/* ---------- Tokens ---------- */

:root {
  --bg: #f4f7fc;
  --surface: #ffffff;
  --ink: #0f1e36;
  --muted: #5b6b84;
  --rule: #dce5f1;
  --rule-strong: #c3d2e7;
  --accent: #1f5fbf;
  --accent-soft: #e7effb;
  --on-accent: #ffffff;
  --wide: 60rem;
  --radius: 14px;
}

@media (prefers-color-scheme: dark) {
  :root {
    --bg: #0b1322;
    --surface: #101b2f;
    --ink: #e4ebf5;
    --muted: #8d9bb3;
    --rule: #1c2a42;
    --rule-strong: #2a3b58;
    --accent: #7fb0ff;
    --accent-soft: #16253f;
    --on-accent: #0b1322;
  }
}

/* ---------- Base ---------- */

*, *::before, *::after { box-sizing: border-box; }

[hidden] { display: none !important; }

html {
  -webkit-text-size-adjust: 100%;
  scroll-behavior: smooth;
}

@media (prefers-reduced-motion: reduce) {
  html { scroll-behavior: auto; }
}

body {
  margin: 0;
  background: var(--bg);
  color: var(--ink);
  font-family: 'Inter', -apple-system, BlinkMacSystemFont, 'Segoe UI', sans-serif;
  font-size: 16px;
  line-height: 1.7;
  -webkit-font-smoothing: antialiased;
}

a {
  color: var(--accent);
  text-decoration: underline;
  text-decoration-color: var(--rule-strong);
  text-underline-offset: 3px;
  transition: text-decoration-color 0.2s ease, color 0.2s ease, background-color 0.2s ease, border-color 0.2s ease;
}

a:hover { text-decoration-color: var(--accent); }

a:focus-visible {
  outline: 2px solid var(--accent);
  outline-offset: 2px;
}

p { margin: 0 0 1rem; }
p:last-child { margin-bottom: 0; }

.muted { color: var(--muted); }

.page {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 4.5rem 1.75rem 5rem;
}

.card {
  background: var(--surface);
  border: 1px solid var(--rule);
  border-radius: var(--radius);
}

/* ---------- Top bar ---------- */

.topbar {
  position: sticky;
  top: 0;
  z-index: 10;
  background: color-mix(in srgb, var(--bg) 88%, transparent);
  backdrop-filter: blur(10px);
  -webkit-backdrop-filter: blur(10px);
  border-bottom: 1px solid var(--rule);
}

.topbar-inner {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0.85rem 1.75rem;
  display: flex;
  justify-content: space-between;
  align-items: center;
  flex-wrap: wrap;
  gap: 0.75rem 1rem;
}

.pills,
.tabs {
  display: flex;
  margin: 0;
  padding: 0;
  list-style: none;
}

.pills { gap: 0.5rem; }

.pill {
  display: inline-block;
  padding: 0.3rem 0.95rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--ink);
  text-decoration: none;
  border: 1px solid var(--rule-strong);
  border-radius: 999px;
}

.pill:hover {
  color: var(--accent);
  border-color: var(--accent);
  background: var(--accent-soft);
}

.tabs {
  border: 1px solid var(--rule-strong);
  border-radius: 8px;
  overflow: hidden;
  background: var(--surface);
}

.tabs li + li { border-left: 1px solid var(--rule-strong); }

.tab {
  display: block;
  padding: 0.35rem 1.05rem;
  font-size: 0.8125rem;
  font-weight: 500;
  color: var(--muted);
  text-decoration: none;
}

.tab:hover {
  color: var(--ink);
  background: var(--accent-soft);
}

.tab[aria-current="true"] {
  color: var(--on-accent);
  background: var(--accent);
}

/* ---------- Hero (About) ---------- */

.hero {
  display: grid;
  grid-template-columns: minmax(12rem, 17rem) 1fr;
  gap: 3rem;
  align-items: start;
  scroll-margin-top: 6rem;
}

.portrait {
  position: relative;
  margin: 0;
  aspect-ratio: 4 / 5;
  border-radius: var(--radius);
  border: 1px solid var(--rule);
  overflow: hidden;
  background: linear-gradient(160deg, var(--accent-soft), var(--rule-strong));
}

.portrait img {
  position: relative;
  display: block;
  width: 100%;
  height: 100%;
  object-fit: cover;
}

.portrait-fallback {
  position: absolute;
  inset: 0;
  display: grid;
  place-items: center;
  font-family: 'Newsreader', Georgia, serif;
  font-size: 3.5rem;
  letter-spacing: 0.04em;
  color: var(--accent);
}

.name {
  font-family: 'Newsreader', Georgia, serif;
  font-size: 3rem;
  font-weight: 400;
  letter-spacing: -0.015em;
  line-height: 1.1;
  margin: 0.25rem 0 0.5rem;
}

.tagline {
  color: var(--muted);
  font-size: 0.9375rem;
  margin: 0 0 1.75rem;
}

.about-card { padding: 1.75rem 2rem; }

.card-label {
  font-size: 0.75rem;
  font-weight: 600;
  letter-spacing: 0.14em;
  text-transform: uppercase;
  color: var(--accent);
  margin: 0 0 0.875rem;
}

.facts {
  margin: 1.5rem 0 0;
  padding-top: 1.25rem;
  border-top: 1px solid var(--rule);
  display: grid;
  gap: 0.625rem;
  font-size: 0.9375rem;
}

.facts div {
  display: grid;
  grid-template-columns: 6.5rem 1fr;
  gap: 1rem;
}

.facts dt {
  color: var(--muted);
  font-size: 0.8125rem;
  padding-top: 0.1rem;
}

.facts dd { margin: 0; }

.facts .muted { white-space: nowrap; }

/* ---------- Sections ---------- */

.section {
  margin-top: 5.5rem;
  scroll-margin-top: 6rem;
}

.section-title {
  font-family: 'Newsreader', Georgia, serif;
  font-size: 1.875rem;
  font-weight: 400;
  letter-spacing: -0.01em;
  margin: 0 0 1.5rem;
  padding-bottom: 0.75rem;
  border-bottom: 1px solid var(--rule);
}

/* ---------- Research entries ---------- */

.entry {
  padding: 1.5rem 1.75rem;
  border-left: 3px solid var(--accent);
}

.entry + .entry { margin-top: 1rem; }

.entry-head {
  display: flex;
  justify-content: space-between;
  align-items: baseline;
  gap: 1.5rem;
}

.entry-title {
  font-size: 1.0625rem;
  font-weight: 500;
  margin: 0;
}

.entry-date {
  font-size: 0.8125rem;
  color: var(--muted);
  white-space: nowrap;
  font-variant-numeric: tabular-nums;
}

.entry-meta {
  font-family: 'Newsreader', Georgia, serif;
  font-style: italic;
  font-size: 1.0625rem;
  color: var(--muted);
  margin: 0.125rem 0 0.5rem;
}

.entry-meta:last-child { margin-bottom: 0; }

.entry-body {
  font-size: 0.9375rem;
  margin: 0;
}

/* ---------- Projects ---------- */

.project-list {
  display: grid;
  gap: 1rem;
}

.project {
  display: flex;
  flex-direction: column;
  padding: 1.5rem 1.75rem;
  transition: border-color 0.2s ease;
}

.project:hover { border-color: var(--rule-strong); }

.project-title {
  font-size: 1.0625rem;
  font-weight: 500;
  margin: 0;
}

.project-meta {
  font-family: 'Newsreader', Georgia, serif;
  font-style: italic;
  font-size: 1.0625rem;
  color: var(--muted);
  margin: 0.125rem 0 0.875rem;
}

.project-points {
  display: grid;
  gap: 0.5rem;
  margin: 0 0 1.25rem;
  padding-left: 1.1rem;
  font-size: 0.9375rem;
}

.project-points li::marker { color: var(--accent); }

.project-title + .project-points { margin-top: 0.75rem; }

.tags {
  display: flex;
  flex-wrap: wrap;
  gap: 0.375rem;
  margin: 0 0 1.25rem;
  padding: 0;
  list-style: none;
}

.tags li {
  font-size: 0.75rem;
  font-weight: 500;
  padding: 0.125rem 0.6rem;
  border-radius: 999px;
  color: var(--accent);
  background: var(--accent-soft);
}

.project-link {
  margin-top: auto;
  font-size: 0.875rem;
  font-weight: 500;
  text-decoration: none;
}

.project-link:hover { text-decoration: underline; }

/* ---------- Footer ---------- */

.footer {
  max-width: var(--wide);
  margin: 0 auto;
  padding: 0 1.75rem 3rem;
  font-size: 0.8125rem;
  color: var(--muted);
}

.footer p {
  padding-top: 2rem;
  border-top: 1px solid var(--rule);
}

/* ---------- Responsive ---------- */

@media (max-width: 760px) {
  .hero {
    grid-template-columns: 1fr;
    gap: 2rem;
  }

  .portrait { max-width: 13rem; }
}

@media (max-width: 480px) {
  .topbar-inner { padding: 0.75rem 1.25rem; }
  .page { padding: 2.5rem 1.25rem 3.5rem; }
  .footer { padding: 0 1.25rem 2.5rem; }
  .footer p { padding-top: 1.5rem; }
  .name { font-size: 2.4rem; }
  .about-card { padding: 1.5rem 1.25rem; }
  .facts div { grid-template-columns: 1fr; gap: 0; }
  .entry,
  .project { padding: 1.25rem; }
  .entry-head { flex-direction: column; gap: 0.125rem; }
}