items: center;
    gap: 0.5rem;
    flex-wrap: wrap;
}

.pub-venue-badge {
    font-size: 0.7rem;
    font-weight: 700;
    letter-spacing: 0.04em;
    color: var(--accent);
    background: #eff6ff;
    border: 1px solid #bfdbfe;
    padding: 0.15rem 0.5rem;
    border-radius: 2px;
}
[data-theme="dark"] .pub-venue-badge {
    background: rgba(96,165,250,0.1);
    border-color: rgba(96,165,250,0.25);
    color: #93c5fd;
}

.publication-highlights { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 0.4rem; }

.publication-highlights li {
    color: var(--body-text);
    font-size: 0.88rem;
    padding-left: 1.1rem;
    position: relative;
    line-height: 1.65;
}

.publication-highlights li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-size: 0.82rem;
}

/* Publication links row */
.publication-links { display: flex; gap: 0.55rem; margin-top: 1rem; flex-wrap: wrap; }

.pub-link {
    font-size: 0.74rem;
    font-weight: 600;
    letter-spacing: 0.03em;
    padding: 0.22rem 0.6rem;
    border-radius: 2px;
    text-decoration: none;
    transition: all 0.15s;
    border: 1px solid;
}

.pub-link-soon {
    color: var(--muted);
    border-color: var(--border);
    background: transparent;
    cursor: default;
    opacity: 0.65;
}

/* ── Research Section ── */
.research {
    padding: 5rem 0;
    background: var(--bg-card);
    border-bottom: 1px solid var(--border);
}

.research-origin {
    text-align: center;
    font-size: 0.77rem;
    font-weight: 600;
    color: var(--muted);
    letter-spacing: 0.03em;
    margin-top: -2rem;
    margin-bottom: 2rem;
}

.research-card {
    background: var(--bg-page);
    border: 1px solid var(--border);
    border-left: 4px solid var(--accent);
    padding: 2.2rem;
    transition: border-color 0.2s;
}
.research-card:hover { border-color: var(--border-mid); border-left-color: var(--accent-hover); }

.research-header {
    display: flex;
    justify-content: space-between;
    align-items: flex-start;
    margin-bottom: 1.2rem;
    flex-wrap: wrap;
    gap: 0.75rem;
}

.research-name { font-size: 1.25rem; font-weight: 700; color: var(--charcoal); }

.research-name-link {
    color: inherit;
    text-decoration: none;
    border-bottom: 1px solid transparent;
    transition: border-color 0.2s;
}
.research-name-link:hover { border-color: var(--accent); }

.research-tagline { font-size: 0.87rem; color: var(--muted); margin-top: 0.2rem; }

.research-date {
    font-size: 0.78rem;
    color: var(--muted);
    background: var(--bg-card);
    padding: 0.22rem 0.7rem;
    border: 1px solid var(--border);
    white-space: nowrap;
    border-radius: 2px;
}

.research-highlights { list-style: none; padding: 0; display: flex; flex-direction: column; gap: 0.5rem; }

.research-highlights li {
    color: var(--body-text);
    font-size: 0.9rem;
    padding-left: 1.1rem;
    position: relative;
    line-height: 1.65;
}

.research-highlights li::before {
    content: '▸';
    position: absolute;
    left: 0;
    color: var(--accent);
    font-size: 0.82rem;
}

.research-actions { display: flex; gap: 0.9rem; margin-top: 1.8rem; flex-wrap: wrap; }

.research-btn {
    flex: 1;
    min-width: 170px;
    padding: 0.78rem 1.3rem;
    text-align: center;
    font-size: 0.85rem;
    font-weight: 600;
    text-decoration: none;
    border: 1px solid;
    border-radius: 2px;
    transition: all 0.15s;
}

.research-btn-primary { background: var(--accent); color: #fff; border-color: var(--accent); }
.research-btn-primary:hover { background: var(--accent-hover); border-color: var(--accent-hover); text-decoration: none; }

.research-btn-secondary { background: transparent; color: var(--charcoal); border-color: var(--border-mid); }
.research-btn-secondary:hover { border-color: var(--accent); color: var(--accent); text-decoration: none; }

/* ── Certifications ── */
.certifications {
    padding: 4rem 0;
    background: var(--bg-page);
    border-bottom: 1px solid var(--border);
}

.certs-grid { display: grid; grid-template-columns: repeat(auto-fit, minmax(250px, 1fr)); gap: 1.3rem; }

.cert-card {
    display: flex;
    align-items: flex-start;
    gap: 0.9rem;
    background: var(--bg-card);
    border: 1px solid var(--border);
    padding: 1.4rem;
    transition: border-color 0.2s, transform 0.15s;
}
.cert-card:hover { border-color: var(--accent); transform: translateY(-2px); }

.cert-icon { font-size: 1.3rem; line-height: 1; }
.cert-name { font-size: 0.95rem; font-weight: 700; color: var(--charcoal); margin-bottom: 0.15rem; }
.cert-issuer { font-size: 0.82rem; color: var(--muted); margin-bottom: 0.35rem; }

.cert-status {
    font-size: 0.73rem;
    font-weight: 600;
    padding: 0.12rem 0.5rem;
    border-radius: 2px;
    display: inline-block;
    border: 1px solid;
}

.cert-scheduled { background: #eff6ff; color: var(--accent); border-color: #bfdbfe; }
.cert-planned { background: var(--bg-page); color: var(--muted); border-color: var(--border); }
[data-theme="dark"] .cert-scheduled { background: rgba(96,165,250,0.1); border-color: rgba(96,165,250,0.25); color: #93c5fd; }

/* ── Blog content ── */
.blog-content img { max-width: 100%; height: auto; margin: 1.8rem 0; border: 1px solid var(--border); }

.blog-content pre {
    background: var(--code-bg);
    border: 1px solid var(--code-border);
    border-left: 3px solid var(--accent);
    padding: 1.3rem;
    overflow-x: auto;
    margin: 1.4rem 0;
}

.blog-content code {
    font-family: 'Source Code Pro', 'Courier New', monospace;
    font-size: 0.83em;
    background: var(--code-bg);
    padding: 0.1em 0.3em;
    border: 1px solid var(--code-border);
}

.blog-content pre code { background: none; border: none; padding: 0; color: var(--body-text); }

.blog-content h1, .blog-content h2, .blog-content h3 {
    color: var(--charcoal);
    margin-top: 1.8rem;
    margin-bottom: 0.75rem;
}

.blog-content ul, .blog-content ol { color: var(--body-text); margin-left: 2rem; margin-bottom: 1.2rem; }
.blog-content a { color: var(--accent); text-decoration: none; }
.blog-content a:hover { text-decoration: underline; }

/* ── Responsive ── */
@media (max-width: 768px) {
    .nav-links {
        position: fixed;
        top: 58px;
        left: -100%;
        flex-direction: column;
        background: var(--navy);
        width: 100%;
        padding: 1.5rem 2rem;
        gap: 0.75rem;
        transition: left 0.3s;
        border-bottom: 1px solid rgba(255,255,255,0.08);
        z-index: 999;
    }

    .nav-links.active { left: 0; }

    .mobile-menu-toggle { display: flex; }

    .mobile-menu-toggle.active span:nth-child(1) { transform: rotate(45deg) translate(4px, 4px); }
    .mobile-menu-toggle.active span:nth-child(2) { opacity: 0; }
    .mobile-menu-toggle.active span:nth-child(3) { transform: rotate(-45deg) translate(6px, -5px); }

    .hero { padding: 6rem 1.5rem 4rem; min-height: auto; align-items: flex-start; }
    .hero-name { font-size: 3rem; }
    .hero-title { font-size: 1.05rem; }

    .hero-buttons { flex-direction: row; flex-wrap: wrap; }

    .section-title { font-size: 1.65rem; }

    .contact-info { flex-direction: column; gap: 0.75rem; }

    .timeline { padding-left: 1.5rem; }
    .timeline-marker { left: -1.9rem; }

    .publication-card { flex-direction: column; gap: 0.6rem; }
    .publication-number { font-size: 1rem; }

    .research-header { flex-direction: column; }
    .research-origin { margin-top: -1.5rem; }
    .research-actions { flex-direction: column; }
}

@media (max-width: 480px) {
    .container { padding: 0 1.25rem; }

    .hero { padding: 5.5rem 1.25rem 3.5rem; }
    .hero-name { font-size: 2.4rem; }

    .hero-buttons { flex-direction: column; gap: 0.6rem; }
    .hero-buttons .btn { width: 100%; text-align: center; }
}