/* ---------- Design tokens ---------- */
:root {
  --bg: #ffffff;
  --bg-elev: #ffffff;
  --bg-alt: #f6f8fa;
  --text: #1a1f2b;
  --muted: #5b6472;
  --line: #e3e7ec;
  --accent: #1f5fbf;
  --accent-strong: #174a99;
  --accent-soft: #eaf1fb;
  --accent-text: #174a99;
  --on-accent: #ffffff;
  --shadow: 0 1px 2px rgba(16, 24, 40, 0.05), 0 8px 24px -18px rgba(16, 24, 40, 0.18);
  --radius: 12px;
  --radius-sm: 8px;
  --max: 1120px;
  --font: "Inter", system-ui, -apple-system, "Segoe UI", Roboto, sans-serif;
  --font-display: "Source Serif 4", Georgia, "Times New Roman", serif;
}
[data-theme="dark"] {
  --bg: #0f141c;
  --bg-elev: #161c26;
  --bg-alt: #121821;
  --text: #e8ecf1;
  --muted: #9aa5b4;
  --line: #273140;
  --accent: #7fb0f5;
  --accent-strong: #a3c6f8;
  --accent-soft: #1a2b45;
  --accent-text: #9cc3f8;
  --on-accent: #0b1220;
  --shadow: 0 1px 2px rgba(0, 0, 0, 0.4), 0 12px 28px -18px rgba(0, 0, 0, 0.7);
}

/* ---------- Base ---------- */
*, *::before, *::after { box-sizing: border-box; }
html { scroll-behavior: smooth; -webkit-text-size-adjust: 100%; }
@media (prefers-reduced-motion: reduce) { html { scroll-behavior: auto; } }
body {
  margin: 0;
  font-family: var(--font);
  font-size: 17px;
  line-height: 1.65;
  color: var(--text);
  background: var(--bg);
  -webkit-font-smoothing: antialiased;
}
img { max-width: 100%; height: auto; display: block; }
a { color: var(--accent-text); text-decoration: none; }
a:hover { text-decoration: underline; text-underline-offset: 3px; }
h1, h2, h3, h4 { line-height: 1.2; margin: 0 0 0.5em; }
h1, h2 { font-family: var(--font-display); font-weight: 600; letter-spacing: -0.01em; }
h1 { font-size: clamp(2.5rem, 5vw, 3.6rem); line-height: 1.08; }
h2 { font-size: clamp(1.75rem, 3.2vw, 2.3rem); }
h3 { font-size: 1.15rem; font-weight: 700; }
h4 { font-size: 1.05rem; font-weight: 700; }
p { margin: 0 0 1em; }
ul, ol { margin: 0; padding: 0; list-style: none; }
.container { max-width: var(--max); margin: 0 auto; padding: 0 20px; }
.skip-link { position: absolute; left: -999px; top: 8px; background: var(--accent); color: var(--on-accent); padding: 8px 12px; border-radius: 6px; z-index: 100; }
.skip-link:focus { left: 8px; }
:focus-visible { outline: 3px solid var(--accent); outline-offset: 3px; border-radius: 4px; }

/* ---------- Buttons ---------- */
.btn {
  display: inline-flex; align-items: center; gap: 8px;
  padding: 11px 20px; border-radius: var(--radius-sm);
  font-weight: 600; font-size: 0.95rem; line-height: 1;
  border: 1px solid transparent; cursor: pointer;
  transition: background .15s ease, border-color .15s ease, color .15s ease;
  font-family: inherit;
}
.btn:hover { text-decoration: none; }
.btn-primary { background: var(--accent); color: var(--on-accent); border-color: var(--accent); }
.btn-primary:hover { background: var(--accent-strong); border-color: var(--accent-strong); }
.btn-outline { border-color: var(--line); color: var(--text); background: var(--bg-elev); }
.btn-outline:hover { border-color: var(--accent); color: var(--accent-text); }
.btn-ghost { color: var(--accent-text); background: transparent; }
.btn-ghost:hover { background: var(--accent-soft); }
.btn-sm { padding: 8px 14px; font-size: 0.85rem; }
.icon-btn {
  width: 40px; height: 40px; border-radius: var(--radius-sm); border: 1px solid var(--line);
  background: var(--bg-elev); color: var(--text); display: inline-grid; place-items: center; cursor: pointer;
}
.icon-btn:hover { border-color: var(--accent); }

/* ---------- Header ---------- */
.site-header {
  position: sticky; top: 0; z-index: 50;
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.header-inner { display: flex; align-items: center; justify-content: space-between; gap: 16px; height: 68px; }
.brand { display: inline-flex; align-items: center; gap: 10px; color: var(--text); font-weight: 700; }
.brand:hover { text-decoration: none; }
.brand-mark {
  width: 36px; height: 36px; border-radius: 8px; display: grid; place-items: center;
  background: var(--accent); color: var(--on-accent); font-size: 0.8rem; font-weight: 800; letter-spacing: 0.02em;
}
.site-nav { display: flex; align-items: center; gap: 2px; }
.site-nav a:not(.btn) { padding: 8px 11px; border-radius: 6px; color: var(--muted); font-weight: 500; font-size: 0.93rem; }
.site-nav a:not(.btn):hover, .site-nav a.active { color: var(--accent-text); background: var(--accent-soft); text-decoration: none; }
.nav-cv { margin-left: 8px; }
.header-actions { display: flex; align-items: center; gap: 8px; }
.nav-toggle { display: none; flex-direction: column; gap: 5px; }
.nav-toggle span { width: 18px; height: 2px; background: currentColor; border-radius: 2px; transition: transform .2s, opacity .2s; }
.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); }
.icon-sun { display: none; }
[data-theme="dark"] .icon-sun { display: block; }
[data-theme="dark"] .icon-moon { display: none; }

/* ---------- Hero ---------- */
.hero {
  padding: clamp(56px, 8vw, 96px) 0 clamp(48px, 6vw, 80px);
  background: var(--bg);
  border-bottom: 1px solid var(--line);
}
.hero-grid { display: grid; grid-template-columns: 1.15fr 0.85fr; gap: 56px; align-items: center; }
.eyebrow {
  display: inline-block; font-size: 0.78rem; font-weight: 700; letter-spacing: 0.08em; text-transform: uppercase;
  color: var(--accent-text); margin-bottom: 14px;
}
.tagline { font-size: clamp(1.2rem, 2.2vw, 1.45rem); font-weight: 500; color: var(--text); margin-bottom: 18px; line-height: 1.4; }
.accent { color: var(--accent-text); }
.lead { color: var(--muted); font-size: 1.05rem; max-width: 60ch; }
.hero-actions { display: flex; flex-wrap: wrap; gap: 12px; margin: 28px 0 30px; }
.hero-facts { display: flex; flex-wrap: wrap; gap: 10px 24px; color: var(--muted); font-size: 0.95rem; }
.hero-facts li { display: inline-flex; align-items: center; gap: 8px; }
.hero-facts svg { color: var(--accent-text); flex: none; }
.hero-photo { display: flex; justify-content: center; }
.photo-frame {
  position: relative; width: min(360px, 100%); border-radius: var(--radius); overflow: hidden;
  box-shadow: var(--shadow); border: 1px solid var(--line); background: var(--bg-elev);
}
.photo-frame img { aspect-ratio: 3 / 4; object-fit: cover; width: 100%; }

/* ---------- Sections ---------- */
.section { padding: clamp(60px, 7vw, 96px) 0; scroll-margin-top: 72px; }
.section-alt { background: var(--bg-alt); border-top: 1px solid var(--line); border-bottom: 1px solid var(--line); }
.section-head { max-width: 720px; margin-bottom: 36px; }
.section-head h2 { margin-bottom: 10px; }
.section-intro { color: var(--muted); font-size: 1.05rem; }
.group-title { margin: 36px 0 18px; font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); font-weight: 700; }
.cards-2 + .group-title { margin-top: 48px; }

/* ---------- About ---------- */
.about-grid { display: grid; grid-template-columns: 1.4fr 1fr; gap: 48px; align-items: start; }
.about-text p { color: var(--muted); }
.about-text p:first-child { font-size: 1.15rem; font-weight: 500; color: var(--text); }
.facts { display: grid; margin: 0; background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.facts > div { padding: 14px 20px; border-bottom: 1px solid var(--line); }
.facts > div:last-child { border-bottom: none; }
.facts dt { font-size: 0.74rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--accent-text); margin-bottom: 2px; }
.facts dd { margin: 0; color: var(--text); font-size: 0.95rem; }

/* ---------- Cards ---------- */
.cards-4 { display: grid; grid-template-columns: repeat(4, 1fr); gap: 18px; }
.cards-3 { display: grid; grid-template-columns: repeat(3, 1fr); gap: 20px; }
.cards-2 { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.card {
  background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius);
  padding: 24px; display: flex; flex-direction: column; gap: 12px;
  transition: border-color .2s ease, box-shadow .2s ease;
}
.card:hover { border-color: var(--accent); box-shadow: var(--shadow); }
.card p { color: var(--muted); margin: 0; font-size: 0.97rem; }
.card h3 { margin: 0; }
.card-icon { width: 42px; height: 42px; border-radius: 10px; display: grid; place-items: center; background: var(--accent-soft); color: var(--accent-text); }
.project header { display: flex; align-items: flex-start; justify-content: space-between; gap: 12px; }
.badge {
  flex: none; font-size: 0.68rem; font-weight: 700; letter-spacing: 0.06em; text-transform: uppercase;
  padding: 4px 9px; border-radius: 6px; background: var(--accent-soft); color: var(--accent-text);
}
.badge-muted { background: var(--bg-alt); color: var(--muted); border: 1px solid var(--line); }
.tags { display: flex; flex-wrap: wrap; gap: 8px; margin-top: auto; }
.tags li { font-size: 0.8rem; font-weight: 500; padding: 5px 10px; border-radius: 6px; background: var(--bg-alt); border: 1px solid var(--line); color: var(--muted); }
.tags-lg li { font-size: 0.9rem; padding: 7px 13px; background: var(--bg-elev); }
.card-link { font-weight: 600; font-size: 0.95rem; }
.card-link::after { content: " \2192"; }

/* ---------- Interests ---------- */
.interests { margin-top: 32px; }
.interests h3 { font-size: 0.85rem; text-transform: uppercase; letter-spacing: 0.08em; color: var(--muted); margin-bottom: 14px; }

/* ---------- Gallery ---------- */
.gallery { columns: 3; column-gap: 18px; }
.gallery figure { margin: 0 0 18px; break-inside: avoid; background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); overflow: hidden; }
.gallery img { width: 100%; height: auto; }
.gallery figcaption { padding: 12px 16px; font-size: 0.9rem; color: var(--muted); }

/* ---------- Timeline ---------- */
.timeline-grid { display: grid; grid-template-columns: 1fr 1fr; gap: 48px; }
.timeline-grid .group-title { margin-top: 0; }
.timeline { position: relative; padding-left: 28px; border-left: 2px solid var(--line); }
.timeline li { position: relative; padding-bottom: 28px; }
.timeline li:last-child { padding-bottom: 0; }
.timeline li::before {
  content: ""; position: absolute; left: -35px; top: 6px; width: 12px; height: 12px; border-radius: 50%;
  background: var(--accent); box-shadow: 0 0 0 4px var(--bg);
}
.section-alt .timeline li::before { box-shadow: 0 0 0 4px var(--bg-alt); }
.when { display: inline-block; font-size: 0.8rem; font-weight: 700; color: var(--accent-text); letter-spacing: 0.04em; margin-bottom: 6px; }
.timeline h4 { margin-bottom: 2px; }
.where { color: var(--text); font-weight: 500; font-size: 0.95rem; margin-bottom: 6px; }
.timeline p:not(.where) { color: var(--muted); font-size: 0.97rem; margin: 0; }

/* ---------- Awards & affiliations ---------- */
.awards-grid { display: grid; grid-template-columns: 1.2fr 1fr; gap: 40px; align-items: start; }
.award-list li, .affil-list li { display: grid; grid-template-columns: 96px 1fr; gap: 16px; padding: 16px 0; border-bottom: 1px solid var(--line); }
.award-list li:last-child, .affil-list li:last-child { border-bottom: none; }
.award-list .when, .affil-list .when { margin: 2px 0 0; }
.award-list h4, .affil-list h4 { margin-bottom: 2px; }
.award-list p, .affil-list p { margin: 0; color: var(--muted); font-size: 0.95rem; }

/* ---------- Skills ---------- */
.skills-grid { display: grid; grid-template-columns: repeat(2, 1fr); gap: 20px; }
.skill-group { background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); padding: 22px 24px; }
.skill-group h3 { font-size: 1rem; margin-bottom: 14px; }
.skill-group .tags { margin-top: 0; }

/* ---------- Publications ---------- */
.pubs { display: grid; gap: 14px; }
.pubs li { background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); padding: 20px 24px; }
.pub-title { font-weight: 600; margin-bottom: 4px; }
.pub-meta { color: var(--muted); font-size: 0.93rem; margin-bottom: 8px; }
.pub-links { display: flex; flex-wrap: wrap; gap: 14px; }

/* ---------- Contact ---------- */
.contact-grid { display: grid; grid-template-columns: 1fr 1.3fr; gap: 40px; align-items: start; }
.contact-list { display: grid; gap: 14px; }
.contact-list li { background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius-sm); padding: 14px 18px; display: grid; gap: 2px; }
.contact-label { font-size: 0.74rem; font-weight: 700; text-transform: uppercase; letter-spacing: 0.08em; color: var(--accent-text); }
.social-links { display: flex; flex-wrap: wrap; gap: 8px 20px; margin-top: 6px; }
.social-links a { display: inline-flex; align-items: center; gap: 7px; font-weight: 600; }
.social-links svg { color: var(--accent-text); flex: none; }
.contact-form { background: var(--bg-elev); border: 1px solid var(--line); border-radius: var(--radius); padding: 24px; display: grid; gap: 14px; }
.form-row { display: grid; grid-template-columns: 1fr 1fr; gap: 14px; }
.contact-form label { display: grid; gap: 6px; font-size: 0.85rem; font-weight: 600; color: var(--muted); }
.contact-form input, .contact-form textarea {
  font: inherit; font-size: 1rem; color: var(--text); background: var(--bg); border: 1px solid var(--line);
  border-radius: var(--radius-sm); padding: 11px 14px; width: 100%; resize: vertical;
}
.contact-form input:focus, .contact-form textarea:focus { outline: none; border-color: var(--accent); box-shadow: 0 0 0 3px var(--accent-soft); }
.contact-form button { justify-self: start; }
.form-note { font-size: 0.85rem; color: var(--muted); margin: 0; }

/* ---------- Footer ---------- */
.site-footer { border-top: 1px solid var(--line); padding: 28px 0; color: var(--muted); font-size: 0.9rem; }
.footer-inner { display: flex; flex-wrap: wrap; justify-content: space-between; gap: 8px; }
.footer-inner p { margin: 0; }

/* ---------- Reveal animation ---------- */
.reveal { opacity: 0; transform: translateY(14px); transition: opacity .5s ease, transform .5s ease; }
.reveal.in { opacity: 1; transform: none; }
@media (prefers-reduced-motion: reduce) { .reveal { opacity: 1; transform: none; transition: none; } }

/* ---------- Responsive ---------- */
@media (max-width: 960px) {
  .hero-grid { grid-template-columns: 1fr; gap: 36px; }
  .hero-photo { order: -1; }
  .photo-frame { width: min(280px, 70vw); }
  .about-grid, .timeline-grid, .contact-grid, .awards-grid { grid-template-columns: 1fr; gap: 32px; }
  .cards-3 { grid-template-columns: 1fr 1fr; }
  .cards-4 { grid-template-columns: 1fr 1fr; }
  .gallery { grid-template-columns: 1fr 1fr; }
}
@media (max-width: 760px) {
  body { font-size: 16px; }
  .nav-toggle { display: inline-flex; }
  .site-nav {
    position: absolute; left: 0; right: 0; top: 68px; flex-direction: column; align-items: stretch;
    background: var(--bg-elev); border-bottom: 1px solid var(--line); padding: 12px 16px 16px; gap: 2px;
    display: none; box-shadow: var(--shadow);
  }
  .site-nav.open { display: flex; }
  .site-nav a:not(.btn) { padding: 12px; }
  .nav-cv { margin: 8px 0 0; justify-content: center; }
  .cards-2, .cards-3, .cards-4, .skills-grid, .form-row { grid-template-columns: 1fr; }
  .gallery { grid-template-columns: 1fr; }
  .hero-actions .btn { flex: 1 1 auto; justify-content: center; }
  .award-list li, .affil-list li { grid-template-columns: 1fr; gap: 4px; }
}