/* ============================================================
   Theme tokens
   ============================================================ */
:root {
  --bg: #ffffff;
  --surface: #f6f7f9;
  --text: #1a1a1a;
  --text-muted: #5a6472;
  --text-faint: #939bab;
  --border: #e4e7ec;
  --accent: #2563eb;
  --accent-soft: #dbeafe;
  --tag-bg: #eef2ff;
  --tag-text: #4338ca;
  --max-width: 720px;
  --radius: 12px;
}

[data-theme="dark"] {
  --bg: #0e1116;
  --surface: #161b22;
  --text: #e6edf3;
  --text-muted: #9aa5b1;
  --text-faint: #6b7480;
  --border: #262c36;
  --accent: #6ea8fe;
  --accent-soft: #17233b;
  --tag-bg: #1c2333;
  --tag-text: #a5b4fc;
}

/* ============================================================
   Base
   ============================================================ */
* { box-sizing: border-box; }

html { scroll-behavior: smooth; }

body {
  margin: 0;
  background: var(--bg);
  color: var(--text);
  font-family: "Inter", system-ui, -apple-system, sans-serif;
  font-size: 17px;
  line-height: 1.65;
  -webkit-font-smoothing: antialiased;
  transition: background 0.2s ease, color 0.2s ease;
}

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

.container {
  max-width: var(--max-width);
  margin: 0 auto;
  padding: 4rem 1.5rem 5rem;
}

/* ============================================================
   Theme toggle
   ============================================================ */
.theme-toggle {
  position: fixed;
  top: 1rem;
  right: 1rem;
  width: 40px;
  height: 40px;
  border-radius: 50%;
  border: 1px solid var(--border);
  background: var(--surface);
  color: var(--text);
  font-size: 1.1rem;
  cursor: pointer;
  display: grid;
  place-items: center;
  transition: background 0.2s ease, transform 0.15s ease;
}
.theme-toggle:hover { transform: scale(1.08); }

/* ============================================================
   Hero
   ============================================================ */
.hero {
  display: flex;
  gap: 1.75rem;
  align-items: center;
  margin-bottom: 3.5rem;
}
.hero__photo {
  width: 128px;
  height: 128px;
  border-radius: 50%;
  object-fit: cover;
  border: 1px solid var(--border);
  flex-shrink: 0;
}
.hero__name {
  font-family: "Newsreader", Georgia, serif;
  font-size: 2.4rem;
  line-height: 1.1;
  margin: 0 0 0.35rem;
  letter-spacing: -0.01em;
}
.hero__role {
  margin: 0 0 0.6rem;
  font-size: 1.05rem;
  color: var(--text-muted);
}
.hero__tagline {
  margin: 0 0 1rem;
  color: var(--text);
}
.hero__links {
  display: flex;
  flex-wrap: wrap;
  gap: 0.4rem 1rem;
  font-size: 0.95rem;
}
.hero__links a {
  color: var(--text-muted);
  font-weight: 500;
}
.hero__links a:hover { color: var(--accent); }

/* ============================================================
   Sections
   ============================================================ */
.section { margin-bottom: 3rem; }
.section__title {
  font-family: "Newsreader", Georgia, serif;
  font-size: 1.5rem;
  margin: 0 0 1rem;
  padding-bottom: 0.4rem;
  border-bottom: 1px solid var(--border);
}
.section__note {
  color: var(--text-muted);
  font-size: 0.95rem;
  margin-top: -0.4rem;
}

/* ============================================================
   Publications
   ============================================================ */
.pub-list {
  list-style: none;
  margin: 0;
  padding: 0;
}
.pub {
  display: flex;
  gap: 1.25rem;
  padding: 1rem 0;
  border-bottom: 1px solid var(--border);
}
.pub:last-child { border-bottom: none; }
.pub__meta {
  flex-shrink: 0;
  width: 84px;
  text-align: right;
  padding-top: 0.15rem;
}
.pub__venue {
  display: block;
  font-weight: 600;
  font-size: 0.85rem;
}
.pub__year {
  display: block;
  color: var(--text-muted);
  font-size: 0.85rem;
}
.pub__body { flex: 1; }
.pub__title {
  font-size: 1.05rem;
  margin: 0 0 0.2rem;
  line-height: 1.35;
}
.pub__authors {
  margin: 0 0 0.35rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}
.pub__authors sup {
  font-weight: 600;
  color: var(--accent);
}
.pub__contrib {
  margin: 0 0 0.35rem;
  color: var(--text-faint);
  font-size: 0.76rem;
}
.pub__note {
  margin: 0 0 0.35rem;
  color: var(--text-muted);
  font-size: 0.88rem;
  font-style: italic;
}
.pub__links {
  margin: 0;
  display: flex;
  gap: 0.9rem;
  font-size: 0.9rem;
}

/* ============================================================
   Timeline (experience)
   ============================================================ */
.timeline {
  list-style: none;
  margin: 0;
  padding: 0;
}
.timeline__item {
  display: flex;
  gap: 1.25rem;
  padding: 0.85rem 0;
}
.timeline__when {
  flex-shrink: 0;
  width: 130px;
  color: var(--text-muted);
  font-size: 0.9rem;
  padding-top: 0.15rem;
}
.timeline__what h3 {
  margin: 0 0 0.15rem;
  font-size: 1.05rem;
}
.timeline__what p {
  margin: 0;
  color: var(--text-muted);
  font-size: 0.95rem;
}

/* ============================================================
   Project cards
   ============================================================ */
.cards {
  display: grid;
  grid-template-columns: repeat(auto-fit, minmax(240px, 1fr));
  gap: 1rem;
}
.card {
  display: flex;
  flex-direction: column;
  padding: 1.25rem;
  background: var(--surface);
  border: 1px solid var(--border);
  border-radius: var(--radius);
  color: inherit;
  transition: border-color 0.15s ease, transform 0.15s ease;
}
.card:hover {
  border-color: var(--accent);
  transform: translateY(-2px);
}
.card__title { margin: 0 0 0.4rem; font-size: 1.05rem; }
.card__desc {
  margin: 0 0 0.75rem;
  color: var(--text-muted);
  font-size: 0.95rem;
}
.card__tag {
  display: inline-block;
  align-self: flex-start;
  font-size: 0.78rem;
  font-weight: 600;
  color: var(--tag-text);
  background: var(--tag-bg);
  padding: 0.15rem 0.6rem;
  border-radius: 999px;
}
.card__links {
  margin: 0.85rem 0 0;
  display: flex;
  gap: 0.9rem;
  font-size: 0.9rem;
}

/* ============================================================
   Footer
   ============================================================ */
.footer {
  margin-top: 4rem;
  padding-top: 1.5rem;
  border-top: 1px solid var(--border);
  color: var(--text-muted);
  font-size: 0.9rem;
  text-align: center;
}

/* ============================================================
   Responsive
   ============================================================ */
@media (max-width: 560px) {
  .container { padding: 3rem 1.25rem 4rem; }
  .hero {
    flex-direction: column;
    text-align: center;
    gap: 1.25rem;
  }
  .hero__links { justify-content: center; }
  .pub, .timeline__item { flex-direction: column; gap: 0.35rem; }
  .pub__meta { width: auto; text-align: left; }
  .pub__venue, .pub__year { display: inline; margin-right: 0.5rem; }
  .timeline__when { width: auto; }
}